Pseudogramma

John E. Randall, Carole C. Baldwin & Jeffrey T. Williams, 2002, Pseudogramma xanthum, a new replacement name for a serranid fish from the subtropical South Pacific Ocean with description of the species., Zootaxa 40, pp. 1-8 : 1-3

[[ Pseudogramma australis ]]

Randall & Baldwin (1997) revised the fishes of the subtribe Pseudogrammina (Serranidae: Epinephelinae: Grammistini) and described five new Indo-Pacific species in the genus Pseudogramma . The description of one of these, P. australis , was based on specimens from Easter Island (first recorded as Pseudogramma sp. by Randall & Cea Egaña, 1984), Pitcairn Island, Gambier Group of the Tuamotu Archipelago, Rarotonga in the Cook Islands, and Ofolanga Island of the Ha’apai Group in Tonga.

Randall & Baldwin noted that the Easter Island specimens were red in life while the only western specimens for which there was information on color, the Tuamotu and Tonga fish, were yellow. However, all had basically the same pattern of rows of whitish blotches, irregular rows of dark red dots on the head, scattered dark red dots on the body, and a paleedged dark blotch on the opercle. The Easter Island specimens have modally one more dorsal ray and pectoral ray, two more anal rays, and 10 + 17 instead of 10+16 vertebrae. Easter Island is the most southern of the localities, so Randall and Baldwin wrote that it is possible that the meristic differences may be due to the lower sea temperature at Easter. They added, however, that they believed the differences were more likely genetic and elected to treat the Easter Island population as subspecifically different from the Pitcairn to Tonga populations.

We have re-examined the specimens of Pseudogramma australis , including five more uncatalogued specimens of P. australis from the Bishop Museum collected at Easter Island since 1997, and we conclude that the western populations are deserving of specific status. Not mentioned previously is the larger size of Easter Island fish. The 14 Easter Island specimens collected from six stations vary from 35-61 mm SL, with only the 35 mm specimen less than 40 mm. The 12 specimens from seven stations from Pitcairn to Tonga measure 22.4-41.0 mm SL, with only two specimens, 39.1 and 41.0 mm, larger than 35 mm.

Table 5 of the description of Pseudogramma australis (Randall & Baldwin, 1997: 21), showing the proportional measurements of eight type specimens, includes one of 26.0 mm SL from Rarotonga and one of 33.1 mm SL from Pitcairn Island. These are the two smallest specimens measured; all the others in the table are from Easter Island. These two specimens have a larger head, longer snout, larger eye, longer upper jaw, and longer predorsal length than the Easter Island specimens. It was originally assumed that these differences were ontogenetic. Now that we have measured the remaining specimens from western localities, it is apparent that these differences are diagnostic of two different species. Herein we recognize P. australis as comprising two species, one from Easter Island and the other from the western Pacific.

A specimen from Easter Island , 52.9 mm SL ( BPBM 6623 ), was designated as the holotype of Pseudogramma australis . Instead of naming the Easter Island subspecies P. a. australis , Randall & Baldwin named it P. a. pasquensis (from the Spanish name for Easter Island, Isla de Pascua), and designated the same Easter Island specimen (BPBM 6623) as the holotype of P. a. pasquensis . Simultaneously, they designated a holotype from Temoe Atoll (BPBM 13531) for the western subspecies they named P. a. australis . These type designations in the original descriptions of P. australis , P. a. pasquensis , and P. a. australis (Randall & Baldwin, 1997:23) have created nomenclatural conflicts that we resolve herein using the International Code of Zoological Nomenclature (1999; abbreviated hereafter as ICZN).

Two of the names, P. australis and P. a. pasquensis , are based on the same name-bearing type specimen (BPBM 6623). When synonyms are established simultaneously, Article 24.1 of the ICZN requires the name proposed at the higher rank to take precedence. In this case, australis was proposed for a species and must take precedence over pasquensis , which was proposed as a subspecies. Thus, P. a. pasquensis is considered a junior synonym of P. australis .

Two of the names, P. australis and its nominotypical taxon P. a. australis , are based on different name-bearing types (BPBM 6623 for P. australis , BPBM 13531 for P. a. australis ). Article 61.2.1 of the ICZN indicates: “If different name-bearing types are fixed simultaneously for a nominal taxon and for its nominotypical taxon, the fixation for the taxon at higher rank takes precedence.” The holotype of P. australis is therefore fixed as BPBM 6623 from Easter Island, and the name P. australis does not apply to the western Pacific species. The name P. xanthum nomen novum is provided herein as a new replacement name for P. a. australis . As required by ICZN Article 72.7, the holotype (BPBM 13531) for the replacement name, P. xanthum , is the same as that of the name it replaces. Based on our examination of all available specimens of P. xanthum , the species is redescribed.