Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, 2Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, 3Nemuro Fisheries Extension Office, Nemuro, Hokkaido 087-8588, 4Nemuro Fisheries Extension Office Shibetsu Branch, Shibetsu, Hokkaido 086-1634, 5Stock Enhancement Technology Section (Akkeshi Station), Hokkaido National Fisheries Research Institute, Fisheries Research Agency, Akkeshi, Hokkaido 088-1108, 6Kushiro Fisheries Research Institute, Local Independent Administrative Agency, Hokkaido Research Organization, Kushiro, Hokkaido 085-0024, Japan
The age and growth pattern of barfin flounder Verasper moseri collected with gill nets, bottom set nets, and beam trawl nets in the eastern coastal waters of Cape Erimo, Hokkaido, Japan from April to December in 2007-2009 were examined. Numbers of individuals with an opaque edge on the blind side otolith increased in April-July but decreased in August-December. Age was determined by counting the outer margins of the transparent rings. Both males and females showed high growth rates in summer, but stagnated from November to May. Total lengths (in mm) and the ages of the fish (in years) in the catch were fitted to von Bertalanffy growth equations assuming a hatch date of April 1. Estimated equations were as follows: TLt=854.3{1−exp[−0.249(t−0.021)]} for females and TLt=518.5{1−exp[−0.512(t−0.089)]} for males. Compared to data in the literature for V. moseri from western waters, barfin flounder from the eastern waters of Cape Erimo exhibited faster growth. The summer water temperatures in the eastern waters (≤20℃) may be more suitable for rapid growth of this species.