Gonadal Maturation, Fecundity, and Stripspawning of Female Spotted Seatrout

Spotted seatrout (Cynoscion nebulosus) were collected from Matagorda Bay, Texas, from April 1984 through March 1986 and a gonosomatic index determined. Relative batch fecundity and ooycte maturation size were compared among females collected from April through October 1984, and randomly selected females were subjected to hormone-induced strip-spawning during June and July 1984. All females collected from April through August had yolked eggs and 4%-90% of fish collected in March, September, and October had yolked ova. No yolked ova were present in fish from November through February. Gonosomatic indices suggest greatest spawning activity occurred from April through May of each year. Median relative batch fecundity of females (N = 169) collected from April through October 1984 was 258 eggs/g body weight and was not significantly different from the median relative batch fecundity of 453 eggs/g body weight of hormone spawned fish (N = 16). Female spotted seatrout (N = 16) which were successfully spawned had mean ± SD vitellogenic ovum diameters (0.45 ± 0.12 mm) significantly larger than the mean diameter (0.37 ± 0.05 mm) of fish (N = 15) which did not ovulate.

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