Development of Larvae of the Saffron Cod, Eleginus gracilis , with Comments on the Identification of Gadid Larvae in Pacific and Arctic Waters Contiguous to Canada and Alaska

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Dunn, Jean R., Vinter, Beverly M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1984
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Arctic; Gulf of Alaska; Canada; Pacific; Arctic cod; Boreogadus saida; Chukchi; Gadus ogac; polar cod; Theragra chalcogramma; Alaska
• Online Access: http://dx.doi.org/10.1139/f84-035; http://www.nrcresearchpress.com/doi/pdf/10.1139/f84-035

A developmental series (4.2–28.7 mm standard length, SL) of larvae and pelagic juveniles of the saffron cod, Eleginus gracilis, from the Bering and Chukchi seas is described and illustrated for the first time. Larvae of E. gracilis hatch at about 3.5 mm SL, and yolk is absorbed by about 6.5 mm SL. Notochord flexion commences at about 11 mm SL and is completed by about 17 mm; transformation to the pelagic juvenile stage occurs at about 24–27 mm SL. Eleginus gracilis larvae are characterized by gut pigment and by the presence of two distinctive postanal bars of pigment. They may be distinguished from other cooccurring gadid iarvae in the Gulf of Alaska (walleye pollock, Theragra chalcogramma; Pacific cod, Gadus macrocephalus; Pacific tomcod, Microgadus proximus) as well as those in the Bering and Chukchi seas south of 70°N (T. chalcogramma, G. macrocephalus, and Arctic cod, Boreogadus saida) based on pigment patterns and meristic characters. Comments are included on the status of knowledge of larvae of three other gadids (in addition to E. gracilis and B. saida) present in North American arctic waters: ogac (Gadus ogac), toothed cod (Arctogadus borisovi) and polar cod (A. glacialis).