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Scyliorhinus retifer
– Least Concern
Taxonomy
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Kingdom:
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ANIMALIA
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Phylum:
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CHORDATA
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Class:
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CHONDRICHTHYES
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Order:
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CARCHARHINIFORMES
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Family:
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SCYLIORHINIDAE
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Scientific Name:
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Scyliorhinus retifer
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Species Authority:
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(Garman, 1881)
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Common Name/s:
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| English | — | CHAIN CATSHARK, CHAIN DOGFISH |
| French | — | ROUSSETTE MAILLE |
| Spanish | — | ALITÁN MALLERO |
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Assessment Information
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Red List Category & Criteria:
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LC ver 3.1 (2001)
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Year Assessed:
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2006
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Assessor/s:
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Sherrill-Mix, S.A., Myers, R.A. & Burgess, G.H.
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Evaluator/s:
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Kyne, P.M., Stevens, J., Pollard, D., Dudley, S. & Cavanagh, R.D. (Shark Red List Authority)
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Justification:
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A common benthic catshark of the continental shelf and slope of parts of the Northwest and Western Central Atlantic. Its occurrence appears to be patchy and irregular, with adults preferring rough ground, which is difficult to trawl thus providing refuge areas for the species. In the north of its range the species prefers the outer continental shelf, but in the south is generally found below 450 m. The northern population of this species appears to be increasing. This catshark is caught occasionally in bottom longline grouper/snapper fisheries and deep-water trawls, and is collected for the aquarium trade. These impacts are considered minimal given the species’ widespread distribution, fecundity (oviparous with high laying rates documented in captivity) and the untrawlable habitat of adults. As such, Scyliorhinus retifer is assessed as Least Concern.
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Geographic Range
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Range Description:
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Northwest and Western Central Atlantic: Atlantic coast of the USA (Georges Bank to Florida and Texas) and the northern Gulf of Mexico to Nicaragua (including Mexico, Belize, Guatemala and Honduras), Barbados, area between Jamaica and Honduras (Gilhen et al. 2003, Compagno in prep. b, Compagno et al. 2005).
Relatively high concentrations of young near Cape Hatteras (North Carolina, USA) suggest a possible nursery area (Compagno in prep. b).
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Countries:
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Native:
Barbados; Belize; Guatemala; Honduras; Jamaica; Mexico (Campeche, Quintana Roo, Tabasco, Tamaulipas, Veracruz, Yucatán); Nicaragua; United States (Alabama, Connecticut, Delaware, District of Columbia, Florida, Georgia, Louisiana, Maryland, Massachusetts, Mississippi, New Jersey, New York, North Carolina, Rhode Island, South Carolina, Texas, Virginia)
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FAO Marine Fishing Areas:
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Native:
Atlantic-northwest; Atlantic-western central
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Population
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Population:
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The NMFS Northeast Trawl Survey covers the northern range of this species. After standardizing for depth and strata, a negative binomial generalized linear model suggests an average annual increase of five percent number per year for the last 30 years (R.A. Myers, unpublished data).
Distribution appears patchy and irregular ‘with areas where it is common being interspersed with those where it is rare or absent’ (Compagno in prep. b).
Juveniles are caught more frequently than adults suggesting age segregation where adults prefer rough habitat that is difficult to trawl (Castro et al. 1988).
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Population Trend:
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Habitat and Ecology
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Habitat and Ecology:
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Benthic on the outer continental shelf and upper slope at depths of 73 to 754 m (Compagno et al. 2005). However, there is geographic variation in its bathymetric distribution: in the north it occurs on the outer continental shelf, but in its southern range it is generally found below 450 m on the continental slope. Adults prefer rough rocky bottom habitats (Castro et al. 1988, Able and Flescher 1991, Compagno in prep. b).
This shark is sluggish and only occasionally leaves the bottom. Development is oviparous. Reproduction and development in captivity were studied by Castro et al. (1988) and data are summarised here. Eggs are deposited in pairs with an interval of a few minutes to eight days between the laying of successive eggcases. Three females were used to study the interval between laying of successive pairs of eggcases. The results were: female one, 70 pairs in 991 days at an average of one pair per 14.1 days; female two, 60 pairs in 991 days at an average of one pair per 16.7 days; female three, 40 pairs in 626 days at an average of one pair per 15.2 days. Egg laying can continue in isolation from males with sperm storage documented for periods of up to 843 days (Castro et al. 1988).
Stomach contents include polychaetes, squid, bony fish and crustaceans (Castro et al. 1988).
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (total length): Female: 35 cm TL (Mid-Atlantic Bight) (Compagno in prep. b), 52 cm TL (South Carolina & Florida) (Castro et al. 1988); Male: 38 cm TL (Mid-Atlantic Bight) (Compagno in prep. b), 50 cm TL (South Carolina & Florida) (Castro et al. 1988).
Longevity: 9+ years (captivity; unknown in wild) (Compagno in prep. b).
Maximum size (total length): 59 cm TL (Compagno in prep. b).
Size at birth: 10 to 11 cm TL (Castro et al. 1988).
Average reproductive age (years): Unknown.
Gestation time: Young hatch from laid eggcases after 7–12 months (Castro et al. 1988).
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: 44 to 52 eggs/year (in captivity) (Castro et al. 1988, Compagno in prep. b).
Annual rate of population increase: 5% (northern part of range) (R.A. Myers, unpublished data)..
Natural mortality: Unknown.
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System:
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Marine
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List of Habitats:
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| 10.1 | Marine Oceanic - Epipelagic (0-200m) |
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Threats
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Threats:
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This catshark is caught occasionally in bottom longline grouper/snapper fisheries and deep-water trawls. Juvenile S. retifer are caught as bycatch off the Mid-Atlantic Bight by trawls in waters deeper than 73 m. Adults are sometimes caught by trap and longline off South Carolina and Florida (Castro et al. 1988, Compagno, in prep. b). Individuals are collected for the aquarium trade.
Utilisation
Collected for the aquarium trade, not utilized for consumption.
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List of Threats:
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| 4.1.1.1 | Accidental mortality - Bycatch - Fisheries-related - Hooking (ongoing) |
| 4.1.1.2 | Accidental mortality - Bycatch - Fisheries-related - Netting (ongoing) |
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Conservation Actions
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Conservation Actions:
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None.
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List of Conservation Actions:
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| 3.1 | Research actions - Taxonomy (in place, needed) |
| 3.2 | Research actions - Population numbers and range (needed) |
| 3.3 | Research actions - Biology and Ecology (needed) |
| 3.5 | Research actions - Threats (needed) |
| 3.9 | Research actions - Trends/Monitoring (needed) |
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Bibliography
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Bibliography:
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Able, K.W. and Flescher, D. 1991. Distribution and habitat of chain dogfish, Scyliorhinus retifer, in the Mid-Atlantic Bight. Copeia 1991(1): 231–234. Castro, J.I., Bubucis, P.M. and Overstrom, N.A. 1988. The reproductive biology of Chain Dogfish, Scyliorhinus retifer. Copeia 1988: 740–746. Compagno, L., Dando, M. and Fowler, S.L. 2005. A field guide to the sharks of the world. Harper Collins Publishers Ltd., London. Compagno, L.J.V. In prep. b. Sharks of the World. An annotated and illustrated catalogue of the shark species known to date. Volume 3. (Carcharhiniformes). FAO Species Catalogue for Fisheries Purposes No. 1, Vol.3. FAO, Rome. Gilhen, J., Coad, B.W. and Hebda, A. 2003. The chain dogfish, Scyliorhinus retifer (Garman, 1881), new to the Canadian Atlantic ichthyofauna. Canadian Field Naturalist 117(3): 475–477. Shark Specialist Group. For more information, see the Specialist Group website. Sminkey, T.R. and Tabit, C.R. 1992. Reproductive biology of the chain dogfish, Scyliorhinus retifer from the Mid-Atlantic Bight. Copeia 1992(1): 251–253. Springer, S. 1979 A revision of the catsharks, family Scyliorhinidae. NOAA Technical Report. National Marine Fisheries Service Circular 422:1-152.
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