 abundance of 1.04 specimens per hour trawl (Guallart 1990). All sizes were represented in the captures (from juveniles to adults of both sexes) and observations made in later years did not reveal any significant change in the abundance of E. spinax in this area (J. Guallart pers. comm. 2006).
Catch rates in Scottish surveys from 1998–2004 were 81% of those in Ministry of Agriculture, Fisheries and Food (MAFF) surveys in the 1970s (T. Blasdale pers. comm. 2006). These surveys cannot be directly compared as they used different gear and vessels and fished different depth ranges, but they do appear to indicate that population levels have declined slightly from pre-fishery levels (Jones et al. 2005).
In southern Portugal Catch Per Unit Effort (CPUE) data for captures with deepwater longlines set from 450–780 m depth are 1.71/1,000 hooks (s.d.= 1.83) (R. Coelho unpubl. data). Deep water trawlers in the Algarve capture this species from 200–700 m depth and CPUEs are highest at 500 m depth with a capture rate of 15.74 specimens per hour (Coelho et al. 2005b). CPUE (kg per hour fished) from French deepwater trawl vessels in ICES Division VIa (West of Scotland) showed discard rates of this species to peak at 18.3 kg/hr at 500 m and then decline to 1.3 kg/hr at 700 m (ICES WD, Crozier 2003).
Eastern Central and Southeast Atlantic
This species was common off the coast of Northwestern Africa in the 1980s and was still very common in more recent surveys (Gulyugin et al. 2006).
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Etmopterus spinax is found on the outer continental shelves and upper slopes at depths of 70–2,000 m, mostly between 200 and 500 m (Compagno in prep.). In the Mediterranean E. spinax has been recorded from 300–2,000 m depth (F. Serena pers. obs. 2007). In the Adriatic Sea it is reported down to 1,200 m depth (Ungaro et al. 2001). In the Thyrrenian Sea, Italy, Cecchi et al. (2004) found the typical depth distribution to be 322–633 m. In the Gulf of Valencia, Spain it is commonly caught by commercial bottom trawls between 300 and 675 m, and is slightly more abundant below 550 m (Guallart 1990). In the northeast Atlantic E. spinax has been caught at depths of 400–1,000 m (Merrett et al. 1991a,b; Bridger 1978). In general, smaller (<30 cm) individuals tended to occur at depths of less than 500 m whilst mature individuals were found at mid-depths (500 to 600 m) (P. Crozier pers. comm.). In Sierra Leone E. spinax is found as shallow as 200 m but is a dominant species at depths greater than 400 m (Litvinov 1993). In Morocco E. spinax is captured at depths of 400–800 m, is a resident species at 400–500 m and is dominant at 600 m and sub-dominant at 600–900 m (Litvinov 1993).|
Estimated age at maturity is five to six years (Cecchi et al. 2004), although longevity is unknown for the species. Size at maturity has various estimates: females mature between >30–46 cm total length (TL); 33–36 cm (Compagno in prep); 38–40 cm (Capapè et al. 2001, Cecchi et al. 2004); 46 cm (n=76) in the northeast Atlantic (Crozier unpub. data); 31 cm in South Portugal (Coelho and Erzini 2005); and >30 cm in the Adriatic (Ungaro pers. comm.). Males mature between 25–38 cm: 33–36 cm TL (Compagno in prep.); 35 cm (Capapè et al. 2001); 38 cm (n=105) in the northeast Atlantic (Crozier unpub. data); 25 cm in South Portugal (Coelho and Erzini 2005); and 28–30 cm in the Adriatic (N. Ungaro pers. comm.). The maximum size recorded for E. spinax was a female of 60 cm TL but specimens are rarely larger than 45 cm (Compagno in prep.).
The velvet belly is ovoviviparous producing 6–20 pups per litter (Compagno in prep, Fischer et al. 1987), with a mean ovarian fecundity of 18 eggs (n=14) and a mean embryonic fecundity of 10 pups (n=15) (Crozier unpub. data). In the Thyrrenian Sea mature females were observed at 40 cm TL carrying six embryos of 6.5 cm TL in the uterus (Cecchi et al. 2004). Females produce a litter once a year (Bini 1967, Tortonese 1956) and pups are between 8 and 14 cm TL at birth (12 to 14 cm (Compagno in prep.); 10–11 cm (Fischer et