|Scientific Name:||Schroederichthys saurisqualus Soto, 2001|
|Red List Category & Criteria:||Vulnerable B1ab(iii,v) ver 3.1|
|Assessor(s):||Vooren, C.M. & Soto, J.M.R.|
|Reviewer(s):||Musick, J.A., Kyne, P.M., Cavanagh, R.D. & Fowler, S.L. (Shark Red List Authority)|
The known area of distribution of this recently described Brazilian endemic catshark is small, comprising only about 600 km of coastline. Within this area the species occurs at low density on the upper continental slope at depths of 250 to 500 m, and sporadically on the outer edge of the continental shelf. The species uses coral patches for egg-laying (a trawl survey caught egg-laying females on a patch of stony coral Dophelia pertusa at 317 m depth in 2001, but sampling of the same locality in 2002 revealed that the coral patch was no longer present and no S. saurisqualus were caught). The patches of coral appear to be naturally scarce and of small size, of the order of perhaps 100 to 1,000 m² only for individual patches. Such patches are vulnerable to destruction by trawl fishing operations, perhaps irreversibly or with a long recovery time at the low temperatures (approximately 5 to 8°C) that prevail in this habitat. Although coral patches may be more abundant in areas with rough bottom, which have not been studied by trawling and which may be the preferred habitat of the species, it is assessed as Vulnerable because of its low density, small range and presumed habitat loss. Further surveys are required to confirm this assessment.
|Range Description:||The area of distribution of this species, as presently known, is small, comprising only about 600 km of coastline. Within this area the species occurs at low density on the upper continental slope at depths of 250 to 500 m and sporadically on the outer edge of the continental shelf. The species uses patches of coral for egg-laying. The distribution of patches of corals determines the occurrence of this species.|
Native:Brazil (Paraná, Rio Grande do Sul)
|FAO Marine Fishing Areas:|
Atlantic – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Maximum size observed is 67 cm total length (TL) (females) and 61 cm TL (males). Females of 55 cm TL are sexually mature (Vooren, unpubl. data). |
The species is oviparous and uses patches of coral for egg-laying as evidenced by a catch of egg-laying females on a patch of the stony coral Dophelia pertusa in a trawl survey of its habitat in 2001 (Vooren, unpubl. data). The distribution of coral patches in the depth range of the species is unknown, but it is evident that such patches are naturally scarce and of small size, of the order of perhaps 100-1,000 m² only in the areas with smooth bottom, which has been studied by trawling. Coral patches may be more abundant on rough bottom, which has not been studied by trawling and which may be the preferred habitat of the species.
|Major Threat(s):||Patches of coral and of colonial branching sessile invertebrates in general appear to be the habitat necessary for the reproduction of this egg-laying shark. In areas where bottom fishing occurs, such habitat will suffer destruction, especially by trawling, and as a consequence the species will likely disappear from such areas. Indeed, further trawl sampling of the same locality (mentioned in the habitat and ecology section) only a year later revealed the coral patch was no longer present and no S. saurisqualus were caught.|
|Conservation Actions:||Areas on the outer shelf and the upper slope with patches of coral should be preserved as breeding habitat for this species. Bottom fishing should be excluded from such areas. Further survey work is required to determine its range extent.|
|Citation:||Vooren, C.M. & Soto, J.M.R. 2004. Schroederichthys saurisqualus. The IUCN Red List of Threatened Species 2004: e.T44586A10909330.Downloaded on 19 March 2018.|