Rhinobatidae

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 : 90-91

Rhinobatidae (guitarfishes): group 2

Glaucostegus typus (giant shovelnose ray) complex

( fig. 69)

Fifteen specimens identified as G. typus were included in the analysis. These were collected from northern Australia and eastern and southern Borneo and thus represent the more eastern parts of the distribution of this species, which occurs as far west as India. One of these specimens was vouchered (GN4214 5 ANFC H 7085-02 ). These specimens comprised a single cluster ; the range of pairwise differences among specimens in this cluster was 0–3, with an average of 1.

Two additional specimens from Borneo clustered along with, but outside the specimens of G. typus . Although morphologically indistinguishable, these specimens exhibited an average pairwise difference from the specimens of G. typus of 20.5. In recognition of this molecular result, these two specimens, which were identical in sequence, have been given the designation G. cf. typus . Taxonomic investigation of these specimens needs to be undertaken.

Glaucostegus thouin (clubnose guitarfish) ( fig. 69)

The six specimens of this species were collected from localities in western and southern Borneo. These specimens represent the central portion of the distribution of this species, which has been reported as far west as the Red Sea and eastward to New Guinea. The analysis yielded a single tight cluster with the range of pairwise differences among these specimens being 0–1. These specimens clustered most closely with those of G. typus and G. cf. typus ; the average of the pairwise differences between these specimens and those of G. typus was 27.9, and between those of G. cf. typus was 36.3.

Rhinobatos cemiculus (blackchin guitarfish)

( fig. 69)

The two specimens of this species included here, both collected from Senegal, were identical in sequence. They clustered along with but outside G. typus with an average of the pairwise differences relative to G. typus of 106.9, relative to G. cf. typus 106, and relative to G. thouin 116.3. Our specimens represent only a relatively small portion of the distribution of this species, which is distributed throughout much of the northern and western coasts of Africa.

Rhinobatos rhinobatos (common guitarfish) ( fig. 69)

All 20 specimens included in the analysis were collected from Senegal and thus represent the central part of the distribution of this species, which is known from the Mediterranean Sea to Angola. The analysis yielded a single tight cluster and the range of pairwise differences among these specimens was 0–6, with an average of 2.

Rhinobatos annulatus (lesser guitarfish) ( fig. 69)

The five specimens of this southern African species all came from South Africa, and their sequences were identical. This species grouped most closely with R. rhinobatos , but the average of the pairwise differences among specimens of these two species was substantial at 122.2.

Rhinobatos cf. schlegelii ( fig. 69)

The analysis included four specimens from the Philippines (GN4388 5 BRU 071, GN2244 5 BRU 073, GN2253 5 MMLM 001, and GN2254 5 MMLM 012), identified by Compagno et al. (2005b) as Rhinobatos cf. schlegelii and considered to represent an undescribed species. However, the cluster also included a specimen (GN4326 5 JPAG 310) collected from the Philippines, and originally identified by Compagno et al. (2005b) as Rhinobatos sp. 1 , in recognition of the fact that it was a specimen of uncertain identity. Since these specimens form a single cluster, we have used the designation of R. cf. schlegelii for this Philippine species. The range of pairwise differences among these five specimens was 0–3, with an average of pairwise differences of 1.8.

Rhinobatos sp. 1 ( fig. 69)

Two specimens collected from Malaysian Borneo clustered along with but outside their congeners from the Philippines. These differed from one another by one base. This species is very similar morphologically and in color to R. formosensis from Taiwan and was considered to be conspecific with that species by Last et al. (2010c), but this analysis suggests that it likely represents an undescribed species. The average of the pairwise differences between these specimens and those of R. cf. schlegelii was 24.9.

Rhinobatos formosensis ( Taiwan guitarfish) ( fig. 69)

One specimen from Taiwan clustered along with, but outside the specimens from the Philippines and Malaysian Borneo. The color pattern and morphology of this specimen is consistent with R. formosensis . The average of the pairwise differences between this specimen and those of R. cf. schlegelii was 105.2, and between this specimen and those of Rhinobatos sp. 1 was 109.5.

Aptychotrema rostrata (eastern shovelnose ray)

( fig. 69)

Two specimens of this eastern Australian endemic were included in the analysis. These specimens differed from one another by four bases.

Aptychotrema vincentiana (southern shovelnose

ray) ( fig. 69)

The analysis included one specimen of this southwestern Australian endemic species, from the Australian National Fish Collection (GN4625 5 ANFC H 6348-06). It grouped along with but outside those of A. rostrata . The average of the pairwise differences between this specimen and those of A. rostrata was 51.

Zapteryx exasperata (banded guitarfish) ( fig. 69)

Two specimens of this species, both collected from the Gulf of California, were included; they differed from one another by a single base.

Trygonorrhina dumerilii (southern fiddler ray)

( fig. 69)

A single sample of this southwestern Australian endemic species was included in the analysis. The specimen is in the Australian National Fish Collection (GN4626 5 ANFC H 6346-22).