A description of the early life history stages of the kob, <i>Argyrosomus hololepidotus</i> (Pisces: Sciaenidae), from southern Africa

Abstract

The larval development of the kob, Argyrosomus hoblepidotus is described and illustrated from a series of specimens collected in Algoa Bay, South Africa. Larvae are moderately deep bodied (BD = 30% BL) with a convex dorsal profile and trunk tapering to a narrow caudal peduncle. The head is large, increasing from 22% BL in preflexion larvae to 35% BL in juveniles. Pre-anal length increases from 37% BL in preflexion larvae to >60% in juveniles. Notochord flexion occurs at 5–6 mm BL. Argyrosomus hololepidotus larvae are characterized by melanophores behind the head, at the anal fin base, on the caudal fin, on the abdomen, in the angle of the jaw and at the jaw isthmus. Medio-lateral pigmentation increases markedly in early juveniles. Osteological development is described from a series of cleared and stained specimens. By 14 mm BL all fins have the adult complement of spines and rays. The larvae of A. hololepidotus are briefly compared with those of other Atlantic and Indo-Pacific sciaenids.