Larvae and Pelagic Juveniles of Blackgill Rockfish, Sebastes melanostomus, Taken in Midwater Trawls off Southern California and Baja California

Abstract

Examination of 217 midwater trawl samples from the coastal basins off southern California [USA] and Baja California [Mexico] revealed a recurring group of rockfish species. The late larvae and pelagic juveniles of the blackgill rockfish, S. melanostomus, constituted 16% of the total number of rockfish specimens. The life-history stages of this species are described, with emphasis on the pelagic juvenile stage. Late stage larvae and pelagic juveniles develop a distinctive pattern of melanophore bands which, by disrupting the body outline, may help conceal the young during their midwater existence. Evidence from midwater trawl collections suggests that 30 mm pelagic juveniles migrate or are carried shoreward at a depth of .apprx. 200 m to the appropriate habitat for settling. The high relative abundance of blackgill rockfish pelagic juveniles in midwater trawl samples suggests that this species may represent a potential resource.