Pelomedusa nigra Gray, 1863

Fritz, Uwe, Petzold, Alice, Kehlmaier, Christian, Kindler, Carolin, Campbell, Patrick, Hofmeyr, Margaretha D. & Branch, William R., 2014, Disentangling the Pelomedusa complex using type specimens and historical DNA (Testudines: Pelomedusidae), Zootaxa 3795 (5), pp. 501-522 : 513-514

Pelomedusa nigra Gray, 1863

Based on three syntypes from Natal, Gray (1863) described the new species Pelomedusa nigra . Boulenger (1889) lists these specimens as k, l and m in his “ Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles of the British Museum (Natural History) ”. Today, these mounted dry specimens are catalogued under the numbers BMNH 1849.1.30.27 and BMNH 1862.12.4.4–5 (the latter re-registered as BMNH 1947.3.5.80–81). Pelomedusa nigra was soon synonymized with Pelomedusa galeata ( Strauch 1865: p. 111; Boulenger 1880: p. 151, 1889: p. 198) or Pelomedusa subrufa ( Mertens 1937: p. 139; Loveridge 1941: p. 474), until Bour (1986: p. 37) resurrected it in a footnote as a subspecies of Pelomedusa subrufa . However, following Gasperetti et al. (1993) most authors abandoned the usage of any subspecies of Pelomedusa subrufa (cf. Boycott & Bourquin 2008).

The three syntypes of Pelomedusa nigra were examined for the present study and tissue for genetic investigation was extracted. We designate hereby the oldest specimen, BMNH 1849.1 .30.27 (adult male, straight carapacial length 16.19 cm; Fig. 6 , top), as lectotype of this taxon .

A fragment of the 12S rRNA gene could be sequenced from all three type specimens. In phylogenetic analyses ( Fig. 1 ), these sequences cluster with high support within lineage IX from South Africa. Moreover, the three type sequences are identical with a 12S sequence of a fresh sample from the same geographical source region (MTD T 5509, Ndumo, KwaZulu-Natal). Since we identify Testudo galeata Schoepff, 1792 with lineage IX, Pelomedusa nigra Gray, 1863 would become a subjective junior synonym of that name, if lineage IX should be considered taxonomically distinct.

Figures

FIGURE 1. Maximum Likelihood tree for Pelomedusa, based on 1848 bp of mitochondrial DNA (12S, cyt b, ND4+tRNAs), rooted with Pelusios sinuatus. The tree topology completely matches the one inferred by Bayesian analyses. Numbers along nodes indicate bootstrap support and Bayesian posterior probabilities greater than 50 or 0.95, respectively (not shown for some terminal clades with short branches). Sample codes are voucher numbers; see Table S1 for explanation. Name-bearing types (red) and paralectotypes or topotypic samples (blue) highlighted. On the right, mitochondrial lineages of Vargas-Ramírez et al. (2010) indicated. No topotypic material of Pelomedusa galeata orangensis Hewitt, 1935 could be sequenced. However, the lost holotype is thought to come from the vicinity of Kimberley (South Africa) and all South African samples belong to lineage IX, so it can be concluded that Pelomedusa galeata orangensis represents the same lineage. Inset: Helmeted terrapin from the Addo Elephant National Park, South Africa. Photo: M. Gregorič.

FIGURE 6. Dorsal and ventral views of the lectotype of Pelomedusa nigra Gray, 1863 (BMNH 1849.1.30.27, adult male, straight carapacial length 16.19 cm; top) and of the neotype of Pelomedusa gasconi Rochebrune, 1884 (ZFMK 17076, subadult female, straight carapacial length 11.18 cm; bottom). Scale bars, 3 cm. Photos: P. Campbell, A. Petzold.