Studies On The Artificial Propagation Technology Of Rice Field Eel, Monopterus Albus

Rice field eel (Monopterus albu) is one of the economically important fish species in China. It belongs to class pisces, order synbranchiformes, family synbranchidae, and genus monopterus in taxonomy. In recent years, the natural resource of rice field eel is declining constantly because of the excessive environmental pollution and over fishing. On the other hand, the rice field eel possesses special characteristics of sex reversal, low fecundity and spitting froth nest for hatching. So, the artificial reproduction of rice field eel is difference with other fish species. It is quilt difficult to produce seeds in large scale on controlled conditions. The successful artificial breeding is limited by such factors as asynchronization of the male and female gonad development, low fertilizing rate and hatching rate, long hatching period and asynchronous hatching out, etc.This paper studies on the artificial reproduction of Rice field eel (Monopterus albus). Firstly, efforts of different exogenous hormones on induced spawning of rice field eel is analyzed in the paper. The common hormones for fish induced spawning can also be used for rice field eel. Hormone LRH-A5 is used for stimulating the maturation of gonad. Mixture of hormone LRH-A5 and DOM or DOM singly used for induced spawning. Secondly, biochemical composition and physiological functions of froth that rice field eel spits in breeding season were reported in the paper. The results showed that the froth was a glycoprotein, and the content of sugar and protein were 0.156 mg/ml and 0.249 mg/ml respectively, the ratio of protein to sugar was 1.61. The froth protein consisted of 16 kinds of amino acids, the total contents of amino acids was 201.88 mg/100ml. The physiological functions of the froth included improvement of the fertilizing rate, hatching rate and survival rate of fry, and prevent from infecting the water mold. At last, the artificial reproduction test of rice field eel under the imitated natural breeding conditions were studied. The results indicated that, under the artificially controlled conditions, the fertilizing rate and hatching rate were 6%-22% and 6%-12% respectively. But under the imitated ecological conditions, the fertilizing rate and hatching rate reached 85% and 82%-93%, respectively.Therefore semi-artificial reproduction of rice field eel under imitated ecological conditions is an effective way to produce seeds in large-scale. It provides scientific basis for artificial propagation and seed production of rice field eel.