Multiple Fetal Nutritional Patterns Before Parturition in Viviparous Fish Sebastes schlegelii (Hilgendorf, 1880)

Sebastes schlegelii is a commercially important fish with special viviparous reproductive system that cultured in near-shore seawater net cages East Asia. In the gonadal development of species, gonad males mature before those females, which after mating. Mating male/female fishes occurs October each year. Then, females undergoing oocyte maturation complete fertilization using stored sperm March following The pregnancy completed when larvae are produced ovary. It has been reported embryonic nutrient supply originates entirely from female systems. However, until now, nutritional patterns and processes provision S. parturition have not clear. goal this research was to study embryos, juveniles during pregnancy. Anatomical observations, light microscopy scanning electron were used developmental characteristics early embryos connecting structures between mother fetus. results showed following: (1) Placental-like found process , these placental-like proliferated fertilization. (2) encased by saclike structure composed blood vessels, connective tissue, surface epithelial cells. vessels near embryo existed thecal layer. Vascularized proliferation detected development. (3) Starting gastrula stage, connections surrounding cells loosened, ovarian fluid became abundant. addition, large number small holes cristae observed on embryo. We speculate may be able absorb nutrients fluid. (4) Yolk present throughout (5) Two types modes observed, lecithotrophic matrotrophic Three forms placental analogs exist : external absorptive surfaces; trophonemata, modifications epithelia for absorbing histotroph; follicular pseudoplacenta, close apposition follicle epithelia.