Open AccessThe biology of Benthosema glaciale and Ceratoscopelus maderensis (Myctophidae) in the Slope Sea off Nova Scotia, Canada
Author(s) -
R.G. Halliday,
K.J. Clark,
D.E. Themelis
Publication year - 2015
Publication title -
journal/e-journal of northwest atlantic fishery science/journal of northwest atlantic fishery science/journal of northwest fishery science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.615
H-Index - 40
eISSN - 1682-9786
pISSN - 0250-6408
DOI - 10.2960/j.v47.m708
Subject(s) - nova scotia , mesopelagic zone , temperate climate , oceanography , continental shelf , fishery , geography , water mass , geology , biology , ecology , pelagic zone
The myctophid species Benthosema glaciale and Ceratoscopelus maderensis were predominant in the catches of 10 mesopelagic fish surveys conducted in the Slope Sea, south and southeast of Nova Scotia. The area surveyed included both cold northeastern (Labrador Slope Water – LSW) and warm southwestern (Warm Slope Water – WSW) components of this water mass. The sub-polar-temperate species, B. glaciale, was found to be only about 15% as abundant in WSW as in LSW. Nonetheless, it occurred throughout WSW and reproduced there, maturing at a younger age than in LSW. The temperate species, C. maderensis, the predominant myctophid caught in WSW, had a life cycle of 1yr in most cases, but a small proportion lived for a second year and these occurred primarily in LSW. These larger animals matured sexually and contributed to spawning in the LSW/WSW boundary area, but their reproductive contribution elsewhere in LSW and in continental slope waters remains to be established. Both species had diverse diets, the taxonomic compositions of which overlapped substantially.