Dark Shyshark

description

Description. Morphometric and meristic data are given in Table 2. The following is based on the mean measurements of H. pictus specimens examined by the author (see Study material): H pictus is a slender to moderately stocky bodied Haploblepharus shark with a relatively broad head, head width at the pectoral origin 3.63 times the preoral length; head length 1.26 times distance from snout tip to first gill slit; height of first gill slit 1.76 times the height of the fifth gill slit; eye length 4.29 times longer than spiracle length; basimandibular cartilage found at the symphysis of the Meckels cartilage in the lower jaw; mouth length 1.23 times the prenarial length; mouth width 6.6 times the upper labial furrow length; labial cartilages present; nasal lobes fused into a nasal flap that covers the excurrent apertures and extends to the mouth; interorbital width 1.19 times the nasal flap width; head very strongly depressed, head width at the posterior margin of the orbit 1.95 times its height; head width 1.48 times its height; trunk depressed, trunk width 1.21 times its height; abdomen not depressed, abdomen width 0.99 times its height; tail not depressed, tail width 1.04 times its h

A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

diagnosis

Diagnosis. The author was not able to personally measure the putative type series (see remarks below), and given the highly contorted condition of those specimens, the measurements obtainable from those specimens would likely be inaccurate. The following is based on the mean measurements of H. pictus specimens examined by the author (see study material). Haploblepharus pictus is distinguished from other Haploblepharus sharks in having a slender body in juvenile individuals but becoming stockier in mature individuals, abdomen width 11.2 % TL; snout broadly rounded, not coming to a point; head width at the posterior margin of the orbit 13.0 % TL; head strongly depressed, head height at the posterior margin of the orbit 6.7 % TL; trunk somewhat depressed, trunk height 10.2 % TL and trunk width 12.3 % TL; claspers of mature males stout, inner length 6.2 times the base. Haploblepharus pictus specimens have 45 – 83 rows of teeth in the upper jaw (mean 72.0) and 47 – 75 rows of teeth in the lower jaw (mean 62.8). The number of vertebral centra in H. pictus specimens ranges from 93 – 133 (mean 124.5) total. Haploblepharus pictus has a highly variable colour pattern that can superficially r

A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

discussion

Remarks. Müller & Henle (1838 – 1841) refer to specimens in the Museum in Leyden (now the Rijksmuuseum van Natuurlijke Historie, Leiden, RMNH) and in the British Museum (BMNH), but give no further details of the type material. RMNH 4161 and RMNH 4164 bear the name Scyllium edwardsii, while RMNH 4162 and RMNH 4163, have two names written on the label, Scyllium edwardsii and Scyllium pictum. All four lots were in the museum during the time of Müller and Henles’ visit to the museum (M. van Oijen, pers. comm.). Photographs of these specimens (supplied by M. van Oijen) were examined by the author. The specimens are in poor condition, and although the colour patterning on most of the specimens are considerably faded, saddles are visible on all specimens, and all specimens appear to be H. pictus. Although there is no label identifying them as such, the RMNH specimens are probably the syntypes for H. pictus. Of the scyliorhinid specimens in the BMNH that have been assigned a species name, none are referable to H. pictus. As there are many lots in the BMNH under the name Scyllium sp, it was not practical to examine all of these specimens remotely, and the status of types for H. pictus in th

A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)

distribution

Distribution. Figure 6 shows the distribution of H. pictus as verified by this study. Haploblepharus pictus occurs north of Lüderitz, Namibia, extending south into South Africa to Cape of Good Hope, then east to into the Indian Ocean, east of the Storms River mouth, Eastern Cape. The present revision of Haploblepharus has led to a major range extension for H. pictus, which was previously thought to occur only as far east as Cape Agulhas (Bass et al., 1975; Compagno, 1988; Compagno et al., 1989). The previous distribution of H. pictus was due to misidentification of this species with H. edwardsii and H. fuscus, the former in particular, east of Cape Agulhas. Haploblepharus pictus seems to be more abundant west of Cape Agulhas (which makes it somewhat surprising that it was not recorded by Clark (1997 )), although it appears not to be uncommon east of Cape Agulhas. Dr. P. D. Cowley (SAIAB) has shown the author photographs of a number of live Haploblepharus specimens from Titsikama National Park, Eastern Cape, with colour patterns that resemble H. edwardsii, however, these specimens proved to be H. pictus.

A taxonomic revision of the catshark genus Haploblepharus Garman 1913 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae)