Two new species in the family Axinellidae (Porifera, Demospongiae) from British Columbia and adjacent waters

Abstract Two new species of Demospongiae are described for British Columbia and adjacent waters in the family Axinellidae, Auletta krautteri sp. n. and Dragmacidon kishinensis sp. n. They represent range extensions for both of these genera. Both are fairly commonly encountered, Auletta krautteri below diving depths (87 to at least 300 m) and Dragmacidon kishinensis in shallow water (intertidal to 30 m). We propose an amended genus diagnosis for Auletta to account for the variability among species in principal spicules that form the ascending tracts to be either oxeas, styles or strongyles rather than just oxeas.


Introduction
A brief history of surveys and publications from 1878 to 1966 including sponges in British Columbia is presented in Austin et al. (in prep.). Of the approximately 200 demosponge species recorded for this region (Austin 1985, Austin et al. 2012, six species were regarded as members of the family Axinellidae (Austin 1985, Austin andOtt 1987). Three of these have now been removed from this family. Syringella amphispicula de Laubenfels, 1961 was recently shown to belong to the genus Homaxinella and hence to the family Suberitidae (Austin et al. in prep). Stylissa stipitata de Laubenfels, 1961 is not a Stylissa and not an axinellid; It is considered to be a synonym of Semisuberites cribrosa (Micklucho-Maclay, 1870) by van Soest et al. (2012). Specimens identified by us as Phakettia sp. aff. beringensis we now consider to be Semisuberites cribrosa. Finally, a specimen identified as Axinella sp. has been lost. We defer any formal description until we have more material. It has been seen twice from a submersible at 100 m. The remaining two species, both new, are described in this paper: Auletta krautteri sp. n. and Dragmacidon kishinensis sp. n. Alvarez and Hooper (2002) provided a discussion of the history, definition and scope of the Axinellidae. They reviewed the literature and concluded that among 92 nominal genera, only 10 were valid (Auletta, Axinella, Cymbastela, Dragmacidon, Dragmaxia, Pararhaphoxya, Phakellia, Phycopsis, Ptilocaulis, and Reniochalina).

Materials and methods
Specimens housed in the Khoyatan Marine Laboratory museum (KML) were largely preserved and maintained in 70% isopropyl alcohol; some are dried. KML specimens were collected either by hand in the intertidal, by SCUBA in the shallow subtidal, or by dredge, submersible (PISCES IV, DELTA) or ROV (ROPOS) in deeper water.
Collections were examined for axinellids from the NE Pacific at Royal BC Museum, California Academy of Sciences, and the Canadian Museum of Nature. In some cases material was brought back to KML for more detailed study.
Under material examined, for each lot we report: institution accession number, station number, location, latitude and longitude, depth, date of collection, collector, and number of specimens. Where geographic location but not latitude and longitude was recorded, we include them following the abbreviation for approximate: ca.. We endeavoured to track down missing data but were not always successful. Sources for obtaining geographic coordinates include: Google Earth, Sailing directions BC Coast (North & South Portion), United States Coast Pilots: Pacific Coast #8, southern Alaska, and #7, BC Geographical Names Information System, and Canadian Hydrographic Service charts.
Where colour photographs were taken, in situ scale bars are approximate. Photos taken together with specimens are assigned the same station number and accession number as those specimens.
Thick sections of specimens were made by excising approx. one cm 3 surface blocks, dehydrating in ethanol and embedding these in 68°C melting point his-tological paraffin. After cooling to room temperature, the blocks were trimmed to either vertical or tangential orientation and re-warmed to 40°C for one hour to prevent cracking during sectioning. Warmed tissue blocks were set into a guiding jig and sectioned by hand with a straight razor at varied, but only marginally controllable thicknesses of between 0.1 and 1.0 mm. The best sections were de-paraffinized in xylene and mounted on microscope slides in Canada balsam for observation, measurement and photography.
Tissue-free spicule preparations were made by dissolving small pieces of sponge in sodium hypochlorite. For each spicule type we measured, using a compound microscope, the diameter or length and width of 50 spicules (unless noted otherwise by N=). We scanned microscope fields for spicules of variable sizes, but ignored obviously ontogenetically young spicules in determining size ranges. We list spicule dimensions as three numbers, the minimum, mean and maximum, e.g., 200-(250)-300. All measurements are in micrometers (μm). For scanning electron microscopy (SEM), cleaned spicules were either deposited onto membrane filters that were then taped to stubs, or deposited directly on double-sided tape attached to stubs. Preparations were coated with gold-palladium and viewed either in a Hitachi S-3500N SEM at the University of Victoria, or in one case an ETEC Biosem at Simon Fraser University.
Holotypes have been deposited in the Royal British Columbia Museum, Victoria, BC, Canada and paratypes have been deposited in the Canadian Museum of Nature, Ottawa, Ontario.
Taxa including families, genera and species are arranged alphabetically. Systematic hierarchy follows Hooper and . Abbreviations used in the text ordered alphabetically are: approx.=approximate; BC=British Columbia; CASIZ=California Genus diagnosis. Tubular, erect on peduncle or narrow base. Surface smooth or tuberculated with choanosomal spicules projecting slightly; ectosome without specialised skeleton. Choanosomal skeleton plumoreticulate, with longitudinally strongyle or sinuous oxea tracts, connected by single styles or plumose tracts of styles; masses of sinuous strongyles reinforcing the stem and may reinforce the inner tube wall. Megascleres sinuous strongyles or oxeas, always coring main spicule tracts and inner tube walls; styles and or oxeas, plumo-echinating and connecting main tracts. Microscleres absent.
(Amended from Alvarez and Hooper 2002) Auletta krautteri sp. n. http://zoobank.org/B1D4806D-AE5D-4D4E-8DDC-6B5E2685BB76 http://species-id.net/wiki/Auletta_krautteri  Microscopic features. Skeletal architecture simple, composed of one to three multispicule tracts oriented parallel to and lining the atrial cavity, which is relatively smooth as a result (Fig. 1B). Single, or multispicular tracts branch from this longitudinal tract approximately at right angles and project to the outer surface. The branches also form short brushes, and where each branch penetrates the surface, the terminal brush forms a tuft to produce a hispid appearance (Fig. 1C).
Each tract varies from 150-400 μm in diameter. Ascending tracts are composed primarily of straight and curved styles, and secondarily of sinuous oxeas, curved oxeas and occasional sinuous strongyles ( Fig. 1O, P). Straight styles or styles curved near the base form the exterior tips of ascending fibres and curved, bent or sinuous oxeas and styles form cross tract links.
The multi-spicule tracts of the atrial cavity are 500-700 μm diameter and composed of bundles of 10 to 15 spicules cemented by spongin Ascending tracts composed of fewer, typically 5 or 6, spicules in a bundle cemented by spongin. Atrial tracts composed primarily of sinuous oxeas, secondarily of curved and straight styles; occasionally sinuous strongyles, sinuous styles, and curved oxeas located in axial tracts.
Ectosome surface forms a reticulation in the areas with pores where it is elevated about 2 mm above the general surface. Easily detachable aspicular membranes are present on dermal surface stretched between spicule tracts, and on atrial surface below the longitudinal spicule tracts (Fig. 1B, C). The choanosome occupies the space between the detachable membranes and is distinguished by radial orientation of the spicule tracts, and by the somewhat different proportion of spicules, which is quite variable among different specimens.
Oscula may be ringed by long, straight styles singly or in tufts. Fringe may be absent, but if present, extends 100-300 μm beyond the osculum.
Stalk is denser than the tube, not hollow except near the tube base, and packed with branching and anastomosing multi-spicule tracts, forming a dense reticulation of two to ten or more spicules to a bundle cemented by spongin. Stalk tracts 100-400 μm diameter. Primary spicules sinuous strongyles which serve to reinforce the stem. The proportion of other stalk spicules is quite variable with sinuous oxeas, bent and curved and straight styles being variably the next most abundant. Sinuous styles and curved or bent oxeas are uncommon.
Spicules. Spicule types include straight (Fig. 1F) and bent (Fig. 1H) styles of the multi-spicule tracts; long, straight styles of the oscular fringe (Fig. 1E) and proximate area; sinuous (Fig. 1K, L), curved or bent (Fig. 1M) oxeas, and sinuous strongyles (Fig. 1O, P). Occasionally sinuous oxeas occur that are rounded on one end forming sinuous styles. These latter were enumerated separately to give a qualitative idea of their abundance.
Longer styles often have a reduced diameter at the head comparable to mycalostyles. Oxeas are often anisometric. Both oxeas and styles occasionally have mucronate or rounded apices. Oxeas and strongyles may occasionally be centrotylote.
Five specimens were examined in detail (Table 1). Remarks. Evident from the Table 1 above is the relatively large variability in disposition and size of spicules from specimen to specimen.  Our specimens fit the diagnosis for Auletta by Alvarez and Hooper (2002) except that the sinuous diacts are primarily oxeas in the tube and strongyles in the stem. Several species of Auletta are reported to have sinuous oxeas but no strongyles (e.g., Auletta aurantiaca Dendy, 1889, Auletta consimilis Thiele, 1898, Auletta pedunculata Topsent, 1896, Auletta lyrata (Esper, 1794)).

Auletta andamensis
Two other sponges originally assigned to Auletta have been reassigned to other genera: Auletta elegans Vosmaer, 1882, is now accepted as Semisuberites cribrosa  (Bowerbank, 1866) that might be con-specific with Auletta krautteri. However, A. rugosa in the N. Atlantic is described as bushy with irregular branches (van Soest 2013). Lambe (1895) identified four specimens from Chika Island and Unalaska Island as belonging to Axinella rugosa. However, Cuenot (1913) argued that these were not A. rugosa and proposed a new name Phakellia lambei Topsent, 1913. Lambe (1895 described his specimens as dividing close to the base into two branches which subdivide above into two lobate expansions. Conclusions. No described species have a suite of characters matching those of our specimens. We therefore propose that the Auletta in British Columbia and Alaska be considered a new species, Auletta krautteri. We suggest that the tubular forms recorded by Stone et al. (2011) are likely Auletta krautteri.
Zoogeographic range. Gulf of Alaska and south to the southern end of the Queen Charlotte Islands, BC, also central Aleutian Islands if include Axinella rugosa of Stone et al. (2011).
Ecology. The sponge is a moderately common dredged species found on rock, gravel or mud substrates. Some individuals have been found with a small red copepod (unidentified) burrowed into the surface. Two individuals examined contained a species of the isopod Gnathia, oriented head down. Unidentified gammarid amphipods and unidentified spionid polychaetes have also been observed. Numbers of the crinoid Florometra serratissima (A.H. Clark, 1907) were observed clinging to specimens of Auletta krautteri in Hecate Strait, BC.
Microscopic features. Ostia about 0.5 mm diam. in situ penetrate a thin surface membrane between lobes (Fig. 2B); weakly developed plumoreticulate skeleton of 50-100 um diameter fibers extend from base to surface; uni or pauci spicular cross connections (Fig. 2C); halichondroid (confused) skeleton toward the base. No specialized ectosomal skeleton and no axial skeleton.
Spicules. Spicule types include straight oxeas (Fig. 2E), slightly curved styles (Fig. 2G), and strongyles. Oxea tips gradually and sharply pointed; style heads smoothly rounded, slightly narrower than main style body. Styles and oxeas mostly slightly curved or straight; a few strongly curved or sinuous. Strongyles uncommon to rare. Table 2 lists spicule dimensions.
Oxea and styles in about equal numbers, and of equivalent length. A second category of styles (styles II), while of comparable length to style 1, much thinner. Also much less abundant in two specimens and absent in eight other specimens. Strongyles of comparable width to oxeas and style I, but shorter; few in number in seven specimens and absent in three other specimens. No loose raphids or trichodragmas observed.
Remarks. The paucity of thin styles suggests that these are developmental stages. The strongyles may be anomalies or, alternatively, may be associated with one area of the sponge such as the oscula or the area of attachment to the substrate.
The choanosomal skeleton of Dragmacidon kishinensis sp. n. is only weakly plumose. In our material the linear tracts are also less dense than in the type species Dragmacidon agariciformis (Dendy, 1905). In other respects it fits the diagnosis for Dragmacidon which includes species that are thickly encrusting, the surface with tubercles, ectosome without a specialized skeleton, and skeleton not differentiated into an axial or extra-axial region. It also has both oxeas and styles of similar form and in similar numbers.
It does not fit the diagnosis for Axinyssa where the choanosomal skeleton is confused; and where the spicules may be oxeas, strongyloxeas or stylote modifications of oxeas (Erpenbeck and Van Soest 2002) Twenty-six species of Dragmacidon are presently recognized (van Soest et al. 2005, World Porifera Database, accessed February 2013. Eight species can be excluded from being conspecific based on their having trichodragmas which are lacking in D. kishinensis sp. n. All but two of the remaining species without trichodragmas have oxeas and styles which are at least 50% shorter than those in D. kishinensis sp. n. The first exception is Dragmacidon oxeon which has styles and oxeas only slightly shorter than those in D. kishinensis sp. n.; however, it differs from D. kishinensis sp. n. in having a well developed detachable membrane. The second exception is Dragmacidon egregium (Ridley, 1881) which has two classes of styles, one 650-900 μm in length but the other as well as the oxeas only up to 400-450 μm in length.
The weakly developed skeleton is similar to that in Dragmacidon grayi (Wells & Wells in Wells et al. 1960) as described by Alvarez et al. (1998).
D. kishinensis sp. n. shows some similarities to species of Axinyssa (Halichondridae) including a disorganized skeleton with, in some species, vaguely ascending vertical tracts toward the periphery. Spicules include oxeas and/or strongyloxeas, here considered to have a fusiform shaft which is pointed at one end and rounded at the other. D. kishinensis sp. n. spicules consist of oxeas and styles, the latter are isodiametric rather than being fusiform. There are 28 described species of Axinyssa (van Soest et al. consulted August 2013). They are nearly all tropical.
Conclusions. Based on the comparisons listed in Table 3, our Dragmacidon is a new species. The combination of spicule types and sizes in Dragmacidon kishinensis sp. n. do not match any other Dragmacidon species described. The reduction of a plumoreticulate skeleton and evidence of unoriented spicules suggests a possible affinity with Axinyssa spp. but the latter have only oxeas or strongyloxeas while our species has both oxeas and styles as found in some Dragmacidon spp. Finally, we would not expect to find an Axinyssa sp. in the cold temperate waters of British Columbia.
Bathymetric range. One intertidal record (0.2 m above 0 m [low tide]) in a cave; otherwise 3 m to 30 m depth. Ecology. D. kishinensis sp. n. is recorded from high wave or high current energy habitats. The tough, encrusting, non branching form would be structurally adaptive for the physical impacts of strong water movement.