|Scientific Name:||Schroederichthys tenuis Springer, 1966|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Reviewer(s):||Kyne, P.M., Cavanagh, R.D. & Fowler, S.L. (Shark Red List Authority)|
This small, benthic deepwater endemic catshark has a relatively restricted range in the Southwest Atlantic off Suriname and northern-central Brazil. Information on its life history and population data are sparse. It reaches a maximum size of at least 43 cm total length (TL) and is oviparous. It is taken as bycatch of bottom trawl fisheries and is occasionally landed. Landings seem to be increasing. Further studies, monitoring and more data regarding the life history and population biology of this species are needed. A new assessment is highly recommended in the near future when more information is available.
|Range Description:||The slender catshark seems to be an endemic species of the coast of Brazil and Suriname but there is no further information available regarding the range and population size of this species. It is apparently absent from Southern Brazil (Compagno, in prep. b). There is an uncertain record for the Southwest Atlantic (Argentina, off Patagonia) at the BMNH but this needs further confirmation and is possibly a misidentification.|
|FAO Marine Fishing Areas:|
Present - origin uncertain:
Atlantic – western central; Atlantic – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Little information is available about the life history of this species and very few specimens have been observed. This catshark is benthic and found at depths of 72 to 450 m (Uyeno et al. 1983, Compagno, in prep. b). Reaches a maximum size of at least 43 cm total length (TL) (Compagno, in prep. b). Compagno (in prep. b) reports that a male of 23 cm TL was immature and a male of 43 cm TL was mature, while a female of 37 cm TL was mature. |
This species is oviparous with up to two egg capsules (one per uterus) with long tendrils (filamentous extremities of the capsules) observed in pregnant females (Gomes and Carvalho 1995, Gadig et al. 1996).
Preliminary data on the feeding habits of this species indicate that it feeds on small teleosts and invertebrates (e.g., crustaceans, gastropods, squids) (Gadig et al. 1996). Compagno (in prep. b) reports that it also feeds on foraminifera, sponges and possibly other small sharks (denticles found in the stomach of an adult).
Little information is available regarding threats to this species. Preliminary observations indicate it is often caught in bottom trawl fisheries as bycatch and usually discarded due to its small size. It is occasionally landed when target species (mainly shrimp and some commercially valuable catfish) catches are low (Patricia Charvet-Almeida, pers. obs.). However, recently the landings are increasing and preliminary indications are that interest in this species is growing (Patricia Charvet-Almeida, pers. obs.) and may cause problems if this continues.
Some known intrinsic factors also could be considered threats for this catshark. Indeed its restricted range possibly makes it more susceptible than other species to negative environmental impacts of various types.
This species is present in the mouth of the Amazon River and distributed in an area highly influenced by the Amazon River discharge. Due to this distribution, it is possibly susceptible to water pollution originating in or carried by the Amazon River. In the future, increasing agricultural and industrial water pollution (chemical wastes) may be identified as threats to this species.
|Conservation Actions:||Research actions are required to better understand biological and ecological aspects of this species and propose appropriate conservation measures where necessary. Preliminary observations and data collection are underway, but better catch monitoring needs to be carried out. The development of management plans (e.g., establishment of landing quotas) may be required in the future. The establishment and enforcement of trawl free areas (protected areas) would also be an important conservation measure if catches continue increasing.|
|Citation:||Charvet-Almeida, P. 2004. Schroederichthys tenuis. The IUCN Red List of Threatened Species 2004: e.T44587A10909474.Downloaded on 20 September 2017.|