DESCRIPTION OF EARLY STAGES OF WHITE SEABASS, ATRACTOSCION NOBILIS, WITH NOTES ON DISTRIBUTION

Abstract

Eggs, larvae, and juveniles of Atractoscion nobilis, reared in the laboratory, are described and compared with those of Cynoscion species. Eggs of A. nobilis are among the largest reported for a sciaenid species (1.24-1.32 mm diameter), and the larvae have a distinctive morphology and pigment pattern that contrasts sharply with that of Cynoscion species. The larvae are robust, with long pectoral and pelvic fins and have a solid pigment sheath of melanophores and xanthophores that initially covers the head and trunk and expands to cover the body completely. The only other sciaenid with similar developmental stages is Sciaena umbra of the eastern Atlantic, Mediterranean, and Black Sea. Late-stage larvae of Larimus fasciutus of the western Atlantic have large, heavily pigmented paired fins, but the body pigment is not a solid cloak as in A. nobilis. Atractoscion larvae occurred in only 104 samples of all CalCOFI collections made between 1950 and 1978. Larvae occurred from Santa Rosa Island, California, to Santa Maria Bay, Baja California, with highest concentrations in the Sebastian Viscaino Bay and San Juanico Bay regions. Most of the larvae occurred from May to August, with a peak in July. RESUMEN Se describen 10s huevos, larvas y juveniles de Atruetoscion nobilis cultivadas en el laboratorio, y se comparan con especies de Cynoscion. Entre las especies de Sciaenidae, 10s huevos con mayores dimensiones corresponden a A. nobilis (1.24-1.32 mm. de diametro), y sus larvas muestran una morfologia bien definida, con el pigmento distribuido de forma diferente a la que presentan las especies de Cynoscion. Las larvas son robustas, con aletas pectorales y pelvicas largas, y llevan pigmento que incluye melanoforos y xantoforos. Esta capa de pigmento cubre inicialmente la cabeza y tronco, extendikndose hasta cubrir completamente el cuerpo. Sciaena umbra es otro Sciaenidae con fases de desarrollo similar, y habita el Atlantico oriental, Mar Mediterraneo y Mar Negro. Las ultimas fases larvales de Larimus fasciutus del