A Comparision Of Maily Characters Between Hybrid Catfish(Silurus Meridionalis G.♀×Silurus Asotusl.♂) And Silurus Asotus

Hybrid catfish (Silurus meridionalis G.♀×Silurus asotus L.♂) and its father, Silurus asotus,wereraised for42days under the same condision,and the growth conditions,the morphological characters,themeat rate and the muscle nutrient composition were determined.The results showed that hybrid catfish notonly growed quicker than Silurus asotus, but also was moderate and weaker cannibalism than Silurusmeridionalis.The difference of morphological characters between hybrid catfish and Silurus asotus wassmall.The meat rate and the muscle nutrient composition of hybrid catfish was better than Silurus asotus’.1The comparation of the growth conditions between hybrid catfish and Silurus asotusThe survival rate of hybrid catfish and Silurus asotus were84%and97%,respectively.And the formerwas great marked higher than the latter（P＜0.01）.Hybrid catfish’s speed of growth,including body weight gain(WG）,body length increase (BLI),average daily gain（ADG)，specific growth rate （SGR）, which was151.18%,1356.12%,2.28g,6.38%,respectively,was great marked faster than Silurus asotus,which was95.76%,756.31%,1.00g,4.62%,respectively.Food conversion ratio(FCR）of the two kinds of fishes was1.44and2.05, respectively.Moreover,hybrid catfish was great marked lower than Silurus asotus（P＜0.01）.The hybrid catfish showed bettergrowth conditions.2The comparation of the morphological characters between hybrid catfish and Silurus asotusThe difference of the outside morphological characters between hybrid catfish and Silurus asotus wasnot marked（P＞0.05）. The caudal fin of hybrid catfish has not the same length, which was approached tothe mather’s.The numbers of Anal and Vertebrae of hybrid catfish were78～82,62,which were more than that ofSilurus asotus,which were74～78and58,and so hybrid catfish was longer than Silurus asotus. The hybridcatfish was great larger than Silurus asotus,and all of the scalability characters had great marked differencethan Silurus asotus（P＜0.01）.The ratio of body length and head length, head length and eye length, mouth width and body width, mouth length and head length of hybrid catfish had great marked difference （P＜0.01）with the ratio of Silurus asotus.The ratio of body length and body height,body length and intestinelength of hybrid catfish had marked difference（P＜0.05）with the ratio of Silurus asotus. The ratio of thelength from ventral fin to pectoral fin and body length between hybrid catfish and Silurus asotus had greatmarked difference（P＜0.01）. The hybrid catfish had bigger head, higher body, wider mouth, who hadsome difference from Silurus asotus.3The comparation of the meat rate and the muscle nutrient composition between hybrid catfish andSilurus asotusThe meat rate and the muscle nutrient composition of hybrid (Silurus meridionalis G.♀×Silurus asotusL.♂) and its father were measured and analyzed.The results showed that the meat rate of hybird catfish（60.02%）was higher than that of Silurus asotus（42.80%）.The crude protein content of hybird（17.58%）was higher than that of Silurus asotus（16.39%）,but the crude fat（0.44%）was lower than that in Silurusasotus（0.96%）.TAA（89.80%）,EAA（36.27%）,DAA（33.92%）in hybird were slightly higher than thatin Silurus asotus（86.13%,34.74%,32.51%）respectively,and the animo acids modle of hybird was moreclosely to the FAO/WHO mode.Lastly,the content of USFA in hybird was more than that in Silurusasotus,espetially the content of Linolenic acid（33.93%）,which was obviously higher than that in Silurusasotus（19.29%）.In summary,hybird catfish(Silurus meridionalis G.♀×Silurus asotus L.♂) whose musclewas better than its father’s,was one of the waterfish with better nutritive value.