Rhynchobatidae

Elasmobranch, Its Implications For Global, Parasitology, Diversity And, Naylor, G. J. P., Sc, Caira, J. N., Ct, Jensen, K., Ks, Rosana, K. A. M., Fl, White, W. T., Csiro, Tas, Last, P. R., Csiro & Tas, 2012, A Dna Sequence-Based Approach To The Identification Of Shark And Ray Species And Its Implications For Global Elasmobranch Diversity And Parasitology, Bulletin of the American Museum of Natural History 2012 (367), pp. 1-262 : 89-90

Rhynchobatidae (wedgefishes)

Rhynchobatus species

The taxonomy of the genus Rhynchobatus is in need of full revision. Recent descriptions of two new Indo-West Pacific species ( Compagno and Last, 2008, 2010) has partly resolved some of the issues but further taxonomic work is required. We have attempted to employ the revised taxonomy in naming the specimens in the clusters resulting from the analysis conducted here. Our treatment was further informed by the morphological information presented for these Indo-West Pacific species by Last and Stevens (2009) and Last et al. (2010c).

Rhynchobatus australiae (whitespotted shovelnose

ray) ( fig. 69)

The analysis yielded a cluster comprised of 12 specimens collected from a diversity of localities throughout the island of Borneo, as well as from northern Australia, Singapore, Vietnam, and Thailand. One specimen is in the Australian National Fish Collection (GN2996 5 ANFC H 6221-01). These 12 specimens were generally morphologically consistent with R. australiae (see Last and Stevens, 2009). Most conspicuously, the majority of these specimens exhibited the single well-defined black pectoral fin spot, surrounded by four smaller white spots on either side of their body and lacked dark spots behind their eyes. The one exception was a relatively large specimen from Sarawak (GN2893) in which the pectoral fin spot configuration was not as distinct. The range in pairwise differences among these specimens was 0–7, with an average of 3.3.

Rhynchobatus cf. laevis and Rhynchobatus palpeb-

ratus (eyebrow wedgefish) ( fig. 69)

The analysis yielded a cluster comprised of five Australian specimens identified as R. cf. laevis and two specimens identified as R. palpebratus . One of the specimens of R. cf. laevis is vouchered in the Australian National

Fish Collection (GN4627 5 ANFC H 6319-

01). The range of pairwise differences among the seven specimens in this cluster was only 0– 4, with an average of 2.3. Within the cluster there was no evidence of the existence of subclusters of specimens of either species. Nonetheless, specimens identified as R. cf. laevis are morphologically consistent with that species as defined by Last and Stevens (2009). For example, not only do these specimens possess a diffuse black pectoral fin spot surrounded by scattered small white spots on each side of their body, but they also lack dark spots or markings near their eyes, whereas the specimens identified as R. palpebratus exhibit a well-defined black pectoral fin spot surrounded by four smaller white spots on each side of the body and also have dark spots behind their eyes. Thus, we have retained the different species designations of these specimens in order to call attention to the apparent discrepancy between color pattern and molecular data in this instance. The average of the pairwise differences between R. palpebratus and R. cf. laevis was 3. This cluster grouped within a larger cluster containing R. australiae . The average of pairwise differences between specimens identified as R. cf. laevis and those of R. australiae was 41.6 and between specimens identified as R. palpebratus and R. australiae was 41.

Rhynchobatus laevis (smoothnose wedgefish) ( fig. 69)

Another specimen (GN3004 5 ANFC H 6221-02) of this genus included in the analysis, collected from western Borneo, grouped along with but outside the cluster containing R. cf. laevis and R. palpebratus . The average of the pairwise differences between this specimen and those of R. australiae was 44.3, from those of R. cf. laevis 25 and from those of R. palpebratus 23.