Pseudocaranx sp.

Smith-Vaniz, William F. & Jelks, Howard L., 2006, Australian trevallies of the genus Pseudocaranx (Teleostei: Carangidae), with description of a new species from Western Australia, Memoirs of Museum Victoria 63 (1), pp. 97-106 : 102-103

Pseudocaranx sp. “dentex ”

Figures 3C , 4 , 5 ; Tables 1–3

? Scomber dentex Bloch and Schneider, 1801: 30 (orig. descr.; Rio de Janeiro, Brazil; holotype ZMB 14112 ).

? Usacaranx insulanorum Whitley, 1937: 223 , pl. 13, fig. 2 (orig. descr.; Elizabeth Reef; holotype lost).

Caranx nobilis . Grant, 1982: 302, color pl. 147 (brief descr., Qld).

Pseudocaranx dentex . Randall et al., 1990: 164 (misident. in part; brief descr.).

Material examined. 38 specimens, 162–860 mm FL. Qld, Australia: CAS 16472 (7, 404–432) , One Tree I.; QMB I.13732 (321), Noosa, 26˚23'S, 153˚07'E; QMB I.19416 (296), Cape Moreton. Lord Howe I.: AMS I.5761-001 (673); AMS I.7395-006 (18, 162–199); AMS I.17178- 045 (195); AMS I.17395-015 (2, 181–197); AMS I.23674-001 (860); CAS-SU 9158 (2, 170–198) ; BPBM 14833 (4, 145–210).

Remarks. Unlike P. georgianus from southern Australia and New Zealand, no evidence of hyperostosis of the supraoccipital is apparent in any of the large specimens available from One Tree I. In addition to having more gill rakers (Table 2), adults from off Queensland and Lord Howe Island do not have the blunt snouts (fig. 3B) that are characteristic of many large individuals from New Zealand (Ayling and Cox, 1982, pl. 19) and southern Australia ( Ogilby, 1893, pl. 24). As discussed under “Remarks” for P. dinjerra , sheared PCA analysis revealed consistent but subtle differences between all three Pseudocaranx groupings (fig. 5).

The fish from Queensland and Lord Howe Island listed above likely represent a fourth Australian Pseudocaranx species but final determination requires additional study, especially mitochondrial DNA analyses. James, 1980 reported limited movement of tagged Pseudocaranx off north-east New Zealand, so it is possible that fish from Queensland and Lord Howe Island are isolated from those in southern Australia and New Zealand. We are currently unable to distinguish them from P. dentex from theAtlanticOceanandSouthAfrica,orfromJapan Pseudocaranx sp. with 15 caudal vertebra. Two other antitropical Indo-Pacific carangids, Seriola lalandi Valenciennes and “ Caranx ” equula , also have similarly wide disjunct distributions, so this zoogeographic pattern is not unique. If Atlantic Pseudocaranx are indeed conspecific with those from Queensland offshore reefs and Lord Howe Island, then the oldest available name for them is P. dentex . If a different scientific name is required, one possibility is Usacaranx insulanorum Whitley. That nominal species was described ( Whitley, 1937) from Elizabeth Reef based on a single individual. Unfortunately, the holotype is not extant ( Eschmeyer, 1998) and no additional specimens are available from the type locality that would allow detailed comparisons. The original description included no vertebral count but the reported high number of gill rakers (14+25) agrees with specimens from One Tree and Lord Howe Islands.

Grantʼs, 1982 photograph (colour pl. 147) of a postmortem specimen from Noosa Heads, Queensland shows a fish with mostly yellow dorsal and anal fins and a faint yellow mid-lateral body stripe. The Pseudocaranx color photograph (Plate IV-19) in Randall et al., 1990 is misleading because it was taken at Easter Island (Randall, pers. comm.).

Figures

Figure 3. Heads of Pseudocaranx species: A, P. dinjerra, ANSP 148695, 230 mm FL, Cape Farquhar, WA; B, P. georgianus, USNM 385513, 275 mm FL, Sydney Fish Market; C, P. “dentex”, CAS 16472, 404 mm FL, One Tree I.; D, P. wrighti, WAM P.14007-18, 124 mm FL, Rottnest I.

Figure 4. Australian distributions of Pseudocaranx species based on material examined.

Figure 5. Sheared principal component analysis of 22 measurements for 3 Pseudocaranx taxa. PC2 loadings were associated with snout and upper jaw lengths, while PC3 was associated with straight lateral line and anal-fin base lengths; see Material and methods section for discussion of measurements used.