Cephalopholis aurantia (Valenciennes, 1828)

Randall, John E. & Justine, Jean-Lou, 2008, Cephalopholis Aurantia × C. Spiloparaea, A Hybrid Serranid Fish From New Caledonia, Raffles Bulletin of Zoology 56 (1), pp. 157-159 : 157-159

Cephalopholis aurantia × C. spiloparaea

( Fig. 1 ; Table 1)

MNHN 2006-0256 , 127 mm SL, 60 grammes (fresh weight), New Caledonia, outer reef slope, wreck of “Ever Prosperity”, 22 ° 27'30"S 166 ° 21'50"E, 56–62 m, hook and line, J.-L. Justine, 22 Aug.2006 .

Diagnosis. – Dorsal rays IX,15; anal rays III,8; pectoral rays 15; pectoral rays 18; lateral-line scales 48; body scales in longitudinal series 105; snout anterior to nostrils naked; maxilla naked; scales ventrally on abdomen cycloid, becoming weakly ctenoid posteriorly; body depth 3.0 in SL; head length 2.4 in SL; snout length 4.0 in HL; eye diameter 4.74 in SL; interorbital width 6.85 in HL; upper jaw length 2.0 in HL, the maxilla ending below posterior edge of orbit; ventral margin of preopercle fleshy; edge of subopercle and interopercle finely serrate; caudal-peduncle depth 3.45 in HL; fifth to eighth dorsal spines subequal, 3.4 in HL; second anal spine longest, 2.65 in HL; caudal fin rounded, 1.75 in HL; pectoral fins 1.5 in HL; pelvic fins not reaching anus, 2.05 in HL; colour in alcohol pale yellowish; body with a faint irregular dusky pattern from dark scale centres; interorbital, snout, and front of upper lip with irregular blackish markings; soft portion of dorsal fin with a broad dusky margin; soft portion of anal fin with a narrow blackish margin. Colour when fresh as in Fig. 3.

Evidence for hybridization. – As can be seen from a comparison of Figs. 1–3 , the hybrid is clearly closest in colour to C. spiloparaea . Table 1 shows its affinity to C. spiloparaea in having a smooth margin of the subopercle and interopercle, a body depth of 3.0 in SL, and short pelvic fins, 2.05 in head length. It is closest to C. aurantia in having 8 anal soft rays and the maxilla ending below the rear of the eye. It is intermediate to the two species in its body scale count of 105 and in the scalation of the abdomen.

Remarks. – In one character the hybrid is unlike either C. aurantia or C. spiloparaea . No scales could be detected on the maxilla. The scales are very small and partially embedded on the two parent species. It is not unusual for hybrids to exhibit a character not found in either parent species.

Cephalopholis aurantia and C. spiloparaea are both wideranging in the Indo-Pacific region from the east coast of Africa to the islands of French Polynesia (Randall & Heemstra, 1991). Cephalopholis spiloparaea is known even farther east to the Pitcairn Islands. Cephalopholis aurantia may well occur there too, but no fishing was carried out at these islands in its depth range (generally over 100 m, with one record from 300 m). Cephalopholis spiloparaea has been collected from 15 to 108 m, but mostly deeper than 30 m. Cephalopholis aurantia reaches larger size, to 225 mm SL, compared to 166 mm for C. spiloparaea (Randall & Heemstra, 1991) .

The hybrid specimen was collected for the purpose of examining it for parasites on the gills and in the digestive tract. Because it was believed to be C. spiloparaea , the gills and viscera were removed for the assay of parasites. The gills had no monogeneans, gnathiid isopod larvae, or adult copepods; only a few larval copepods were found. The digestive tract contained no digeneans or nematodes, but it

THE RAFFLES BULLETIN OF ZOOLOGY 2008

harboured adult pseudophyllidean cestodes, a very rare find (parasitological number MNHN JNC1926).

A tissue sample was saved in ethanol from the hybrid in the hope that a DNA comparison can be made with C. aurantia and C. spiloparaea . Both of these species are reported from New Caledonia; however, the second author has been unable to obtain any fresh specimens of either species.

Figures

Fig. 1. Cephalopholis aurantia, BPBM 32893, 190 mm SL, Maldive Islands. Photo by J.E. Randall.

Fig. 2. Cephalopholis spiloparaea, BPBM 13260, 165 mm SL, Pitcairn Islands. Photo by J.E. Randall.