Proposal of new genera and species of the subfamily Diosaccinae (Copepoda: Harpacticoida: Miraciidae)

Representatives of several genera of the family Miraciidae (Copepoda: Harpacticoida) were found in sediment samples taken in the year 2019 from a coastal system in north-western Mexico. The subfamily Diosaccinae (Miraciidae) was by far the most diverse taxon followed by the subfamily Stenheliinae (Miraciidae). Here we report on a new miraciid species, Typhlamphiascus medici sp. nov., and provide a new amended diagnosis for Typhlamphiascus Lang, 1944 along with a key to its species. Additionally, Typhlamphiascus lamellifer lamellifer (Sars, 1911) and T. l. capensis Kunz, 1975 are considered as distinct species and the latter is given full species rank. Upon preliminary inspection, another diosaccin species was thought to be a derived form of Bulbamphiascus Lang, 1944. This promoted us to perform a more in-depth phylogenetic analysis. Our results showed that the new presumed derived form of Bulbamphiascus represents a new genus, Spinodiosaccus gen. nov. and that the genus Bulbamphiascus, which we propose a new amended diagnosis for, could be split into different genera. Also, the possible relationships amongst the different diosaccin clades found during our analyses are commented. Three new genera are proposed: Spinopedia gen. nov., Pallarica gen. nov. and Dinetia gen nov. We give a brief ecological analysis on the distribution of T. medici sp. nov. and S. primus gen. et sp. nov. in the Urías system.


Laboratory analyses
Sample processing and taxonomy Each sample was sieved through 500 and 38 μm sieves to separate macro-and meiofauna. Meiofauna was extracted through centrifugation with Ludox ® HS-40 following Burgess (2001) and Rohal et al. (2016) and preserved in pure ethanol. Meiofauna was sorted at a magnifi cation of 40 × using an Olympus SZX12 stereo microscope equipped with a DF PLAPO 1 × objective and WHS10 × eyepieces, and harpacticoid copepods were stored separately in 1 ml vials with pure ethanol. Illustrations and fi gures were made from whole individuals and its dissected parts using a Leica DMLB microscope equipped with L PLAN 10 × eyepieces, an N PLAN 100 × oil immersion objective, and a drawing tube. The dissected parts were mounted on separate slides using lactophenol as mounting medium. Huys & Boxshall (1991) was followed for general terminology.

Statistical analyses
Spearman's correlation coeffi cient was calculated between the density of each species and the environmental variables using Minitab ® Statistical Software ver. 19.2020. 1 (www.minitab.com). Diff erences in density of T. medici sp. nov. and S. primus gen. et sp. nov. between sampling stations were assessed through a non-parametric one-way analysis of variance. Principal coordinates analysis (PCoA) between the Euclidean distance dissimilarity matrix for the environmental variables and the Bray-Curtis similarity matrix combined with a CLUSTER analysis for biological samples was used to assess the eff ects of the environmental variables that had major eff ects on the distribution of T. medici sp. nov. and S. primus gen. et sp. nov. Non-parametric one-way analysis of variance and PCoA were performed using PRIMER ver. 7 and PERMANOVA+ (Clarke & Gorley 2015).
Rostrum not fused to cephalothorax, triangular, elongate, as long as fi rst and second antennulary segments combined, with pointed tip, with one subdistal sensilla on each side. Female genital and third urosomites distinct dorsally and/or laterally, completely fused ventrally forming genital double-somite; genital and third urosomites separated in males. Length : width ratio of caudal rami variable, from 1 : 1 to 3 : 1.
Female antennule seven-to nine-segmented, with aesthetasc and seta fused basally on fourth segment, and with apical acrothek on last segment. Male antennule haplocer, eight-ten-segmented, with aesthetasc and seta fused basally on fi fth segment, and with apical acrothek on last segment. Antennulary setae typically smooth, except for few slightly setulose setae on penultimate and last articles in females and males. Antenna with allobasis; exopod three-segmented, armature formula 1-0-1,3,0. Mandibular palp Table 4 (continued on next page). Character matrix used to reconstruct the generic phylogenetic relationships within the Diosaccinae. Characters are multistate. 0 = plesiomorphic; 1-n = apomorphic; ? = unknown. biramous; endopod one-segmented, larger than exopod; exopod two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites; endopod two-segmented. Maxilliped subchelate; (syn)coxa with two to four, basis with two setae; endopod one-segmented, with claw and variable number of accompanying setae. P1-P4 with three-segmented rami. Male P1 basis sexually dimorphic, with normal or modifi ed (elongate, blunt) inner spine, without or with variable number of inner accessory spines (two-eight). Male P2 sexually dimorphic, two-segmented; fi rst segment with one inner seta, second segment with two inner setae, two subdistal elements (one of which thick and blunt) and two elements (one medial, one apical) issuing from elongate cylindrical extension fused to segment basally. P5 EXP typically longer than wide, with four to six setae in the female and male; P5 endopodal lobe with four to fi ve setae in the female, with two setae in the male; two innermost elements of the female P5 endopodal lobe and armature of the male P5 endopodal lobe bifurcate distally.

Characters
Armature formula of P1-P5 as follows: The report of eight setae on the female P5 EXP of T. blanchardi is most probably erroneous. 2 Typhlamphiascus typhlops is known to lack inner armature on the P4 ENP2. The inner seta of P4 ENP2 of T. capensis comb. nov. might have become detached from the supporting segment as indicated by the interrupted cuticle (Kunz 1975).
Sexual dimorphism expressed in the male antennule (see above), P1 basis, P2 ENP (see above), P5 (see above), structure of P6, and in the separated genital and third urosomites.

Etymology
The specifi c epithet from the Latin 'medicī', 'doctor', 'physician', is dedicated in honour and to the memory of all physicians and health personnel for their self-sacrifi ce during the fi ght against the COVID-19 pandemic. It is in the genitive singular, gender masculine.

Description
With small unornamented coxa. Allobasis with remains of former division between basis and fi rst endopodal segment, slightly longer than free endopodal segment, with outer slender spinules proximally, without abexopodal seta. Exopod three-segmented; fi rst segment longer than second and third segments combined, second segment smallest; fi rst and second segments unornamented, the former with one, the latter without seta; third segment with subapical row of spinules, armed with three setae, of which one bare, the other two bipinnate. Free endopodal segment with proximal and subdistal inner strong spinules as shown, and with two outer frills; armed with two lateral inner fl agellate spines and two slender setae (the latter set close to each other), one inner apical fl agellate spine, three single geniculate setae, one slender bipinnate short seta and one strongly spinulose geniculate outer seta fused basally to slender pinnate element. With well-developed gnathobasis bearing strong multi-and bicuspidate teeth as shown, subdistally with two small slender setae and two spinules medially, and with one strongly spinulose element. Basis massive, with spinules as depicted, with three inner setae. Exopod twosegmented; fi rst segment longer than second, the former with one lateral and one distal seta, the latter with one apical element. Endopod one-segmented, visibly larger that exopod; with two lateral and six distal setae. M (Fig. 4B). With arthrite ornamented with some slender spinules and armed with two surface setae, seven distal spines as shown, one spinulose element and one recurved stiff pinnate seta. Coxal endite with three setae. Basis with spinular row as depicted and armed with two lateral, one subdistal and three distal elements, one of which visibly stronger. Rami one-segmented, exopod with two, endopod with four elements -two distal, one inner subdistal and one inner medial seta. M (Fig. 5A). With large syncoxa ornamented with small outer spinules; with three endites; proximal endite smallest, with three setae; middle and distal endites nearly subequal in length, the former with two, the latter with three setae. Basis drawn out into strong claw with minute pinnae, additionally with strong spine bearing one long spinule and two slender setae -one anterior, one posterior. Endopod two-segmented; fi rst segment with two, second segment with one lateral and four distal setae. M (Fig. 5B). Subchelate. Praecoxa small, trapezoidal, ornamented with slender outer spinules. Coxa trapezoidal, with proximal, medial and subdistal spinules as shown; with two inner small setae issuing at distal fourth and two long apical setae. Basis longer than coxa, oval, with outer slender longitudinal spinules, and one posterior and one anterior row of spinules as depicted, with one medial inner and one subdistal inner seta. Endopod one-segmented, elongate, with three setae -one lateral, one subdistal and one small distal -and apical claw. P1 ( Fig. 6A-B). With broad unornamented intercoxal sclerite (Fig. 6B). Coxa massive, with several spinular rows as shown. Basis with inner and outer spinulose spines; with slender long inner spinules proximally and close to insertion of inner spine, and with shorter but stronger spinules at base of inner and outer seta, and distally on medial distal rounded protrusion. Exopod three-segmented, arising at a lower level than that of the endopod and reaching slightly beyond ENP1; ENP : EXP length ratio 1.5; exopodal segments subequal in length, with strong outer spinules as shown; fi rst segment without, second segment with one inner seta with comb tip; third segment with fi ve elements. Endopod three-segmented, arising from pedestal; ENP1 about four times as long as wide, as long as second and third segments combined, with outer and inner longitudinal rows of slender spinules, with one inner stiff , long, strongly pectinate seta; second and third segments ornamented with strong outer spinules as shown, the former shorter, nearly as long as wide and half as long as the latter, with one inner, slender, short seta; third segment elongate with one inner distal slender seta, one apical long element and one outer distal spine. P2 (Fig. 6B). Narrow intercoxal sclerite (not shown) with acute distal projection on each side, largely as in P3. Praecoxa (not shown) as in P3. Coxa with three anterior rows of spinules -one proximal and two medial transverse -and with posterior small spinules close to proximal outer margin. Basis with long slender spinules proximally close to inner margin, with small spinules between rami, and with comparatively larger spinules at base of exopod and at base of outer pinnate spine. Rami threesegmented, endopod and exopod subequal in absolute length. Exopod three-segmented, arising at a lower level than that of the endopod, not reaching tip of ENP; exopodal segments with strong outer spinules as shown; EXP1 and EXP2 with outer distal acute projection, on EXP1 shorter, both segments with coarse inner distal hyaline frill and inner seta with comb tip, on EXP1 visibly shorter; EXP3 with six elements -three outer spines, two apical elements and one inner seta with comb tip. Endopod three-segmented, arising from pedestal; endopodal segments with strong outer spinules as shown; ENP1 shortest, as long as wide, with small distal spinules close to small inner projection, without outer distal projection nor inner hyaline frill, with one short inner seta; ENP2 elongate, 1.7 times as long as wide and 0.6 times as long as ENP3, with strong outer spinules and with small spinules at base of outer distal acute projection, with coarse inner distal frill, with two inner setae of which proximal one short; ENP3 longest, elongate, 4.8 times as long as wide, with medial outer pore, with four elements (one inner and two apical setae, and one outer spine), with acute projection between outer spine and inner apical seta. P3 (Fig. 7A). Narrow intercoxal sclerite with acute distal projection on each side. Praecoxa small, with transverse distal row of slender spinules close to outer margin. Coxa and basis as in P2 except for outer setiform element of basis on P3. Rami three-segmented, endopod and exopod subequal in absolute length. Exopod largely as in P2 except for additional posterior pore on P3 EXP1. Endopod largely as in P2 except for one inner seta only on P3 ENP2 and two inner setae on P3 ENP3. P4 (Fig. 7B). With intercoxal sclerite, praecoxa, coxa and basis as in P3. Exopod longer than endopod; EXP : ENP length ratio 1.3; largely as in P3 except for two inner setae on P4 EXP3 of which distalmost one visibly thicker and strongly pectinate. Endopod reaching slightly beyond middle of EXP3; largely as in P3 except for stiff er inner seta on P4 ENP2, and one inner seta only on P4 ENP3.
Armature formula of P1-P4 as follows: 2B). With outer seta of BENP arising from long setophore. Endopodal lobe triangular, reaching middle of exopod; with small spinules along outer margin and at base of inner setae; with fi ve elements -one outer subdistal, one apical and one inner subdistal normal seta, and two inner bifurcate elements. Exopod elongate, 2.8 times as long as wide; with spinules along inner margin and with few proximal outer spinules; with six elements -three outer slender, short setae, two apical elements, of which outermost one shorter, and one inner seta. P6 ( Fig. 2A). With three setae -one short bipinnate element, and one medial and one inner bare seta of which medial one shorter.

G
. Total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 675 to 900 μm (mean 731 μm; n = 5; total body length of allotype 680 μm). P (Fig. 8A). As in female. U ( Fig. 8A-B). As in female except for second -P6-bearing somite -and third urosomites separated, and for continuous spinular rows and hyaline frill of third and fourth urosomites ventrally.
P1. As in female except for basis without slender inner, long spinules, and with three inner accessory spines and a proximal inner, nose-like outgrowth in the male (Fig. 9C).
P2 EXP (not shown). As in female. Endopod (Fig. 10A) sexually dimorphic, two-segmented; ENP1 0.7 times length of ENP2, with sinuous inner margin, with proximal and medial outer slender spinules, with one short inner seta; ENP2 oval, with longitudinal row of outer slender, long spinules, with two short inner setae arising from pedestal, subdistally with one posterior strong, blunt element, and with one anterior stiff , bare seta with subapical rounded expansion and pointed tip, with one lateral and one apical seta arising from elongate cylindrical extension fused to segment basally.

GÓMEZ S. et al., On new genera and species of Harpacticoida
23 P5 (Fig. 10B). With outer seta of baseoendopod arising from long setophore. Endopodal lobe reaching middle of exopod, with inner and outer spinules as shown, with two distal bifurcate setae of which outermost one slightly shorter. Exopod rectangular, 2.5 times as long as wide, with longitudinal row of inner spinules and medial pore, with few proximal outer spinules, with six setae -three outer elements of which proximalmost visibly longer, one subdistal outer seta arising from setophore and two distal setae of which innermost one ⅓ length of outermost and with bifurcate tip. P6 (Fig. 8B). Asymmetrical, each leg with three setae of which innermost one shortest and spiniform, medial and outermost ones slender, medial one longest.

Variability
The left dorsal sensilla of the anal somite of the holotype is situated more proximally than the right sensilla. One female possesses fi ve instead of six setae on one mandibular endopod and two instead of three maxillary endites on one maxilla.  Miraciidae: Diosaccinae. Body fusiform. Rostrum not fused to cephalothorax, elongate, almost as long as the fi rst, second and third antennulary segments combined, with one subdistal sensilla on each side issuing at the third quarter of its length. Pro-and urosomites without extensions; with a fl exible unsclerotized cuticle between prosome and urosome, the latter seemingly more evident in the male. Female genital double-somite (genital -second urosomite -and third urosomites fused) completely fused ventrally, with a dorsolateral cuticular rib marking former division between somites. Anal somite trapezoidal, without anal operculum. Caudal rami short, 1.6 times as wide as long in dorsal view, unornamented, with slender tube pore ventrally; with seven setae. Female antennule eight-segmented, with aesthetasc and seta fused basally on fourth segment and with apical acrothek on last segment. Male antennule haplocer, 11-segmented, with aesthetasc and seta fused basally on fi fth segment and with apical acrothek on last segment. Antennulary setae typically smooth. Antenna with allobasis; exopod three-segmented, armature formula 1-1-1,3,0. Mandibular palp biramous; endopod one-segmented, exopod two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites; ENP one-segmented. Maxilliped subchelate; (syn)coxa with four, basis with two setae; ENP one-segmented, with claw and three accompanying setae. P1-P4 with three-segmented rami. P1-P2 EXP shorter than endopod, P3 EXP and ENP of approximately the same length, P4 ENP shorter than EXP. Male P1 basis sexually dimorphic, with inner unipinnate spine and inner modifi ed accessory spine. Male P2 sexually dimorphic, two-segmented; fi rst segment with one inner seta; second segment with two inner, one inner subdistal almost straight element, and two setae (one medial, one apical) issuing from elongate cylindrical extension fused to segment basally, and one strong outer subdistal spine, the latter strongly tapering distally. P2-P4 EXP1 without, EXP2 with inner seta; P2-P4 ENP1 with inner seta; P2 ENP2 with two, P3-P4 ENP2 with one inner seta, inner distal seta of EXP3 visibly shorter than other elements of same segment. Both P5 EXP separated in the female, baseoendopods fused medially in the male; rami of P5 distinct in both sexes; P5 EXP with six setae in both sexes, whip-like in the female, two medial outer elements transformed into short spines in the male; P5 endopodal lobe with fi ve setae in the female, with two setae in the male.
Armature formula of P1-P5 as follows: Sexual dimorphism expressed in the male antennule, P1 basis, P2 ENP, P5, P6, and in the genital and third urosomite separated in males.

Etymology
The prefi x 'spino' from the Latin 'spīna', 'spine', refers to the two medial elements of the male P5 EXP modifi ed into strong short spines. Gender masculine.

Apomorphies of Spinodiosaccus gen. nov.
This new genus can easily be recognised by i) the male A1 with 11 segments resulting from the reexpression of the plesiomorphic condition, ii) the absence of an inner seta on the P1 EXP2 and iii) the absence of inner armature on P2-P4 EXP1.

Etymology
The specifi c epithet comes from the Latin 'prīmus', 'fi rst', and refers to the fi rst -and type -species described for Spinodiosaccus gen. nov. It is in the nominative singular, gender masculine.

G
. Total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 510 to 695 μm (mean 605.4 μm; n = 13; total body length of holotype 695 μm); habitus fusiform, widest at posterior end of cephalothorax in dorsal view, tapering posteriad (Fig. 11A). P (Fig. 11A, C). Consisting of cephalothorax, with fused fi rst pedigerous somite, and second to fourth free pedigerous somites; prosomites without expansions nor spinular ornamentation; posterior hyaline frill of cephalothorax, second and third pedigerous somites broad, of P4-bearing somite visibly narrower, with posterior margins plain; posterior frill of second and third pedigerous somites with transverse row of minute spinules. U (Figs 11A-D, 12A). Consisting of fi fth pedigerous somite (fi rst urosomite), genital doublesomite (genital -second urosomite -and third urosomites fused), two free urosomites, anal somite and caudal rami; urosomites without expansions. First urosomite narrower than preceding somites in dorsal view (Fig. 11A), without spinular ornamentation, with posterior sensilla as depicted, with one lateral pore on each side (Fig. 11C), posterior frill as in preceding somite dorsally and laterally (Fig. 11A, C). Genital double-somite (Figs 11A, C, 12A) rectangular, slightly longer than wide, with sensilla as shown, without spinular ornamentation; original division between anterior and posterior halves (second -genital -urosomite and third urosomite, respectively) marked by inner cuticular rib dorsally and laterally (Fig.  11A, C), completely fused ventrally (Fig. 12A); posterior half of genital double-somite with two dorsal pores and one lateroventral pore on each side, with posterior hyaline frill fi nely serrated and striated; P6 at anterior third of genital somite (anterior half of genital double-somite) and with genital fi eld as shown (Fig. 12A). Fourth urosomite largely as in posterior half of genital double-somite, but with additional medial pore ventrally and posterior ventrolateral transverse spinular row on frill (Figs 11A, C, 12A). Fifth urosomite without sensilla or spinules, with two dorsal and two ventral pores, posterior hyaline frill as in preceding somites (Figs 1A, C, 12A). Anal somite wider than long in dorsal view (Fig.  11A-B), without anal operculum, cleft medially dorsally (Fig. 11A-B) and ventrally (Fig. 12A), with two posterior sensilla dorsally, two dorsolateral pores (Fig. 11A-C) and two ventral pores (Fig. 12A), dorsally without spinules, with one ventrolateral and one short ventral spinular row on each side close to joint with caudal rami as shown (Fig. 12A). Caudal rami short, twice as wide as long in dorsal view (Fig. 11A-B), unornamented, with slender tube pore ventrally; with seven setae (Figs 1B, D, 2A) as follows: setae I and II situated almost medially on outer margin, the former very small and ventral to the latter; seta III displaced ventrally close to outer margin; setae IV and V normal, with fracture plane, the former shorter; seta VI arising at inner distal corner; dorsal seta VII issuing subdistally, close to inner margin, triarticulated. R (Fig. 13A). Not fused to cephalothorax, elongate, triangular, with blunt tip, with one sensillum arising at distal third on each side, without pore, reaching distal margin of second antennulary segment. A (Fig. 13B-C). Eight-segmented; all segments smooth, except for one proximal and one subdistal short spinular row on fi rst segment; all setae smooth; with two and four biarticulated setae on penultimate and last segments, respectively. Armature formula: 1(1); 2(10); 3(6); 4(3 + (1 + ae)); 5(2); 6(4); 7(4); 8(5 + acro). Acrothek consisting of two setae and one aesthetasc fused basally. A (Fig. 13D). With small coxa ornamented with outer spinules. Allobasis with remains of former division between basis and fi rst endopodal segment, as long as free endopodal segment, with outer spinules proximally, with one abexopodal seta. Exopod three-segmented; fi rst and third ones subequal in length, second segment smallest; fi rst and second segments unornamented, with one seta each; third segment unornamented, with four elements -one proximal bipinnate, one small subdistal and two distal spine-like elements. Free endopodal segment with proximal and subdistal inner strong spinules, and with row of outer small spinules as shown; armed with two lateral inner spines and two slender setae, the latter set close to each other, one inner apical spine, three single geniculate setae, one slender seta, and one strongly spinulose geniculate outer seta fused basally to slender pinnate element. M (Fig. 14A). With well-developed gnathobasis bearing strong multi-and bicuspidate teeth as shown, with two long spinules and one pinnate seta. Basis massive, with strong spinules, with three inner setae. Exopod two-segmented; fi rst segment longer than second, the former with one lateral and one distal seta, the latter with three apical elements. Endopod one-segmented, visibly larger than exopod; with two lateral and six distal setae, of which three fused basally.  (Fig. 14B). With arthrite ornamented with some slender spinules and armed with two surface setae (the latter indicated with an asterisk on fi gure), seven distal spines as shown, one spinulose element and one recurved, stiff pinnate seta. Coxal endite with two setae. Basis with spinular rows as depicted and armed with three lateral, one subdistal and three distal elements, one of which visibly stronger. Rami one-segmented, exopod unornamented and with two setae, endopod with longitudinal spinular row and with four elements -one inner subdistal, two distal and two outer subdistal setae.  (Fig. 14C). With large syncoxa ornamented with small outer spinules; with three endites; proximal endite smallest, with two setae; middle endite longer than proximal endite, with two setae; distal endite longest, with three setae. Basis drawn out into strong claw, additionally with pinnate spine, and two slender setae -one anterior, one posterior. Endopod one-segmented, with one proximal, one medial, one subdistal and four apical setae.  (Fig. 14D). Subchelate. Praecoxa small. Coxa elongate, with proximal, medial and subdistal spinules as shown; with two inner small setae issuing at middle of segment and two long apical setae. Basis longer than coxa, elongate, with medial row of small spinules and with longitudinal row of minute outer spinules, with one medial inner and one subdistal inner seta. Endopod one-segmented, elongate, with apical claw and three setae of diff erent lengths. P1 (Fig. 15A). With unornamented intercoxal sclerite. Coxa massive, with several spinular rows as shown. Basis with inner and outer spinulose spines; with strong spinules at top of crescentic medial extension, and with smaller spinules at base of inner spine. Exopod three-segmented, arising at a lower level than that of endopod and reaching tip of ENP2; ENP : EXP length ratio 1.2; exopodal segments with strong outer spinules as shown; second segment shortest, third segment longest; fi rst and second segments without inner armature, outer spine of fi rst segment longer than that of second segment; third segment with fi ve elements of which outer proximal and medial spines shorter than those of preceding segments. Endopod three-segmented, arising from pedestal; ENP1 about 2.8 times as long as wide, 1.4 times as long as second and third segments combined, with outer longitudinal row of strong spinules, with one inner stiff , long, strongly pectinate seta; second and third segments with strong outer spinules as shown, the former shorter, slightly longer than wide, with one inner seta; third segment elongate, 1.5 times as long as preceding segment, with one inner distal slender seta, one apical long element and one outer distal spine. P2 (Fig. 15B). With narrow intercoxal sclerite unornamented, with acute distal projection on each side. Coxa with three anterior rows of spinules. Basis with small inner acute outgrowth, with long slender inner spinules, with minute spinules at base of endopod, and with strong spinules between rami and at base of outer spine. Rami three-segmented, endopod longer than exopod. Exopod three-segmented, arising at a lower level than that of the endopod, reaching slightly above the middle of ENP3; exopodal segments with strong outer spinules as shown; EXP1 and EXP2 with outer distal acute projection, of EXP1 shorter, inner distal frill of fi rst segment coarse, of second segment small, fi rst segment without, second segment with inner seta; EXP3 with subdistal outer pore and seven elements -three outer spines, two apical elements and two inner setae of which distalmost one visibly shorter. Endopod three-segmented, arising from pedestal; endopodal segments with strong outer spinules as shown; ENP1 shortest, slightly longer than wide, with posterior small spinules proximally, with small inner distal spinules and with outer short acute projection, with one short inner seta; ENP2 elongate, twice as long as wide and 0.6 times as long as ENP3, with small inner distal spinules, with long outer distal acute projection, with two inner setae of which proximal shorter; ENP3 longest, elongate, six times as long as wide, with four elements (one inner and two apical setae, and one outer spine), with acute projection between outer spine and inner apical seta. P3 (Fig. 16A). With triangular praecoxa ornamented with transverse row of minute spinules. Intercoxal sclerite and coxa as in P2. Basis largely as in P2, but with smaller inner distal outgrowth and setiform outer element. Rami three-segmented, endopod slightly longer than exopod. Exopod largely as in P2. Endopod largely as in P2 except for lack of posterior spinules and with outer subdistal pore on ENP1, for inner seta of P3 ENP1 comparatively longer, for one long seta only on P3 ENP2, and for two inner setae on P3 ENP3. P4 (Fig. 16B). With intercoxal sclerite, praecoxa, and coxa as in P3. Basis as in P3 except for lack of inner distal outgrowth. Exopod longer than endopod; EXP : ENP length ratio 1.3; largely as in P3 except for three inner setae on P4 EXP3 of which medial one visibly thicker and strongly pectinate. Endopod reaching slightly beyond middle of EXP3; largely as in P3 except for one inner seta only on P4 ENP3.
Armature formula of P1-P4 as follows: 0-1-3,2,3 1-1-1,2,1 P5 (Fig. 12C). With outer seta of baseoendopod arising from setophore. Endopodal lobe triangular, reaching distal third of exopod; with small spinules along outer margin; with fi ve elements -one outer and one inner apical and one inner subdistal long setae, and two inner spiniform elements. Exopod elongate, 2.2 times as long as wide; with spinules at base of innermost seta and on outer margin proximally; with six elements -three outer slender setae, two apical elements of which outermost one shorter and one inner seta.
P6 (Fig. 12A). With three setae -one short bipinnate element, and one medial and one inner slender seta.

G
. Total body length measured from tip of rostrum to posterior margin of caudal rami ranging from 380 to 510 μm (mean 455 μm; n = 8; total body length of allotype 510 μm). P (Fig. 17A). As in female. U (Fig. 17A-B). As in female except for second -P6-bearing somite -and third urosomites separated, for medial row of eight ventral spinules on third urosomite, and for lack of spinules on hyaline frill of fourth urosomite.
P1. As in female except for basis without slender inner long spinules, without spinules at base of inner spine and with inner modifi ed accessory spine (Fig. 18C).
P2 EXP (not shown). As in female. Endopod (Fig. 18D) sexually dimorphic, two-segmented; ENP1 as long as ENP2 (excluding distal cylindrical extension of ENP2), with longitudinal row of outer spinules, with outer distal acute outgrowth, with one inner short seta; proximal part of ENP2 rectangular, distal extension cylindrical, 2.4 times as long as wide excluding distal cylindrical extension, with longitudinal row of outer spinules, with two inner setae arising from pedestal of which proximal (seta I on Fig. 18D) visibly shorter, subdistally with one strong inner and almost straight element (element III on Fig. 18D), with one lateral and one apical seta (setae IV and V on Fig. 18D) Fig. 18D).

P3
P4 (not shown). As in female. P5 (Fig. 18E). With outer seta of baseoendopod arising from setophore. Endopodal lobe reaching middle of exopod, with outer spinules as shown, with two distal modifi ed setae as shown of which outermost one shorter. Exopod triangular, 1.6 times as long as wide, with inner subdistal pore, with six setae -one proximal bipinnate seta, one medial and one subdistal short strong spines of which medial one shorter, one distal seta arising from setophore and two inner setae of which proximal one shorter. P6 (Fig. 17B). Asymmetrical, only one leg functional, each leg with three setae of which innermost one bipinnate, medial longest and bare, outermost shortest and bare.

Variability
Both caudal setae I spiniform in one female. One male possesses only one outer spine on P5 EXP. Bulbamphiascus Lang, 1944

Amended diagnosis
Miraciidae: Diosaccinae. Body fusiform. Rostrum not fused to cephalothorax, triangular, elongate, with rounded apical margin, almost as long as fi rst, second and third antennulary segments combined, with one subdistal sensilla on each side at third quarter of its length. Pro-and urosomites without extensions; with a fl exible unsclerotized cuticle between prosome and urosome. First urosomite (P5-bearing somite) narrower than preceding somites in dorsal view. Female genital double-somite (genital -second urosomite -and third urosomites fused) completely fused ventrally, with a dorsolateral cuticular rib marking former division between somites. Anal somite trapezoidal, without anal operculum. Caudal rami 1.6 times as wide as long in dorsal view, with seven setae. Female antennule eight-segmented, with aesthetasc and seta fused basally on fourth segment and with apical acrothek on last segment. Male antennule haplocer, 10-segmented, with aesthetasc and seta fused basally on fi fth segment, and with apical acrothek on last segment. Antennulary setae typically smooth. Antenna with allobasis and abexopodal seta; exopod threesegmented, armature formula 1-1-1,3,0. Mandibular palp biramous; endopod one-segmented, exopod two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites, proximal and middle endites with two, distal endite with three elements; ENP one-segmented. Maxilliped subchelate; (syn)coxa with four, basis with two setae, ENP one-segmented with claw and three accompanying setae. P1-P4 with three-segmented rami. Male P1 basis sexually dimorphic, with inner unipinnate spine and inner modifi ed accessory spine. P1 EXP shorter than ENP, reaching tip of ENP2; EXP2 with inner seta; ENP1 with inner seta; ENP3 longer than the ENP2, with one inner seta, a distal long and geniculate seta, and an outer spine. P2-P4 EXP and ENP of approximately the same length; P2-P4 EXP1 with inner seta; inner distal seta of EXP3 visibly shorter than other elements of same segment; P2 ENP2 with two setae, proximal shorter. Male P2 ENP sexually dimorphic, two-segmented; fi rst segment with one inner seta; second segment with two inner setae, one inner subdistal sigmoid element, one subdistal and one distal seta arising from cylindrical extension fused basally to segment, and one strong distal outer element strongly tapering distally. P5 EXP with six setae in female and male; one or two medial outer elements transformed into short spines. P5 endopodal lobe with fi ve setae in female, with two setae in male; armature of male P5 endopodal lobe strongly bipinnate.

Apomorphies for Bulbamphiascus
We did not detect any apomorphy for Bulbamphiascus. However, Bulbamphiascus is part of a larger monophyletic group composed of Spinodiosaccus gen. nov., Spinopedia gen. nov. and Pallarica gen. nov. (Fig. 19). The subdistal outer element of the male P2 ENP2 with almost parallel margins, viz slightly tapering distally, is considered here as part of the ground pattern of this monophyletic group and is regarded as a potential synapomorphy for this clade. The modifi cation of this spine into a strong tapering element is regarded here as secondary and is a synapomorphy for Bulbamphiascus and Spinodiosaccus gen. nov. The combination of an outer subdistal tapering spine and a sigmoid inner subdistal element on the male P2 ENP2 is unique to Bulbamphiascus (the outer subdistal spine on the male P2 ENP2 of Fig. 19. Strict consensus cladogram of the generic relationships within the Diosaccinae. Spinodiosaccus gen. nov. also tapers distally, but the inner subdistal element on the same segment of this species is rather straight).
Bulbamphiascus chappuisi is here relegated to incertae sedis due to the shape of the rostrum and furca, and to the morphology of the male P2 ENP, the illustrations of which (see Rouch 1962: 247, fi gs 29-33) are too schematic, preventing any further comparison.

Diagnosis
Miraciidae: Diosaccinae. Body fusiform; body surface seemingly covered with minute denticles. Rostrum not fused to cephalothorax, triangular, elongate, with round apical margin, almost as long as fi rst and second antennulary segments combined, with one subdistal sensilla on each side at third quarter of its length. Pro-and urosomites without extensions; with a fl exible unsclerotized cuticle between prosome and urosome. First urosomite (P5-bearing somite) narrower than preceding somites in dorsal view. Genital double-somite (genital -second urosomite -and third urosomites fused) completely fused ventrally, with a dorsolateral cuticular rib marking original division between genital and third urosomites. Telson trapezoidal, without anal operculum. Caudal rami short, about 1.5 times as wide as long in dorsal view, with seven setae. Female antennule eight-segmented, with aesthetasc and seta fused basally on fourth segment and with apical acrothek on last segment. Male antennule haplocer, 10-segmented, with aesthetasc and seta fused basally on fi fth segment and with apical acrothek on last segment. Setae of fi rst and second antennulary segments typically bipinnate, smooth in remaining segments. Antenna with allobasis and abexopodal seta; exopod three-segmented, armature formula 1-1-1,3,0. Mandibular palp biramous; endopod one-segmented, larger than exopod, the latter two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites, proximal and middle endites with two, distal endite with three elements; ENP one-segmented. Maxilliped subchelate; (syn)coxa with four, basis with two setae; ENP one-segmented, with claw and three accompanying setae. P1-P4 with three-segmented rami. Male P1 basis sexually dimorphic, with inner unipinnate spine and inner modifi ed accessory spine. P1 EXP shorter than ENP, reaching tip of ENP2; P1 ENP1 with strong bipinnate inner seta; P1 ENP3 2.5 times as long as ENP2, with one small inner seta, a distal long geniculate seta and one outer spine; P1 EXP2 with inner seta; P2-P4 EXP and ENP of approximately the same length. P2-P4 EXP1 with inner seta; inner distal seta of P2-P4 EXP3 visibly smaller than other inner setae on same segment. P2 ENP2 with two setae, proximalmost shorter. P2-P4 basis with inner chitinous projection. Male P2 ENP sexually dimorphic, two-segmented; fi rst segment with one inner seta; second segment completely covered by spinules and setules of diff erent lengths, with two inner setae subequal in length, two elements (one medial, one apical) issuing from elongate cylindrical extension fused to segment basally, and with one inner subdistal sigmoid blunt element and one outer subdistal blunt spine with almost parallel margins, viz slightly tapering distally, of which the former is shorter. P5 EXP longer than wide, comparatively shorter in male, with six setae in both sexes; two medial outer elements modifi ed into stiff short spines in male; distal outer spine foliaceous in female. P5 endopodal lobe with fi ve setae in female, with two setae in male; armature of male P5 endopodal lobe strongly bipinnate.

Etymology
The prefi x 'spino' from the Latin 'spīna', 'spine', and the sufi x 'pedia' from the Latin 'pēs', 'pedis', 'foot', refers to the presence of a spinular patch on the male P2 ENP1, and to the presence of several spinules and setules covering the male P2 ENP2. Gender feminine.

Apomorphies for Spinopedia gen. nov.
Two apomorphies for Spinopedia have been detected: i) presence of an inner subdistal spinular patch on the male P2 ENP1 and ii) male P2 ENP2 completely covered with spinules and setules of diff erent lengths. In addition, the subdistal inner seta of the female P5 EXP arises directly from the ramus (i.e., the seta does not arise from a setophore) (character 42 in Table 3 ; see also Fig. 19). The lack of a setophore for the subdistal inner seta of the female P5 EXP is regarded here as autapomorphic for the genus and is a result of reversal. The presence of a setophore for the inner subdistal seta of the female P5 EXP is autapomorphic for a larger group of genera to which Spinopedia gen. nov. belongs (Fig. 19) and seems to have evolved convergently in more than one evolutionary lineage within the Diosaccinae (Fig. 19).

Diagnosis
Miraciidae: Diosaccinae. Body fusiform. Rostrum not fused to cephalothorax, triangular, elongate, with round apical margin, almost as long as fi rst, second and third antennulary segments combined, with one subdistal sensilla at third quarter of its length, on each side. Pro-and urosomites without expansions. Genital double-somite (genital -second urosomite -and third urosomites fused) completely fused ventrally, with a dorsolateral cuticular rib marking original division between somites. Caudal rami about 1.5 times as wide as long in dorsal view; with seven setae. Female antennule eight-segmented, with aesthetasc and seta fused basally on fourth segment, and with apical acrothek on last segment. Antennulary setae typically smooth. Antenna with allobasis and abexopodal seta; exopod threesegmented, armature formula 1-1-1,3,0. Mandibular palp biramous; endopod one-segmented, larger than exopod, the latter two-segmented. Maxillule biramous; rami one-segmented. Maxilla with three endites, proximal and middle endites with two, distal endite with three elements; ENP two-segmented.
Maxilliped subchelate; (syn)coxa with three, basis with two setae; ENP one-segmented, with claw and three accompanying setae. P1-P4 with three-segmented rami. Male P1 basis sexually dimorphic, with inner unipinnate spine and inner modifi ed accessory spine. P1 EXP shorter than ENP, reaching tip of ENP2; P1 ENP1 with strong bipinnate inner seta; ENP3 2.5 times as long as ENP2, with one small inner seta, a long distal geniculate seta, and an outer spine; EXP2 with inner seta. P2-P4 EXP and ENP of approximately same lengths; P2-P4 EXP1 with inner seta; inner distal seta of P2-P4 EXP3 visibly shorter than other inner setae on same segment. P2 ENP2 with two setae, proximalmost small. Male P2 ENP sexually dimorphic, two-segmented; fi rst segment with one inner seta; second segment with two inner setae, two elements (one medial, one apical) issuing from elongate cylindrical extension fused to segment basally, and inner subdistal element almost straight and outer subdistal element slightly thicker and longer than the former and with almost parallel margins (i.e., slightly tapering distally). P5 EXP longer than wide in female, comparatively shorter in male, with six setae in female and seven setae in male; two medial outer elements stiff short spine-like in male, slender and smooth in female. P5 endopodal lobe with fi ve setae in female, with two setae in male; armature of male P5 endopodal lobe strongly bipinnate.

Etymology
This genus is dedicated to Rosa E. Pallares for her contribution to the taxonomy of harpacticoid copepods from Argentina. Gender feminine.

Apomorphies for Pallarica gen. nov.
This genus is unique by the possession of seven setae on the male P5 EXP, which is regarded here as apomorphic for the genus. The presence of an additional seta is regarded here as a character reversal.

Etymology
This genus is dedicated to Alain Dinet for his contribution to the taxonomy of harpacticoid copepods from France. Gender feminine.
The exclusion of Bulbamphiascus minutus from that genus and from any other genus presented here, and its reallocation into Dinetia gen. nov., is supported by, for example, the lack of the short inner distal seta on P2-P4 EXP3. Bulbamphiascus minutus probably bears a sister-group relationship with Pseudamphiascopsis Lang, 1944 andRhyncholagena Lang, 1944, with which it forms a monophyletic group (see Fig. 19). These three genera share the longer P1 ENP1 relative to the P1 EXP. Given that B. minutus could not be included in Bulbamphiascus or into any other diosaccin genus, and pending the discovery of the male of this species, we propose a new genus, Dinetia gen. nov., for B. minutus. The assessment and signifi cance of character 43 for D. minuta comb. nov. (see Table 3 ) is still pending until the male is described.

Typhlamphiascus medici sp. nov.
The highly complex taxonomy of Typhlamphiascus results from poor and incomplete original descriptions, in which the somatic spinular ornamentation was omitted and one or several appendages were not appropriately described, arguing that they resemble those of other congeners or species of somewhat related genera (for example, see Scott (1894) for T. accraensis; Thompson & Scott (1903) for T. gracilicaudatus; Por (1968) for T. latifurca; Scott (1902) and Sars (1911) for T. confusus confusus; Por (1963) for T. c. erythraeicus). This complexity is fuelled also by the high variability of some species (see Por (1963) and Lang (1965) for a discussion of T. c. confusus, T. c. erythraeicus and T. c. gullmaricus), but also by observational misinterpretations. This has led to a failure to detect potential (aut)apomorphies for the objective defi nition of the genus and its species.
In the last revision of Typhlamphiascus, Por (1963) proposed to subdivide the genus into two species groups based on the inner armature complement -total number of setae/spines -on P4 ENP3. Por (1963) defi ned his group I by the presence of two inner setae (fi ve elements in all) on the P4 ENP3 and his group II by the presence of one seta only (four elements in all) on the same segment. This criterion has been followed since and has proved to be useful for identifi cation purposes. Por also suggested that this group might be characterized by the female genital somite and third urosomite being separated only laterally, but fused dorsally and ventrally. We could not fi nd enough evidence for this, but the female genital and the third urosomites seem to be divided laterally only in T. gracilis (see Por 1963: 198; T. gracilicaudatus, see Por 1963: 199; T. bouligandi, see Soyer 1971: 275, fi g. 6a; T. drachi, see Soyer 1963a: 821, fi g. 1a). The condition of T. accraensis, T. blanchardi, T. capensis, T. dentipes and T. longifurcatus remains uncertain, and the genital and third urosomites are divided dorsolaterally in T. lutincola (see Soyer 1963b: 235, fi g. 1a). As for group II, the genital and third urosomites are divided dorsolaterally in most species, but this condition is inconclusive for T. brevicornis, and they seem to be divided laterally in T. lamellifer, T. typhloides and T. typhlops. The genital and third urosomites of T. latifurca were described as separated dorsally and ventrally (see Por 1968: 40-41, pl . 3 fi g. 13). This needs to be confi rmed.
Also, we observed that the female P5 EXP in Por's group I can be either normal or with the tip deformed into a hook-like process, and the inner spine of the P1 basis of the males can be either a normal, unmodifi ed spine or it can be modifi ed into an elongate, unornamented element with blunt tip, and that the P5 EXP of the females in Por's group II is always normal and the inner spine of the P1 basis of the males is always non-modifi ed. Also, in group I there seems to be a tendency towards the reduction of the apical setae on the female P5 endopodal lobe. This reduction is more pronounced in T. dentipes and T. blanchardi. A similar, though less pronounced tendency is observable also in T. ovale of group II.
Por's group I is currently composed of T. blanchardi, T. dentipes, T. gracilis, T. gracilicaudatus, and -probably -T. typhloides (Por 1963). Sars (1911: 391) noted that T. typhloides diff ers very little from T. confusus, and it most probably belongs to Por's group II. Group I also includes T. lutincola, T. drachi (Lang 1965), T. accraensis, T. l. capensis (Ma & Li 2017) and also T. longifurcatus. Ma & Li (2017) erroneously allocated T. longifurcatus to group II. The males of T. accraensis, T. l. capensis, T. blanchardi and T. dentipes remain unknown, but the inner spine on the male P1 basis is not modifi ed in the males of T. gracilicaudatus, T. gracilis or T. lutincola, but T. bouligandi, T. drachi and T. longifurcatus share a potentially synapomorphic modifi ed elongate inner spine on the P1 basis. The number of inner accessory spines (modifi ed spinules?) on the male P1 basis is highly variable within this group. Inner accessory spines on the male P1 basis are absent in T. bouligandi. Typhlamphiascus lutincola and T. drachi possess three inner accessory spines, T. gracilicaudatus displays from three to fi ve inner accessory spines and T. gracilis possesses from seven to eight inner accessory spines. The armature formulae of P1-P4 is constant throughout the entire group, but T. dentipes is unique and diff ers from T. blanchardi -with which it shares the modifi ed inner spine on the male P1 basis -and from the rest of the species of group I in the number of inner elements on the P4 EXP3 (with three setae in T. dentipes, but with two setae in T. blanchardi and in the rest of the species of group I). The armature complement of the male and female P5 endopodal lobe is fairly constant within group I (fi ve setae in the females except for the female of T. gracilicaudatus with four setae; two setae in the males), but the number of setae on the male and female EXP varies from four (as in the males of T. gracilicaudatus and T. bouligandi, and in the female and male of T. longifurcatus), to fi ve (as in the females of T. gracilicaudatus and T. dentipes, and in the males and females of T. gracilis and T. drachi), and six (as in the females of T. accraensis, T. l. capensis and T. bouligandi, and in the male and female of T. lutincola). The supranumerary armature complements of the female P5 EXP of T. blanchardi (eight elements), as reported by Scott & Scott (1895), is most probably erroneous. Also, the shape of the female P5 EXP is rather constant within group I and within the genus, but T. blanchardi and T. dentipes share having the tip of the female P5 EXP modifi ed into a hook-like process, as well as a marked tendency towards the reduction of the apical setae of the female P5 endopodal lobe. These two characters could constitute potential synapomorphies for these two species.
Por's group II is currently composed of T. higginsi, T. brevicornis, T. c. confusus, T. c. erythraeicus, T. c. gullmaricus, T. l. lamellifer, T. latifurca, T. ovale, T. pectinifer, T. tuerkayi, T. typhloides, T. typhlops, T. unisetosus and T. medici sp. nov. Kunz (1975) described a new subspecies of T. l. lamellifer, T. l. capensis from South Africa, without any justifi cation for attributing the latter to this species. Typhlamphiascus l. lamellifer possesses one seta only on the P4 ENP3 (Por's group II), but two setae are present on the same segment in T. l. capensis (Por's group I). The armature complement of the P4 ENP3 has been consistently used to separate Por's groups I and II. In our opinion, the diff erences between these two taxa are beyond the diff erences that could be expected between a nominotypical species and its subspecies, and T. l. capensis probably represents a diff erent species. Thus, we propose to consider T. l. lamellifer and T. l. capensis as distinct species and to give the latter full species rank as T. capensis Kunz, 1975 comb. nov. The inner spine on the male P1 basis is not modifi ed in all the species and subspecies of this group; the males of T. unisetosus and T. brevicornis remain unknown, but the number of inner accessory spines on the male P1 basis is highly variable. Typhlamphiascus lamellifer possesses two inner accessory spines; T. higginsi, T. latifurca, T. pectinifer and T. medici sp. nov. possess three inner accessory spines; from three to fi ve inner accessory spines can be found in T. c. confusus; T. c. erythraeicus possesses four inner accessory spines; T. c. gullmaricus possesses from fi ve to seven inner accessory spines; T. ovale and T. tuerkayi possess eight inner accessory spines. The number of inner accessory spines seems to be highly variable in T. typhlops. Sars (1906b) described four inner accessory spines on the male P1 basis of this species, but Por (1963) and Chislenko (1967) reported from seven to eight inner accessory spines. The armature complements of P1-P4 are fairly constant in the species of group II, and only three species -T. higginsi, T. unisetosus, and T. typhlops -deviate from the most common armature formulae of P1-P4 EXP/ENP (P1: 0-0-0,2,3 / 1-1-1,1,1; P2: 1-1-1,2,3 / 1-2-1,2,1; P3: 1-1-1,2,3 / 1-1-2,2,1; P4: 1-1-2,2,3 / 1-1-1,2,1). Typhlamphiascus typhlops seems to occupy an isolated position given the lack of inner armature on P4 ENP2 (armature formula 1-0-1,2,1). Interestingly, Por (1963) had the opportunity to inspect two samples of T. typhlops in Lang's collection and observed the presence of an inner seta on P4 ENP2. Por considered this as the true condition for the P4 ENP2 of T. typhlops. Kunz (1975) described the P4 ENP2 of T. capensis comb. nov. without inner seta, but he suggested that this seta might have become detached from the supporting segment as indicated by the interrupted cuticle in the place where the inner seta might once have been, and suggested that the lack of this seta might be of little importance. Typhlamphiascus higginsi and T. unisetosus share the reduced inner armature complement of P3 ENP3 from two to one seta. Additionally, T. higginsi is unique within the genus by its lack of inner armature on the P2-P3 EXP3. The armature complements of the female P5 EXP and endopodal lobe (six and fi ve setae, respectively) are constant in group II, and only one species, T. tuerkayi, possesses four setae on the endopodal lobe. The armature complement of the male P5 endopodal lobe is constant throughout the genus (with two bifurcate setae); not so the armature complements of the P5 EXP, which varies from four setae in T. tuerkayi, to fi ve elements as in T. latifurca, and six as in T. higginsi, T. c. confusus, T. lamellifer, T. ovale, T. medici sp. nov. and T. pectinifer (males of T. unisetosus and T. brevicornis unknown). Noteworthy, T. lutincola of Por's group I, and T. pectinifer and T. medici sp. nov. of group II are unique within the genus in that they share a bifurcated innermost seta on the male P5 EXP. The bifurcated innermost seta on the male P5 EXP in T. pectinifer -known from Monterrey Bay (California, USA) (Lang 1965) and Tierra del Fuego (Argentina) (Pallares 1975) -and in T. medici sp. nov., but also in T. lutincola, known from the French Mediterranean (Soyer 1963a), could constitute a potential synapomorphy for these three species.
To the best of our knowledge, the last diagnosis of the genus Typhlamphiascus was presented by Lang (1948: 705). The genus has been defi ned subjectively on a combination of features and no apomorphies have been detected for the genus, nor have any synapomorphy been found to unite all its species objectively, and the relationships between the species of Typhlamphiascus have been based on morphological similarities only. Chullasorn (2009: 506) gave a list of autapomorphies for T. higginsi. These are: (i) male P1 basis with three inner accessory spines, (ii) reduced number of setae/spines on P3 ENP3 from fi ve to four, (iii) reduced number of setae/spines on P4 ENP3 from fi ve to four, (iv) P1 EXP1 reaching tip of ENP2, (v) caudal rami two times as long as wide, (vi) seven minute spinules on each side of the female genital somite, (v) fourth and fi fth female urosomites with posterior spinular row ventrally and (vi) caudal rami twice as long as wide, with two small spinules at the base of caudal seta VII. In our opinion, these are not true autapomorphies for T. higginsi, since all of them are shared by one or more species within the genus. For example, the presence of three inner accessory spines on the male P1 basis is shared by a larger set of species (T. gracilicaudatus, T. lutincola, T. drachi, T. c. confusus, T. latifurca, T. pectinifer and T. medici sp. nov.), the reduced number of setae/spines on P3 ENP3 from fi ve to four is also present in T. unisetosus and the reduced number of setae/spines on P4 ENP3 from fi ve to four is present in all the species of Por's group II. The only potential (aut)apomorphy that we could detect for T. higginsi is the loss of the inner armature on P2-P3 EXP3. In her description of the maxilliped of T. higginsi, Chullasorn (2009) confused the basis with the syncoxa, a fi rst endopodal segment with the basis, and a second endopodal segment with the one-segmented endopod. She also reversed P1 and P2, as well as P3 and P4 in her fi gures (Chullasorn 2009: 498, fi g.3 and 499, fi g. 4, respectively). Also, her fi gures of the ventral and dorsal views of the urosome of T. higginsi (Chullasorn 2009: 500, fi g. 5a-b) are reversed, and so are the male maxilliped and maxilla (Chullasorn 2009: 502, fi g. 7).
In their description of Typhlamphiascus tuerkayi, Ma & Li (2017) suggested a close relationship between their species and both T. ovale and T. higginsi based on (i) the presence of ventral hyaline frills on the posterior edge of the posterior half of the genital double-somite, and fourth and fi fth urosomites, (ii) presence of one inner seta on P1-P4 EXP2, (iii) presence of an inner seta on P2-P4 EXP1, (iv) presence of one inner seta on P1-P4 ENP1, (v) P1 ENP3 with three setae, (vi) female P2 ENP2 with two inner setae, (vii) female P5 EXP with six setae and (viii) endopodal lobe of the male P5 with two bifi d elements. However, all these features are common to the whole genus and are not indicative of a close relationship between T. tuerkayi on one hand and T. ovale and T. higginsi on the other. Also, Ma & Li (2017) described the mandibular endopod as two-segmented -fi rst segment with one, second segment with two setae -but on their fi gure (Ma & Li 2017: 994, fi g. 2d) the mandibular exopod appears as one-segmented with two setae.
Briefl y, given the complex taxonomy of the genus and the lack of potential (syn)apomorphies, any hypothesis on the phylogenetic relationships of the species of Typhlamphiascus is at this moment futile and an in-depth revision of the genus is needed. At this point it seems that (i) Por's criterion (Por 1963) to subdivide the genus into two species groups on the armature complement of the P4 ENP3 is probably useful for identifi cation purposes only, (ii) that some species seem to be related by the shape of the female P5 EXP and shape of the apical elements on the female P5 endopodal lobe (T. blanchardi and T. dentipes), the sexually dimorphic inner spine of the male P1 basis (T. bouligandi, T. drachi and T. longifurcatus), the presence of a bifurcated inner element on the male P5 EXP (T. lutincola, T. pectinifer and T. medici sp. nov.) and the reduced armature of the P3 ENP3 from fi ve to four (T. higginsi and T. unisetosus) and (iii) that the only species with a potential (aut)apomorphy (without inner armature on P2 EXP3) is T. higginsi (see Tables 1-2 ).
Typhlamphiascus medici sp. nov. belongs to Por's group II. The new species proposed herein share the armature complements of the female P1-P5 with all species of group II except for T. typhlops (without inner seta on P4 ENP2; but see above), T. unisetosus (with only one inner seta on P3 ENP3), T higginsi (with only one inner seta on P3 ENP3 and without inner armature on P2-P3 EXP3) and T. tuerkayi (with only four setae on the P5 endopodal lobe). The males of T. unisetosus and T. brevicornis remain unknown and the males of some other species have been described incompletely. The male antennules of the species for which these appendages have been described have been shown to be nine-segmented, and only T higginsi and T. medici sp. nov. were described with eight-and ten-segmented male antennules, respectively. The nine-segmented condition of the male antennule in T. ovale, T. pectinifer and T. tuerkayi is most probably the result of a failure to detect the separate third and fourth segments which are common in podogennontan harpacticoids (Willen 2000). Similarly, the eight-segmented condition of the male antennule of T. higginsi is most probably the result of a failure to detect the separated third and fourth segments, but also the sixth segment. The latter seems to be incorporated into the fi fth segment in Chullasorn (2009: 502, fi g. 7a) and requires confi rmation. In our opinion it is highly probable that all species of Typhlamphiascus possess ten-segmented male antennules, as shown for T. medici sp. nov. The setation pattern of the male P5 endopodal lobe with two bifurcate setae is constant throughout the genus and group II; not so the armature complements of the exopod which varies in group II from four (T. tuerkayi) to fi ve (T. latifurca) and six setae (T. higginsi, T. confusus, T. lamellifer, T. ovale, T, pectinifer, T. medici sp. nov. and T. typhlops). As noted above, T. pectinifer, T. medici sp. nov. and T. lutincola share the bifurcated innermost seta of the male P5 EXP. The number of inner accessory spines on the male P1 basis is variable in T. c. confusus (from three to fi ve), T. c. gullmaricus (from fi ve to seven) and T. typhlops (four inner accessory spines were observed by Sars 1906a, but from seven to eight by Por 1963 andChislenko 1967). Four inner accessory spines have been reported in T. c. erythraeicus, and only two were observed in T. lamellifer. Typhlamphiascus medici sp. nov., T. higginsi, T. latifurca and T. pectinifer share the presence of three inner accessory spines on the male P1 basis. Typhlamphiascus medici sp. nov. is more similar to and probably bears a close relationship with T. pectinifer and T. lutincola, as suggested by the bifurcated condition of the inner distal bifurcate seta on the male P5 EXP. Besides the armature complement of P1-P5, the male armature complements of the male P5 and the bifurcate inner seta on the P5 male EXP, T. pectinifer and T. medici sp. nov. are unique also in the combination of having three inner accessory spines on the male P1 basis and six setae on the male P5 EXP. The Mexican material could be attributed to a new subspecies of T. pectinifer. Besides the features shared by these two species, this reasoning might fi nd support also in their distribution. Typhlamphiascus pectinifer was described from Monterey Bay, central California, USA, about 2000 km from the type locality of T. medici sp. nov. in the mouth of the Gulf of California. Typhlamphiascus pectinifer was also reported from Tierra del Fuego, Argentina (Pallares 1975). Pallares' material fi ts Lang's description (Lang 1965), including the ventral spinular ornamentation of the last urosomites, but a more detailed examination of the South American population would be necessary to confi rm its identity. A scenario where the original population from the Central Eastern Pacifi c split and gave birth to two diff erent species through vicariance is feasible. The latter view is grounded in some diff erences to support the presence of two related species. These are: (i) subdistal inner ornamentation of caudal rami (with a row of spinules forming a comb in T. pectinifer, but with very few spinules in the Mexican species), (ii) dorsolateral spinular ornamentation of both halves of the genital double-somite, and fourth urosomite in the female, and of the genital, third and fourth urosomites in the male (without dorsolateral spinular ornamentation in T. pectinifer, but with some spinules in T. medici sp. nov.), (iii) relative length of the caudal setae (comparatively shorter in T. pectinifer), (iv) relative length of the two innermost setae of the female P6 (visibly longer in the Mexican material), (v) number of midventral spinules on the female fourth urosomite (with fi ve spinules in Lang's species, but with 13 spinules in T. medici sp. nov.), (vi) number of midventral spinules on the female and male fi fth urosomite (a continuous row of spinules in T. pectinifer, but with only six spinules in T. medici sp. nov.), (vii) relative length of the outer proximal seta of the female P5 EXP (relatively longer in the new species), (viii) relative length of the inner setae on the female P2 ENP2 (short and subequal in length in T. pectinifer, but subdistal seta visibly longer than proximal element in the Mexican species), (ix) relative length of the inner setae on the male P2 ENP2 (visibly shorter in T. pectinifer) and (x) probably the shape of the innermost element of the male P6 (seemingly setiform in T. pectinifer, but spiniform in the new species). The two large tube pores observed in the fi rst and second antennulary segments in females and males of the new species have not been observed before. The presence of this pair of tube pores is deemed to be a potential apomorphy for the species, but its absence in other species still needs confi rmation.
Our analyses showed Typhlamphiascus as the fi rst off shoot of the Typhlamphiascus-Spinodiosaccus gen. nov. monophylum, before the acquisition of characters 24 and 26 (P2 and P3 EXP3 with short distal seta on the inner margin) which support the monophylum Monardius-Spinodiosaccus gen. nov.
Phylogenetic position of Dinetia gen. nov., Pallarica gen. nov., Spinopedia gen. nov., Spinodiosaccus gen. nov. and Bulbamphiascus The complete clarifi cation of the phylogenetic affi nities within the Diosaccinae is far beyond the scope of this study. A more exhaustive analysis of a more complete data set including more characters (i.e., structure and setation of mouth parts, armature number and shape of swimming legs, homology of the inner armature of the male P1 basis and of the male P2 ENP) and as many species as possible would be necessary. Instead, our main objective was to test the monophyletic status of the genus Bulbamphiascus as defi ned by Mu & Gee (2000). To accomplish this, and considering the high level of character convergence within the Diosaccinae (which probably fostered the establishment of nonmonophyletic genera based solely on the setal formulae of P1-P5), we included species of all genera, but restricted our analyses to the type species of the non-monophyletic genera. Our results on the phylogeny within the Diosaccinae are preliminary -its phylogeny is not fully resolved -but they refl ect the phylogenetic relationships between Bulbamphiascus and the newly proposed genera. Given the preliminary nature of our results, the characters considered will not be discussed in detail. Instead, we will focus on the characters that contribute to the monophyletic status of i) a clade composed of Dinetia gen. nov., Pseudamphiascopsis and Rhyncholagena and ii) a clade composed of Pallarica gen. nov., Spinopedia gen. nov., Bulbamphiascus and Spinodiosaccus gen. nov.
The genus Bulbamphiascus was originally proposed by Lang (1944) and was defi ned as diff erent from Amphiascus and other diosaccin genera primarily on the structure of the PI endopod, the setal formula of P2-P5, and the usually bulbous shape of the distal outer seta on the P5 EXP (Mu & Gee 2000). They (Mu & Gee 2000) gave a brief historical account of the genus and off ered an amended diagnosis, in which they included some characters that we consider important synapomorphies for a more inclusive group of genera related to Bulbamphiascus, i.e., distal inner seta of P2-P4 EXP3 weakly developed (characters 24, 26, 28 in the present study; Table 3 , Fig. 19), and P5 with medial and distal outer spines -sometimes -swollen at its base (or short and blunt) (characters 38 and 39 in the present study; Table 3, Fig. 19). Character 28 is a unique synapomorphy for a monophyletic clade represented by Robertsonia, Amphiascus, Pararobertsonia, Sinamphiascus, Pallarica gen. nov., Spinopedia gen. nov., Bulbamphiascus and Spinodiosaccus gen. nov. Characters 24 and 26 (see Table 3 , Fig. 19) place Monardius and Tydemanella as the sister group of a clade supported by character 28 which seems to have appeared convergently also in Sarsamphiascus, the latter with an uncertain phylogenetic affi nity European Journal of Taxonomy 759: 1-62 (2021) 54 with other groups. The original description of the type of Sarsamphiascus, S. minutus (Claus, 1863), is too incomplete, and Sars (1906a) omitted the P3. The male P2 ENP2 of S. minutus as illustrated by Sars (1906a: pl. 96) resembles that of Pallarica gen. nov. and Spinopedia gen. nov. in that the inner subdistal spine is blunt and only slightly sigmoid, and the outer subdistal spine is blunt and tapers slightly distally.
The diagnosis of Bulbamphiascus by Mu & Gee (2000) and our own results indicate that the medial and subdistal outer elements of the female and male P5 EXP being reduced to short and basally bulbous elements is the only potential autapomorphy for the genus. This assumption lead to an alternative scenario where the new species attributed here to Spinodiosaccus gen. nov. would actually be a derived form of Bulbamphiascus, and the loss of the inner seta of P1 EXP2 and the inner seta of P2-P4 EXP1 should be interpreted as a secondary loss. However, in light of current research and upon re-diagnosis of Bulbamphiascus, the morphological homogeneity within this genus points towards a scenario in which Spinodiosaccus gen. nov. appears as an early off shoot of the Bulbamphiascus-Spinodiosaccus lineage. On the other hand, given the poor and sketchy descriptions of most species, it is diffi cult to detect any autapomorphy for Bulbamphiascus. Although we have not coded any character for the male P2 ENP2, the combination of the outer subdistal tapering spine and the inner subdistal sigmoid element in the male P2 ENP2 in Bulbamphiascus is regarded here as a potential apomorphy for that genus. Following this line of reasoning, Spinodiosaccus gen. nov. is defi ned by the presence of six autapomorphic character states: i) male antennule 11-segmented (character 2 in Table 3 , Fig. 19), a unique reversion within the Diosaccinae, ii) loss of the inner seta of P1 EXP2 (character 6 in Table 3 , Fig. 19), iii) loss of the inner seta of P2 EXP1 (character 14 in Table 3 , Fig. 19), iv) loss of the inner seta of P3 EXP1 (character 15 in Table 2 , Fig. 19), v) loss of the inner seta of P4 EXP1 (character 16 in Table 3, Fig. 19) and vi) absence of an anterior tube pore on the male P3 EXP3 (character 31 in Table 3 , Fig.19). Also, character 28 (presence of a short distal inner seta on P4 EXP3) is a potential synapomorphy for, at least, Amphiascus, Pararobertsonia, Sinamphiascus, Pallarica gen. nov., Spinopedia gen. nov., Bulbamphiascus and Spinodiosaccus gen nov. Characters 14-16 appeared convergently within the monophyletic clade Amonardia-Psammotopa (see Fig. 19). Similarly, character 6 appeared convergently in the sub-clade Pholenota-Psammotpoa and in the clade Antiboreodiosaccus-Pseudodiosaccus. The anterior tube pore on the male P3 EXP3 occurs convergently in many diff erent genera within Diosaccinae, namely Amphiascus, Amphiascoides, Bulbamphiascus (Mu & Gee 2000), Haloschizopera (Gee & Fleeger 1990), Paramphiascella, Robertgurneya, Rhyncholagena, Sinamphiascus (Nam & Lee 2012), Spinopedia gen. nov. and Typhlamphiascus. The condition within Robertsonia, Pararobertsonia and Pallarica gen. nov. must be re-investigated, since such structures as tube pores were frequently neglected in older descriptions.
Interestingly, the largest monophylum in which Bulbamphiascus and allied genera are included is supported only in the total consensus cladogram by the reversion of character 12 (see Table 3 ) -P1 ENP1 shorter or slightly longer than EXP. The plesiomorphic condition where the P1 EXP is considerably shorter than ENP1 is shared in all remaining genera of Diosaccinae. In the total consensus cladogram, the reversion of character 12 also appears as an independent evolution in the clade Antiboreodiosaccus-Pseudodiosaccus, which is also characterised by the reversion of characters 41 and 43, which also supports the monophyletic status of the clade Amonardia-Psammotopa. This clearly separates these monophyletic clades from the large monophylum containing Typhlamphiascus-Spinodiosaccus gen. nov. However, Antiboreodiosaccus-Pseudodiosaccus does not appear as closely related to Amonardia-Psammotopa in any of the 12 most parsimonious trees (see Supplementary File 1). This renders the synapomorphic condition of character 12 but also of characters 41 and 43 unclear, and the topology and optimization in Fig. 19 would be an artefact of the total consensus algorithm.
Bulbamphiascus cibimae is unique within the Diosaccinae by the male P5 EXP having seven setae (character 35 in Table 3 ). The medial and subdistal outer elements of the male P5 EXP of B. cibimae display some degree of reduction in size but are not spine-like blunt and are not swollen basally as in other species of the genus. This justifi es the exclusion of B. cibimae from Bulbamphiascus and its reallocation in a new genus, Pallarica gen. nov. as P. cibimae comb. nov., also characterized by the apomorphic reduction in length of the medial and subdistal seta of the male P5 EXP. On the other hand, the reduced medial and subdistal outer spines of the male P5 EXP is regarded here as synapomorphic for Pallarica gen. nov., Spinopedia gen. nov., Bulbamphiascus and Spinodiosaccus gen. nov. These four genera also share the same morphology of the armature of the A2 EXP3, i.e., with one distal seta, one spine and a longer spiniform element (character 3 in Table 3 ). Character 3 is also shared with Sinamphiascus and indicates that this genus should be included in this clade as the most basal taxon. The male P2 ENP2 is very similar in Pallarica gen. nov. and Spinopedia gen. nov.
The establishment of Spinopedia gen. nov. is clearly supported by the spinular ornamentation on the male P2 ENP1 and ENP2. In addition, the second inner seta from inner to outer margin of the female P5 EXP does not arise from a setophore but inserts directly on the inner edge of the ramus. Spinopedia gen. nov. bears a sister-group relationship with Bulbamphiascus and Spinodiosaccus gen. nov., as indicated by the reduction of the subdistal outer element of the male P5 EXP into a short, bare spine-like element, but Spinodiosaccus gen. nov. diff ers from Bulbamphiascus and Spinopedia gen. nov. in the well-developed subdistal outer seta of the female P5 EXP.
Among all the genera proposed here, Dinetia gen. nov. is the only one that does not belong to the same larger monophyletic clade Pallarica-Spinodiosaccus. Dinetia gen. nov. cannot be included within any of the remaining clades either. In fact, it seems closely related to Pseudamphiascopsis and Rhyncholagena, with uncertain phylogenetic affi nities with the remaining monophyla. The male of Dinetia gen. nov. remains unknown and the supposed apomorphic status of character 43 (see Table 3 ) for this genus -which was coded as '?' -is rather the result of the program's algorithm used in this study for the phylogenetic analysis. The same happens for the supposed synapomorphic status of character 34 -male P5 EXP with fi ve spines -for Dinetia gen. nov., Pseudamphiascopsis and Rhyncholagena, and character 11 -P1 ENP3 elongate, at least 1.5 times as long as ENP2 -is the only synapomorphy for this group of genera. However, it is not clear whether the Dinetia-Rhyncholagena clade is a true monophyletic clade or if these genera are clumped together by convergent characters. Bulbamphiascus minutus, the type species of Dinetia gen. nov., does not share important diagnostic characters with Bulbamphiascus, e.g., presence of a short inner distal seta on P2-P4 EXP3, and cannot be included in the latter. Dinet (1971) expressed some doubts about the membership of B. minutus in that genus and suggested some affi nities with Typhlamphiascus. He placed his newly described species in Bulbamphiascus based on superfi cial similarities of the P5 and relative length of the caudal rami, and the general shape of the antennule, antenna and maxilliped. However, as recognized by Dinet (1971), B. minutus lacks the bulbous setae on the female P5 EXP. Also, the general shape of the female antennule is common to the Diosaccinae, Dinet's descriptions of the mouth parts are too sketchy to allow further comparisons (see Dinet 1971), and the caudal rami of B. minutus are longer than in other species of Bulbamphiascus except for B. chappuisi, which is relegated here as species incertae sedis, and taper distally.
Our results show that most genera are arranged into three large monophyletic groups -Antiboreodiosaccus-Pseudodiosaccus, Typhlamphiascus-Spinodiosaccus and Amonardia-Psammotopa -the remaining groups being less speciose and of unclear phylogenetic affi nities. The Amonardia-Psammotopa clade can easily be identifi ed by the male P5 EXP having four or fi ve setae (but three in Psammotopa). The remaining characters showed reversal along the topology in an almost haphazard manner. The Typhlamphiascus-Spinodiosaccus clade can easily be characterized by having the P1 ENP1 at most slightly longer than EXP (character 12); this character seems to have evolved convergently in the Antiboreodiosaccus-Pseudodiosaccus clade as well as in Balucopsylla-Helmutkunzia, Protopsammotopa, but also in Psammotopa. The Typhlamphiascus-Spinodiosaccus clade is also characterized by the presence of a middle inner seta of the female P5 EXP issuing from a setophore (character 42 in Table 3 ); this character evolved independently in Paramphiascella, Robertgurneya, Schizoperoides, Pseudamphiascopsis and Rhyncholagena. Interestingly, the clade Monardius-Spinodiosaccus is unique in the -synapomorphicpresence of a short distal inner seta on the P2-P3 EXP3.
Although not recovered in our analyses, the Antiboreodiosaccus-Pseudodiosaccus clade could be basal to the Amonardia-Psammotopa clade. These two clades share character 43 (the middle -or the third seta from inner to outer margin -of the female P5 EXP not issuing from a setophore and arising directly from the ramus; a character reversion within the Diosaccinae). The loss of the inner armature of the P1 EXP2 (character 6 in Table 3) in the Antiboreodiosaccus-Pseudodiosaccus clade and at the base of the Amonardia-Psammotopa clade (in Pholenota-Psammotopa) is a potential piece of evidence for merging them.
Briefl y, our preliminary data support the split of Bulbamphiascus into diff erent genera, clearly showing that Dinetia gen. nov. does not belong to the Typhlamphiascus-Spinodiosaccus monophyletic clade. Our data also show that the Diosaccinae are divided into at least two large monophyletic units, but more work is needed to prove the monophyly of several genera and their phylogenetic relationships.

Ecology
Typhlamphiascus medici sp. nov. and S. primus gen. et sp. nov. were present at sampling stations 2, 4, 5, 7 and 10, and S. primus gen. et sp. nov. was also recorded at station 9 ( Table 5 , Fig. 20). Spearman's correlation coeffi cient (p ≤ 0.05) revealed a strong positive correlation between the density of both T. medici sp. nov. and S. primus gen. et sp. nov., and sand and dissolved oxygen (see also Table 6 for environmental variables). Similarly, Spearman's correlation coeffi cient showed a strong negative correlation between the density of these two species and silt and clay contents (Tables 7-8 ).
The non-parametric analysis of variance revealed statistical diff erences (F = 5.09, p < 0.05) in the density values of T. medici sp. nov. and S. primus gen. et sp. nov. between stations along the Urías system.
The PCoA (Fig. 21) showed that principal component 1 (PCO1) accounts for 55.6% of total variation and principal component 2 (PCO2) explains 26% of total variation. Stations 1, 7 and 8 with silty sediments and station 3 with comparatively coarser sediments are considered as atypical due to the absence of both T. medici sp. nov. and S. primus gen. et sp. nov. Stations 2, 4, 5, 6 and 10 are 77% similar in terms of mean density of both species, and station 9 is excluded from this group due to the absence of T. medici sp. nov. Stations 5 and 6 are 90% similar, as are stations 4 and 10 in terms of mean density of both species. Station 2 seems to be diff erent from all the other stations where T. medici sp. nov. and S. primus gen. et sp. nov. were found. On the other hand, higher mean density values of T. medici sp. nov. and S. primus gen. et sp. nov. were recorded at stations characterized by well-oxygenated sandy sediments at the shallower upper and middle-upper region of the Urías system with comparatively higher salinity values (stations 2, 5, 4 and 6). Comparatively lower mean density values of these two species were recorded at the comparatively deeper station 10 with sandy sediments, where a comparatively lower salinity and dissolved oxygen values were also observed. Typhlamphiascus medici sp. nov. was not found at station 9, where only S. primus gen. et sp. nov. was present. See Gómez (2020a: 43, fi g. 1) for a map with the location of the sampling stations.
Briefl y, grain size and dissolved oxygen content are the main proxies for the distribution of T. medici sp. nov. and S. primus gen. et sp. nov. in the Urías system. High levels of organic matter content and low levels of dissolved oxygen are commonly associated with muddy sediments and are likely important factors for the distribution of these two species. Morales-Serna et al. (2006) showed similar results in their study on the spatial and temporal variation of species richness of benthic copepods from the same area. The analysis of the distribution of these two species and of the rest of the harpacticoids collected