Reproductive biology characteristics and oocyte maturation in sea cucumbers (Holothuria leucospilota) using their own radial nerve extract (RNE)

Abstract

The article describes sea cucumbers as species with high economic value and an important role in cleaning the water environment. Currently, black sea cucumber (Holothuria leucospilota) is being tested for seed production in Viet Nam and understanding the biological characteristics of reproduction, reproductive stimulants, and gonad maturation process is very important. From individual black sea cucumbers collected in the waters of Cat Ba islands, Hai Phong city, in vitro experiments were carried out using the following methods: Checking the sex of sea cucumbers; Extraction of solution from sea cucumber nerves (RNE); Identify mature oocytes and experiment with stimulating oocyte maturation. Research results show that the female gonads of black sea cucumbers at stage IV (fully mature) have uniform egg cells/oocysts and reach 170 - 180 µm in diameter, with embryonic drops measuring 50 - 60 µm in diameter and the nucleus is 7 - 10 µm in diameter. After the eggs have been pushed out of the gonadal duct, 99% of the eggs have been activated to break the nuclear membrane and mature. Research has proposed a new artificial insemination method using sea cucumber nerve tissue extraction (RNE) solution. This method can replace the conventional method of stimulating reproduction in cases where the parent sea cucumbers have not yet reached gonadal maturity. This is an important scientific basis for research on reproductive hormones, in vitro experiments on sea cucumber oocyte maturation and improving the efficiency of sea cucumber seed production in Viet Nam.