Age, growth, and maturity of Trichiurus lepturus were estimated based on right-handed sagittal otoliths belonging to 1,031 fish collected from January to December 2007 in the East China Sea. The outer margins of the otolith were examined and showed that an opaque zone was formed once per year. Marginal increments in otoliths formed as annual rings between June and August, at the beginning of the spawning season. Fish growth was expressed by the von Bertalanffy growth equation, as follows: L t =494.0 (1-e-0.2453(t+-0.4822)) for females and L t =330.4 (1-e-0.4292(t+0.7513)) for males, where L t is the total length in mm and t is age in years. The growth rates of males and females were significantly different (P<0.05).The age composition ranged mostly between ages 2 and 4, and the oldest individuals were 4 years old in males and 6 years old in females. Finally, the age composition of largehead hairtail was compared with data from the 1970s and is discussed in the context of environmental changes.
KEY WORDS: anchovy, Enshu-nada Sea, shirasu catch, transport of eggs and larvae.In the western Enshu-nada Sea (WES) off the central Pacific coast of Japan, both egg abundance and the shirasu catch of Japanese anchovy ( Engraulis japonicus ) in the spring fishing period, increased in the 1990s. After 1995, however, opposite changes were observed, with a rapid increase of egg abundance in the WES. 1 This indicates that shirasu catch may not always be estimated from spawning biomass. It also suggests that this could be caused by different transport conditions of anchovy eggs and larvae to coastal fishing grounds of shirasu.The aims of this study were to estimate the advective flux of anchovy eggs from offshore spawning sites, focusing on the advection induced by warm water intrusion from the Kuroshio, and to look at the effect of egg flux on the spring fishery catch of anchovy shirasu in the WES after 1995.The data on oceanographic conditions (temperature and salinity) and number of anchovy eggs, which were collected with a modified Norpac net (mouth diameter 45 cm, 0.335 mm mesh size) by a vertical haul from 150 m to the surface at 1 m/s, in the WES have been monthly reported by the Aichi Prefectural Fisheries Research Institute. In the spring fishing period of shirasu, it is known that the fishing grounds are mainly located in the region shallower than 50 m depth in the WES (see the top panel of Fig.
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