Early morphological development ofOmobranchus fasciolatoceps andO. Punctatus (Blenniidae: Omobranchini) reared in an aquarium

Larval and juvenile development of two blenniids,Omobranchus fasciolatocepts andO. punctatus, is described using eggs collected from natural waters in Tokyo Bay and incubated in an aquarium. These larvae and juveniles are compared with those of two otherOmobranchus species,O. elegans andO. loxozonus, distributed widely in Japan.Onobranchus punctatus is characterized by a unique, pointed snout in preflexion larvae, no melanophores proximally on the lower part of the pectoral fins in flexion and postflexion larvae, and pterygiophores projecting externally as blades between the dorsal and anal fin-rays in postflexion larvae and juveniles.Omobranchus fasciolatoceps has the following characteristics: a few melanophores on the fore-and mid-brain, but none on the hind-brain in preflexion larvae; no melanophores on the cleithral symphysis in flexion and postflexion larvae; no external pterygiophore blades in postflexion larvae and juveniles; and a unique dorsal skin flap on the head in juveniles. Ontogenetic developement of dorsal and anal pterygiophores is described forO. fasciolatoceps andO. punctatus. InO. punctatus, the postero-distal part of each proximal radial projects remarkably to form the external blades between the soft fin-rays, whereas the external blades between the fin spines are formed by fusion of a dermal bone developed from the antero-distal part of each proximal radial with the adjacent distal radial.