Development and ecology of ocean perch larvae, Helicolenus percoides (Richardson, 1842) (Pisces:Scorpaenidae), from southern Australian waters, with notes on the larvae of other sympatric scorpaenid genera

Abstract

Helicolenus percoides development is described and illustrated from a series of larvae (n = 55; body length (BL), 1.9–12.3 mm) collected from waters around Tasmania, Australia. Broad-scale spawning occurred throughout the study area from late winter to late summer. Helicolenus larvae are characterized by a spongy tissue mass at the dorsal midline of the trunk. Larvae have 23–25 myomeres, a large finfold, three distinct areas of pigment (head, gut, and ventrally on the tail), a deep body, and a coiled, compact gut. Parietal, pterotic, preopercular, opercular, supraocular, post-temporal and supracleithral spines form by late notochord flexion. Fin development commences in the following sequence: pectoral, caudal, dorsal/anal simultaneously, and pelvic, with all fin elements present by 9.0 mm BL. H. percoides larvae are distinguished from the larvae of three other Tasmanian scorpaenid genera (Gymnapistes, Scorpaena and Neosebastes) by pigmentation, spination, morphometrics and meristics.This study addressed the question of variation within the larvae of H. percoides species. Except for variations in ventral body pigment, no differences were found to adequately support the separation of larvae examined into more than one species.