Study on the reproductive biological characteristics of the polychaete Dendronereis chipolini distributed in Tra Vinh

Abstract

The study was conducted to investigate the reproductive biological characteristics of the polychaete Dendronereis chipolini collectedfromextensive shrimp ponds in Duyen Hai district, Tra Vinh province. Thestudywas implemented from January to April 2024. Alive polychaete samples werecollected to determine sex, fecundity, developmental stages of female gonads, and developmental characteristics of embryonic and larval stages. Theresultsshowed that mature males exhibit a bright milky green coloration, whilemature females display a dark moss green hue over their entire bodies. Theaverage absolute fecundity was found to be 247,199 eggs per female andtheaverage relative fecundity was 245,235 eggs per gramof individual. Femalegonads were observed to progress through 4 stages (I-IV) with correspondingegg size ranges of 40-60 µm, 60-80 µm, 80-100 µm, and 100-120µm, respectively. Embryonic development, from fertilizing to hatching, took7hours and 30 minutes at a temperature of 28-30 oC. Polychaete larvaeunderwent 3 stages of metamorphosis, transitioning fromtrochophorelarvaeto metatrochopore larvae, and then to nectochaete larvae, which resembleadult polychaetes in appearance.