Biology of the Bathylagid Fish, Leuroglossus schmidti , in the Strait of Georgia, British Columbia, Canada

• Published in: Canadian Journal of Fisheries and Aquatic Sciences
• Main Authors: Mason, J. C., Phillips, A. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1985
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Canada; Pacific; British Columbia; Hake; Theragra chalcogramma; Copepods
• Online Access: http://dx.doi.org/10.1139/f85-141; http://www.nrcresearchpress.com/doi/pdf/10.1139/f85-141

The northern smoothtongue (Leuroglossus schmidti), a deep-sea smelt, coexists with Pacific hake (Merluccius productus) and walleye pollock (Theragra chalcogramma) in the Strait of Georgia, British Columbia. Their eggs and larvae rank third in abundance, and these three pelagic stocks show marked spatial and temporal overlap in deeper waters, especially during reproduction. Development to hatching occurs in the spring at depths > 150 m. Smelt larvae metamorphose at 22 mm standard length (SL), some 90 d from hatching, and juveniles join the adults at depths > 200 m by autumn. Larger juveniles mature as 2-yr-olds > 50 mm SL. Males seldom live beyond 3 yr or exceed 60 mm SL but females may live[Formula: see text] and attain 100 mm SL. Adult sex ratio is 2:3 in favor of females. Larger females are multibatch spawners, 2 batches/yr, with a mean fecundity of 100 eggs∙g −1 ∙batch −1 . Larval diet includes eggs and early stages of crustaceans dominated by Copepoda. juveniles and adults fed mainly of polychaetes, amphipods, euphausiids, and calanoid copepods found at depths > 100 m. Except for the postlarval and early juvenile stages lasting some 3 mo, the life cycle is pursued at depths > 150 m. Their bathypelagic existence in the Strait emphasizes predator avoidance coupled with low fecundity, slow growth, and short life span.