Histology of ovary development in striped knifejaw Oplegnathus fasciatus

This paper described the morphology,histology and annual change in ovary development in striped knifejaw Oplegnathus fasciatus by means of microscope.The development of the oocytes can be divided into six stages: the oocyte differentiation in the phase Ⅰ,the yolk nuclei with very distinction in the phaseⅡ;the appearance of unilayer vacuoles in the phage Ⅲ;the amalgamation of the yolk within the oocytes in the phase Ⅳ;the formation of the ripe eggs in the phase Ⅴand the degenerated oocytes in the phase Ⅵ.The main reproduction season extended from May to July,during which the ovary was variously found to be in stages Ⅳ and V.The ovary was found to be degenerated from August.The ovary developed again into the Ⅱphase from September.Until next March,the winter ovary was in stage Ⅱ.From the late March,the ovary developed again into the Ⅲ phase.The average gonado-somatic index of the ovary was found to range between 0.70% and 12.57%,indicating Oplegnathus fasciatus being among the multiple spawning species.