Faculty of Fisheries, Kagoshima University, Kagoshima 890-0056, Japan
In order to examine the sex ratio, body size composition, condition factor and relative growth, a total of 1638 specimens of the grenadier Coelorinchus jordani (Gadiformes, Macrouridae) was collected from Kagoshima Bay, southern Japan, at 115-227 m in depth, using a commercial bottom trawler. Proportions of males and females were not significantly different in the shallow area (less than 200 m in depth), while in the deep area (above 200 m in depth), males had a significantly higher proportion than females. C. jordani had a sexual dimorphism in body size. The body size was significantly greater in the shallow area than the deep area for both sexes. Small individuals less than 20 mm in pre-anal length occurred only in the deep area. The condition factors of both males and females changed with seasonal oscillation. The symmetric relationship between pre-anal length and total length was represented by significantly different equations between sexes. The relationship between pre-anal length and body weight was described by a double-logarithmic linear equation without significant difference between sexes.