|Scientific Name:||Halaelurus boesemani Springer & D'Aubrey, 1972|
|Taxonomic Source(s):||Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fisheries Synopsis No. 125, Volume 4, Part 1.|
|Taxonomic Notes:||This species was confused with H. buergeri until Springer and D'Aubrey (1972) found it to be a different species (Compagno 1984). Previously considered to occur in the Philippines, Viet Nam and northwestern Australia but two new species recently described from Indonesia/Philippines and northwestern Australia have resulted in a more restricted range for this species (White et al. 2007). The Viet Nam populations need to be examined further as it is unsure which Halaelurus species they are (W. White pers. obs).|
|Red List Category & Criteria:||Vulnerable A2d ver 3.1|
|Assessor(s):||Kyne, P.M., Ebert, D.A., Akhilesh, K.V., Tesfamichael, D. & Valinassab, T.|
|Reviewer(s):||Pollom, R. & Jabado, R.|
|Facilitator/Compiler(s):||Jabado, R., Kyne, P.M.|
The Speckled Catshark (Halaelurus boesemani) is a relatively small (to 48 cm total length), data-poor catshark. It is known from a limited number of specimens collected from four locations along an ~900 km stretch of Somali coastline. It occurs on continental and insular shelves at depths of 29-91 m. Its entire distribution has been subject to at least four decades of unregulated commercial benthic trawling; shelf-occurring catsharks are very susceptible to capture in this fishing gear. The new Somali Fisheries Law bans benthic trawling, but it is suspected that past declines have already occurred given the long history of unregulated fishing across its entire range. Furthermore, enforcement of this new regulation will be a challenge. While specific data are lacking, a population size reduction of 30-50% is suspected over the past three generations (~45 years) based on actual levels of exploitation (bycatch) and the species is assessed as Vulnerable A2d. It is of concern that there have been no records since 1991, although it is acknowledged that research and monitoring have been limited in Somalia. Further investigation of this species is required to accurately define its range, biology, extent of catches in local fisheries and levels of declines. This assessment should be revisited as soon as this is available.
The Speckled Catshark is endemic to the Arabian Seas region where it is known only from four locations along a stretch of ~900 km of Somali coast. Although often reported from the Gulf of Aden, examination of records shows only a single specimen collected in 1933 which was specified as H. guagga by Norman (1939) from northeast Somalia, only marginally inside the Gulf of Aden (Norman 1939, Springer and D'Aubrey 1972). While records from outside of the Arabian Seas region represent different species (for example recently described species in White et al. (2007)), there is an unconfirmed report from Kenya (Compagno 1988). If confirmed, this would increase the known range, although it would still be known from ≤ 5 locations.
|FAO Marine Fishing Areas:|
Indian Ocean – western
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||To date there have been no dedicated surveys or population estimates for this species. Further research is needed to determine population size and trends in abundance. Significant declines in commercially important demersal fish species have been reported from where it occurs and areas surrounding it (Gulf of Aden and Red Sea), with many now considered overexploited (De Young 2006). Similarly, reports indicate that shark resources in the Red Sea, particularly off Sudan, Djibouti, Yemen (including the Socotra Archipelago) and Somalia were already showing signs of depletion over 15 years ago (PERSGA 2002, Glaser et al. 2015). It is therefore suspected that the Speckled Catshark has declined by at least 30-50% over the past three generation lengths (~45 years) in the Arabian Seas region.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||The Speckled Catshark occurs on continental and insular shelves at depths of 29-91 m, and reaches 48 cm total length. Nothing is known about its biology. Generation length is inferred from the similar-sized Blacktip Sawtail Catshark (Galeus sauteri) as 15 years based on ageing data from Liu et al. (2011).|
|Use and Trade:||
No utilization or commercial trade of this species is currently known to exist.
|Major Threat(s):||While no specific information is available on catches of the Speckled Catshark, the high level of exploitation across its small range is of concern. Somali waters have been subjected to intense unregulated commercial benthic trawling for at least four decades, with a long history of foreign trawl fisheries operating across the entire range of the Speckled Catshark (Glaser et al. 2015). While the new Somali Fisheries Law now bans benthic trawling, decades of unregulated trawling may have already caused population-level impacts on this species, and implementation of regulations and enforcement remain a challenge (Glaser et al. 2015). Given the small size of the species, it is unlikely to be taken in longline fisheries, but may interact with small-meshed gillnet fisheries which are used by artisanal fisheries in the region and demersal trawls from illegal fishing by foreign vessels.|
Currently there are no species-specific conservation measures in place. The new Somali Fisheries Law bans benthic trawling (Glaser et al. 2015). Research is required on life history, and its current occurrence across previous trawl grounds. Surveys are needed to further define this species' distribution and abundance to further assess status and conservation needs.
Compagno, L.J.V. 1984. FAO species catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. FAO Fisheries Synopsis No. 125, Volume 4, Part 1.
Compagno, L.J.V. 1988. Sharks of the order Carcharhiniformes. Princeton University Press, Princeton, New Jersey
De Young, C. 2006. Review of the State of World Marine Capture Fisheries Management: Indian Ocean. FAO, Rome.
Glaser, S.M., Roberts, P.M., Mazurek, R.H., Hurlburt, K.J., Kane-Hartne, L. 2015. Securing Somali Fisheries. One Earth Future Foundation, Denver, CO.
IUCN. 2017. The IUCN Red List of Threatened Species. Version 2017-2. Available at: www.iucnredlist.org. (Accessed: 14 September 2017).
Liu, K-M., Lin, C-P., Joung, S-J. and Wang, S-B. 2011. Age and growth estimates of the Blacktip Sawtail Catshark Galeus sauteri in Northeastern Waters of Taiwan . Zoological Studies 50: 284-295.
Norman, J.R. 1939. Fishes. The John Murray Expedition 1933-34. Sci. Reports, John Murray Expedition 7(1): 1-116.
PERSGA. 2002. Status of the Living Marine Resources in the Red Sea and Gulf of Aden and Their Management. Strategic Action Programme for the Red Sea and Gulf of Aden. Regional Organization for the Conservation of the Environment of the Red Sea and Gulf of Aden, Jeddah.
Springer, S. and D’Aubrey, J.D. 1972. Two new scyliorhinid sharks from the east coast of Africa, with notes on related species. Oceanographic Research Institute Investigational Report. South African Association for Marine Biological Research.
White, W.T., Last, P.R. and Stevens, J.D. 2007. Halaelurus maculosus n. sp. and H. sellus n. sp., two new species of catshark (Carcharhiniformes: Scyliorhinidae) from the Indo-West Pacific. Zootaxa 1639: 1-21.
|Citation:||Kyne, P.M., Ebert, D.A., Akhilesh, K.V., Tesfamichael, D. & Valinassab, T. 2017. Halaelurus boesemani. The IUCN Red List of Threatened Species 2017: e.T161488A109905403.Downloaded on 21 February 2018.|