|Scientific Name:||Holohalaelurus favus|
|Species Authority:||Human, 2006|
|Taxonomic Notes:||This species was previously referred to as a sub-population of H. regani (occurring off KwaZulu-Natal and southern Mozambique). A recent revision of the genus Holohalaelurus has shown that this species is in fact distinct from H. regani (Human 2006). Specimens of H. favus were first referred to and illustrated by Bass et al. (1975).|
|Red List Category & Criteria:||Endangered A2abcd+3bcd+4abcd ver 3.1|
|Reviewer(s):||Cavanagh, R.D., Stevens, J., Pollard, D., Dudley, S., Fowler, S.L. & Valenti, S.V. (Shark Red List Authority)|
The Honeycomb Izak (Holohalaelurus favus) has recently been described as a species distinct from the Izak Catshark (Holohalaelurus regani). The Honeycomb Izak has a restricted distribution in the western Indian Ocean, occurring from Durban, KwaZulu-Natal, South Africa, north to southern Mozambique at depths of 200–1,000 m on the upper to mid slope. Historically, the species was recorded from commercial and research bottom trawls made at depths of 200–420 m off KwaZulu-Natal (South Africa) and 240-740 m in southern Mozambique. Oceanographic Research Institute (ORI) data sheets indicate that it was not uncommon in the late 1960s and early 1970s. However, since the mid-1970s no specimens have been collected, even with recent biodiversity research cruises (2002 and 2003) and biodiversity trawl surveys in that region as part of the Coelacanth (Latimeria chalumnae) project in progress. The Honeycomb Izak was not recorded from more recent FRS Algoa surveys conducted off Mozambique, or during a Fridtjof Nansen survey cruise off Mozambique during 2007, although other deepwater demersal sharks were captured (P. Heemstra pers. comm. 2008). An intensive deep water crustacean fishery operates at depths of 100-600 m off Durban, and extends northwards into southern Mozambique waters. Holohalaelurus sharks from the KwaZulu-Natal and southern Mozambique region are still present in commercial fisheries landings, but apparently only rarely and species identification is not being recorded. Although the reason for the decline is unknown, this shark has not been observed for several decades, indicating serious decline, and it is therefore assessed as Endangered. Recently an offshore observer program has been launched in South Africa, and observers should be placed on demersal trawlers in the KwaZulu-Natal region, and trained to identify and record all catches of this species. Future survey work should also attempt to locate this shark.
|Range Description:||Western Indian Ocean: the known range of this shark, as assessed from Oceanographic Research Institute , Durban (ORI) records (Human 2006) is restricted to five degrees of latitude along the east African coast, from off Durban, KwaZulu-Natal, South Africa (north of 30°S), and from off southern Mozambique (south of 25°S) (Human 2006).|
Native:Mozambique; South Africa (KwaZulu-Natal)
|FAO Marine Fishing Areas:||
Indian Ocean – western
|Lower depth limit (metres):||1000|
|Upper depth limit (metres):||200|
|Range Map:||Click here to open the map viewer and explore range.|
H. favus probably exists as a single population. The population size is unknown, although it is presumed to have suffered a substantial decline in recent years.
This shark was historically regularly recorded from fishing trawls within its geographic range, however, it has not been recorded since the mid-1970s. It was historically recorded from commercial and research bottom trawls made at depths of 200–420 m off KwaZulu-Natal (South Africa) and 240–740 m in southern Mozambique. Examination of data sheets collected for this species by the Oceanographic Research Institute (ORI), Durban, indicates that this shark was not uncommon in the late 1960s and early 1970s. Since the 1970s no specimens have been collected, even with recent biodiversity research cruises (2002 and 2003) and biodiversity trawl surveys in that region as part of the Coelacanth (Latimeria chalumnae) project in progress (P. Heemstra pers. comm.; Human 2006). This species was not recorded from more recent FRS Algoa surveys conducted off Mozambique, or during a Fridtjof Nansen survey cruise off Mozambique during 2007, although other deepwater demersal sharks were captured (P. Heemstra pers. comm. 2008). The cause for this apparent decline is not known. Catch rates for this species were stable during the late 1960s to the early 1970s (ORI datasheets), followed by an abrupt lack of occurrence in trawls, therefore the decline does not appear to be related to fishing pressure (although this is uncertain). The ORI data sheets, used to refer to the previous abundance of this species, are species-specific and include morphometric data as well as sketches and notes on the sharks appearance. There is little doubt that these records refer to H. favus, and are indicative of the previous abundance of this species.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Very little data is available on the habitat and ecology of this shark. It is found on the upper to mid slope at depths of 200–1,000 m. Maximum size for H. favus is 51.5 cm total length (TL). Males are immature at 19.3 cm TL and mature at 51.5 cm TL. Females are adolescent at 29.1 cm TL and mature at 42.3 cm TL. It is probable that this shark develops one egg-case per uterus at a time, as do other members of this genus (Human 2006).|
An intensive crustacean trawl fishery exists off of Durban, and extends northwards into southern Mozambique. This deep water (100–600 m) crustacean fishery fishes towards the edge of the continental shelf in the area (Fennessy and Groenveld 1997).
Holohalaelurus sharks from the KwaZulu-Natal and southern Mozambique region are still present in commercial fisheries landings, but apparently only rarely (N. Kistnasamy, pers. comm.), and species identification is not being recorded. It is not known whether the reduced catch is due to fisheries pressure, habitat loss, pollution, or an as yet unidentified threat (Human 2006).
None currently in place. Recently an offshore observer program has been launched in South Africa, and observers should be placed on demersal trawlers in the KwaZulu-Natal region, and should be trained to identify and record all catches of this species (W. Sawer pers. comm. 2008). Recommend that surveys, including a habitat assessment for KwaZulu-Natal and southern Mozambique be conducted below 200 m.
Under the FAO International Plan of Action for the conservation and management of sharks (IPOA-Sharks), development of a shark management plan for all chondrichthyans is currently being considered in South Africa (finalisation and implementation of this plan should be considered a matter of priority and great urgency) (Anon 2004).
|Citation:||Human, B. 2009. Holohalaelurus favus. The IUCN Red List of Threatened Species 2009: e.T161652A5473210. http://dx.doi.org/10.2305/IUCN.UK.2009-2.RLTS.T161652A5473210.en . Downloaded on 09 October 2015.|
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