Plectranthias lasti

description

Among other characters, Randall & Hoese (1995) used the number of lateral-line scales to differentiate P. lasti from P. megalophthalmus and P. fijiensis (30 in P. lasti, 31 in P. megalophthalmus and 32 P. fijiensis). However, the holotype of P. lasti has 30 tubed scales on the left side, and 32 on the right, and the non-type specimens of P. lasti extend variation in this character to 28 – 32. Moreover, the Queensland specimen of P. megalophthalmus has 32 / 33 lateral line scales. The new specimens also extend known variation in several other characters that were proposed to differentiate the three species. Not-withstanding the small sample sizes, two characters appear to differentiate P. lasti from P. megalophthalmus: number of segmented dorsal rays (14 in P. lasti versus 15 in P. megalophthalmus); and number of scales below the lateral line to the anal origin (9 – 10 versus 12 – 13). Disregarding the Queensland paratype (discussed above), P. lasti is distinguished from P. fijiensis in pectoral ray branching (only upper 1 – 4 rays unbranched in P. lasti versus first and ninth through 12 th unbranched in P. fijiensis), the absence of scales on the mandible (versus posterior part of

Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species

diagnosis

Diagnosis. The following combination of characters distinguishes P. lasti from congeners: dorsal rays X, 14; pectoral rays 15 – 16, usually 15, with all but upper 1 – 4 rays branched; preopercle edge smooth; scales below lateral line to origin of anal fin 9 – 10; and pelvic fin length 20.9 – 23.3 % SL.

Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species

discussion

Remarks. Plectranthias megalophthalmus was described by Fourmanoir & Randall (1979) from the 61 mm SL holotype collected from south of the Isle of Pines, New Caledonia. Allen (1985) and Paxton et al. (1989) later recorded the species from the North West Shelf of Australia based on three specimens in the Australian Museum. The species has since been recorded in Australian faunal lists (see synonymy above). Randall & Hoese (1995) subsequently described P. lasti on the basis of the holotype from the North West Shelf and a paratype from south of Marion Reef, off Queensland. They noted that P. lasti was close to P. megalophthalmus and P. fijiensis Raj & Seeto, 1983, sharing similar meristic values with those species, as well as unusual smooth preopercles. However, they did not mention the three North West Shelf specimens of P. megalophthalmus. We examined the three specimens, compared them with the holotype of P. lasti, and have concluded that they are conspecific. We are unaware of any additional specimens of P. megalopthalmus from the North West Shelf. However, we tentatively identify a specimen from the Marion Plateau off Queensland as this species (see account for P. megalophthalmus

Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species

materials_examined

Material examined. Western Australia, Australia. AMS I. 22807 - 056, 48.4 mm SL (holotype), North West Shelf, 175 km north of Port Hedland, 18 ° 32 ′ S, 118 ° 17 ′ E, 200 – 204 m, Engel trawl, J. R. Paxton, RV Soela, 2 Apr 1982; AMS I. 22828 - 020, 3: 59.6 – 62.6 mm SL, North West Shelf, 190 km northwest of Port Hedland, 19 ° 01 ′ S, 117 ° 12 ′ E, 200 – 202 m, Engel trawl, J. R. Paxton & M. McGrouther, RV Soela, 14 Apr 1982; NMV A 29655 - 001, 2: 32.7 – 47.1 mm SL, Western Australia, Barrow L 1 transect, 21 ° 00.82 ′ S, 114 ° 39.15 ′ E to 21 ° 00.78 ′ S, 114 ° 38.90 ′ E, 258 – 271 m, RV Southern Surveyor, 10 Jun 2007. Queensland, Australia. CSIRO H 651 - 02, 68.0 mm SL (paratype), south of Marion Reef, 19 ° 43.7 ′ S, 152 ° 06.4 ′ E to 19 ° 46.3 ′ S, 152 ° 04.5 ′ E, 368 – 370 m, trawl, P. R. Last, RV Soela, 23 Nov 1985 (field station SO 06 - 85 / 32)

Review of Australian species of Plectranthias Bleeker and Selenanthias Tanaka (Teleostei: Serranidae: Anthiadinae), with descriptions of four new species