Haploblepharus Garman

Brett A. Human, 2007, A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)., Zootaxa 1451, pp. 1-40 : 2

[[ Genus Haploblepharus Garman ]]

Introduction

Many species of scyliorhinid sharks in South Africa are common to abundant, such as those from the genera Halaelurus , Haploblepharus , Holohalaelurus (in part), Poroderma , and Scyliorhinus . Southern Africa has an unusually high percentage of scyliorhinid endemics with a total of two endemic genera and thirteen endemic species (Compagno et al, 1989; Compagno & Human, 2003; Human, 2003, 2006a, 2006b; Human & Compagno, 2006). Another unique feature of southern African scyliorhinids is their inshore habit. Typically, most scyliorhinids are found on the continental shelf or continental slope in waters greater than one hundred meters in depth (Springer, 1979). In particular, species from the genera Haploblepharus and Poroderma are commonly seen close to shore in kelp forests and/or on rocky reefs by anglers and divers in South Africa (pers. obs.).

Only limited catch data are available for Haploblepharus sharks because, when and if recorded, all species are lumped into the category “shyshark” or “unspecified shark” (Guastella, 1993; Pradervand, 1999). The low catches of “shyshark” reported by Guastella (1993) and Pradervand (1999) are due to a lack of reporting rather than low catch rates (pers. obs.). The greatest source of fishing pressure for Haploblepharus sharks probably comes from line fishing, both commercial and recreational, where persecution of these sharks exists (pers. obs.), with other sources of fishing pressure including commercial demersal trawls and, for H. edwardsii , H. pictus and to a lesser extent H. fuscus , the aquarium trade (pers. obs.). Another source of fishing pressure, on the west coast at least, are crayfish traps which apparently catch more Haploblepharus than demersal trawls, (D. Ebert, pers. comm.). Due to the heavy fishing of scyliorhinid species in southern African waters, either directed or as bycatch, and the apparent rarity of some forms, it is necessary to understand the scyliorhinid biodiversity of the region to properly manage and conserve these sharks. The morphological conservation within the group and varying colour patterns, particularly in H. pictus , has made species identification problematic within the genus.

Species identification of this group has been historically problematic and stems from the use of colour patterns, that have proven to be variable, and poor choice of morphological characters in species identification keys. Juvenile specimens that are difficult to identify with confidence further complicate species identification, and it is possible that hybridisation may be occurring between species of this genus. Many of the registered specimens that were examined in the current study proved to be misidentified, and this study aims to provide a baseline for species identification, and highlight issues of species identification in this genus that require further research. It is hoped that increasing identification accuracy will encourage more accurate catch data reporting and research on these sharks, as there are still many unanswered questions, particularly for Haploblepharus of the Eastern Cape and kwaZulu-Natal.