Development of the chondrocranium of the shallow-water Cape hake Merluccius capensis (Cast.). Part 2: Viscerocranium

Abstract

The development of the viscerocranium of Merluccius capensis, from the earliest identifiable stage, is described. The anterior mesenchyme gives rise to the commissura palatoquadrati, the processus pterygoideus and the lamina orbitonasalis. The lamina orbitonasalis probably represents a suprapharyngopre-mandibula and the processus pterygoideus an infrapharyngopremandibula. A processus basalis is absent and the processus oticus represents a processus oticus internus. The hyomandibula consists of epihyal and laterohyal portions. A single suprapharyngobranchial develops, fused on to the fourth epibranchial.