Echinorhinidae, Gill, 1862

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 : 66-67

Echinorhinidae (bramble sharks)

Echinorhinus brucus (bramble shark) ( fig. 48)

Three specimens of this species, all collected from the western North Atlantic (i.e., Louisiana and North Carolina), were includ- ed in the analysis. One of these specimens came from the University of Florida Fish Collection (GN1983 5 UFFC 103000), and the other a specimen deposited in the Tulane University Museum of Natural History (GN1067 5 TU 172379). These specimens represent only a very small portion of the distribution of this species. The range in pairwise differences among these specimens was 2–5, with an average of 4.

Echinorhinus cookei (prickly shark) ( fig. 48)

In total, two specimens of this species were included in the analysis. One came from the Australian National Fish Collection (GN4998 5 ANFC H 6115-01) collected from Queensland, and the other was collected from California. These specimens thus represent only some of the more southern elements of the Pacific distribution of this species. These specimens differed by one base, clustering most closely with those of E. brucus . The average pairwise difference between specimens of these species was 59.3.

PRISTIOPHORIFORMES (sawsharks) Pristiophoridae (sawsharks)

Pliotrema warreni (sixgill sawshark) ( fig. 48)

Two specimens of this southern Africa endemic were included in the analysis. The specimens were identical in sequence.

Pristiophorus japonicus (Japanese sawshark)

( fig. 48)

The single specimen of this species was collected from Japan. It clustered most closely with the specimens of P. warreni ; the average of the pairwise differences between these two species was 130.

Pristiophorus cirratus (longnose sawshark) ( fig. 48)

The two specimens of this southern Australian endemic species were both collected from New South Wales and differed by a single base. The average of the pairwise differences between this species and P. warren i was 152.5, and between this species and P. japonicus 137.5.

HEXANCHIFORMES (cow and frilled sharks) Hexanchidae (sixgill and sevengill sharks)

Hexanchus nakamurai (bigeye sixgill shark) and

Hexanchus vitulus ( fig. 49)

The analysis included three specimens collected from Madagascar, the Philippines (GN2246 5 JPAG 053 of Compagno et al., 2005b), and New South Wales in Australia as well as one specimen from the Bahamas in the Caribbean Sea. It yielded a cluster consisting of the three specimens from the Indo-Pacific localities grouping with the specimen from the Bahamas. The range of pairwise differences among the three Indo- Pacific specimens was 5–15, with an average of 11.3; the average of the pairwise differences between the specimen from Australia and those from Madagascar and the Philippines was 14.5. However, the average of the pairwise differences between the specimen from the Bahamas and the three Indo-Pacific specimens was 80.7. Hexanchus nakamurai and H. vitulus have been considered to be synonyms (e.g., Compagno, 1984b; Taniuchi and Tachikawa, 1991) with a relatively broad distribution, occurring throughout the tropics and subtropics globally ( Last and Stevens, 2009). However, our results suggest that both may actually represent valid species. Given the type locality of H. vitulus is Bimini in the Bahamas and the type locality of H. nakamurai is Taiwan, the specimen from the Bahamas has been identified as H. vitulus , and those from Indo-Pacific localities have been given the designation H. nakamurai . Clearly, the conspecificity of the bigeye sixgill sharks should be examined in more detail.

Hexanchus griseus (bluntnose sixgill shark)

( fig. 49)

Specimens of this species included here were both collected from the eastern and central sectors of the North Atlantic. They differed from one another by two bases and clustered most closely with their two congeners. The average of pairwise differences between H. griseus and H. nakamurai was 103, and between H. griseus and H. vitulus 94.

Heptranchias perlo (sharpnose sevengill shark)

( fig. 49)

All four specimens of this monotypic genus included in the analysis came from Taiwan and thus represent only essentially a single locality of this global species. These four specimens were identical in sequence. All but one of these specimens are deposited in the University of Michigan Museum of Zoology (GN977, GN978, and GN979 5 UMMZ 231961).

Notorhynchus cepedianus (broadnose sevengill

shark) ( fig. 49)

The four specimens of this species included in the analysis were all collected from localities in the Pacific Ocean (e.g., California and Australia) and thus represent only a portion of the distribution of this essentially global species. The range in pairwise differences among these specimens was 0–6, with an average of 3.8.