Research On The Reproductive Biology And Artificial Breeding Technique Of Southern Opsariichthys Bidens

As a carnivorous fish, the Opsariichthys bidens is belonging to Opsariichthys, Cypriniformes, which is widely distributed in east. In China, Opsariichthys bidens is an important commercially fish with character of rapid growth, delicious meat and strong disease resistance. Due to overexploitation and aquatic environment stress, a dramatic reduction in Opsariichthys bidens numbers. Some measures should to be taken urgently to protect this species. In this article, the biological characteristics, artificial breeding technique and embryo development of Opsariichthys bidens was studied. The results as follows:1. We found that the Opsariichthys bidens with morphological differentiation in males and females. The adult males is larger than females, and the obvious secondary sexual characteristics can be observed in the male. Fin types of Opsariichthys bidens are D.3,7?8.V.1,8;A.3,9?10;p.1,12?13;The number of gillrakers was between 10 and 12,and the scale type is 9'/'?40-47?/4-V,Opsariichthys bidens had two rows pharyngeal teeth and few had three rows.Teeth types of two rowswas 4.4-3.4 and 4.5-3.4 and Teeth type of three rows was 1.4.5?4.3.1.The relationship between body weight and length in Opsariichthys bidens could be described with the function of W=0.0166L^2.9615.The gonadal maturation coefficients varied from 1.37%?15.90% for male Opsariichthys bidens and 14.16%?19.97% for female,The fecundity for one year female Opsariichthys bidens was in the range of 1101.5?3298.The body length relative fecundity was in the range of 106.0?203.2 egg/cm.The weight relative fecundity was in the range of 12.6-168.6 eggs/g and egg diameter was 1.12? 1.38mm.The relationship between fecundity and body length could be described with a exponential equation:F=9.4040L²⁰¹⁸².2. Hormones of human chorionic gonadotropin ?HCG?, luteinizing hormone releasing hormone analogue?LRH-A₂? and Maleic acid to Domperidone ?DOM? were used at Opsariichthys bidens broodstock oxytocin challenge test. The results show that LRH-A₂ have the higher stability aphrodisiac qualities in Opsariichthy bidens asults broodstock. With the dose of LRH-A₂ at 1?g/kg-6?g/kg of body weight, along with the increase of LRH-A₂ does, the brood fish reach sexual maturity of a shorter time, and when it was at 8?g/kg-16?g/kg of body weight, the time of brood fish reach sexual maturity did not with significant changes. But when it was at 12-16?g/kg, the brood fish reach sexual maturity of a shorter time. The results showed that the better does of LRH-A₂ to oxytocin Opsariichthys bidens is 4-8?g/kg of body weight.3. The embryos were obtained by artificial induction of hormone-injecting in mature Opsariichthys bidens and the embryo development of the Opsariichthys bidens was observed. When water temperature is ?20-23.5? ?,39.45 h were needed to hatch the Opsariichthys bidens embryos and the accumulated hatching temperature was 877.87 ? � h. When water temperature is 20?27?,With the water temperature increasing, hatch time is shortened, but when it reached 28 ?, there has 1% deformity of all eggs. The result show that the accumulated hatching temperature of Opsariichthys bidens is between 859.6 and 923 ?� h.