Trachyscorpia (Mesoscorpia) eschmeyeri

Hiroyuki Motomura, Peter R. Last & Gordon K. Yearsley, 2007, Two new species of the scorpionfish genus Trachyscorpia (Sebastidae: Sebastolobinae) from the southern Indo-West Pacific, with comments on the distribution of T. eschmeyeri., Zootaxa 1466, pp. 19-34 : 33

Geographic distribution of T. (M.) eschmeyeri .

In his review of the Atlantic scorpionfishes, Eschmeyer (1969) reported that T. (M.) eschmeyeri (as T. (M.) capensis ) was distributed only off the southwestern tip of South Africa, based on previous literature reports related to Scorpaena capensis Gilchrist & von Bonde (= T. eschmeyeri ) and a single museum specimen (BMNH 1935.5.2.10, 320 mm SL). Subsequently, Parin et al. (1995) and Pakhorukov (2001) reported T. capensis (probably T. eschmeyeri ) from the Rio Grande Rise, southwestern Atlantic, on the basis of collected specimens and underwater visual observations respectively. In the Pacific Ocean, Paulin (1982) reported T. eschmeyeri (as T. capensis ) from 29 specimens (185-400 mm SL) from northern New Zealand. Eschmeyer (1986) suggested that the same or a similar species to T. capensis occurs off southern Australia, and Poss (1994) reported T. eschmeyeri (as T. capensis ) from deep continental slope waters of southern Australia (off Tasmania, Victoria and South Australia). In the Indian Ocean, Shcherbachev(1987) reported T. capensis from the West Australian Ridge and Madagascar Ridge, and Duhamel (1999) reported T. capensis from off the St Paul and Amsterdam Islands. Shcherbachev’s (1987) and Duhamel’s (1999) T. capensis possibly contain T. eschmeyeri and T. longipedicula . Specimens of T. eschmeyeri (CSIRO H 5799-01, H 3174-15, H 3174-16, and H 3174-17; see Materials and Methods) and T. longipedicula (all type specimens) examined in this study were collected from the South-West Indian and West Australian Ridges, and South-West Indian Ridge respectively; these are almost the same localities from which Shcherbachev’s (1987) specimens were collected. Williams et al. (1996) reported T. capensis and T. cf cristulata from Western Australia on the basis of CSIRO H 2625-02 and H 2616-01 respectively. Our examinations of both specimens showed that their T. capensis and T. cf cristulata were T. carnomagula and T. eschmeyeri . Judging from the previous reports and our specimens, we consider T. eschmeyeri to be widely distributed in the Southern Hemisphere, from the western Atlantic to the southwestern Pacific Ocean through the Indian Ocean, between ca. 30° and 45°S at depths of 400-1250 m.

Trachyscorpia carnomagula and T. longipedicula are allopatrically distributed in Australasia and the southwestern Indian Ocean respectively, but both species co-occur with T. eschmeyeri . Incidentally, T. cristulata (including subspecies) is distributed only in the Northern Hemisphere in the Atlantic Ocean.

Taxonomic problems of T. (T.) cristulata and T. (M.) eschmeyeri . Ginsburg (1953) recognized T. cristulata (western Atlantic Ocean) and T. echinata (eastern Atlantic) as valid species, but his data for T. echinata were based on a single specimen. Eschmeyer (1969) reviewed previous reports of cristulata and echinata , and recognized them as subspecies, T. (T.) cristulata cristulata and T. (T.) cristulata echinata , but no specimens of the latter taxon were available to Eschmeyer (1969). Since Eschmeyer (1969), all authors have followed this classification without comparing specimens of each taxon. A direct comparison of specimens from the western and eastern sectors of the Atlantic Ocean (including a range of sizes) is required to resolve the status of the species and subspecies.

Eschmeyer (1969) described T. eschmeyeri (as capensis ) on the basis of one specimen from the southeastern Atlantic (see account under ‘Geographic distribution of T. (M.) eschmeyeri ’). Characters for specimens of T. eschmeyeri examined here from the southern Indian Ocean and southwestern Pacific Ocean agree with Eschmeyer’s (1969) description of a southeastern Atlantic specimen. However, although all our preserved specimens were whitish, lacking distinct pigments (except for a black blotch on the dorsal fin in males), Eschmeyer’s specimen was tinged with black all over the body (see Eschmeyer, 1969: fig. 5C). Collections from the southeastern Atlantic Ocean are scant, so further sampling is needed to enable useful comparisons with specimens from the southern Indo-West Pacific.