Some Data on Reproductive Biology of Spotted Ghoul Inimicus sinensis (Synanceiidae)

Abstract

Gonadal structure, cytological condition of oocytes, ultrastructure of egg envelope, and spermatozoa morphology are studied in the individuals of Inimicus sinensis 120–230 mm TL with the gonads mainly at maturity stage IV. The males possess hypertrophied urinary bladders. Based on oocytes’ size distribution in the ovaries, the oogenesis is continuous and the spawning is multiple. Oocytes of the maturation period are 600–700 µm in diameter. The batch fecundity is 15 380 oocytes on average. The zona radiata of oocytes that have completed growth is 10.2 µm in width on average and it consists of two layers. The narrow outermost layer of the egg envelope approximately 0.34 µm width is most likely chorion. Spermatozoon ultrastructure of I. sinensis does not notably differ from that in other representatives of the suborder Scorpaenoidei with external insemination. The centriolar complex is characterized by orthogonal position of centrioles. Based on ovarian structure, the representatives of the genus Inimicus do not differ from the majority of teleost fishes and viviparous species of the genera Sebastes and Sebastiscus. However, many representatives of the suborder Scorpaenoidei have unique ovarian structure with the central ovigerous stroma attached to the anterior part of the ovary. Based on the current phylogenetic schemes, this ovarian type evolved independently in several evolutionary lineages.