Analysis On Growth Characteristics In Distant Hybridization F₁ From Grass Carp（ctenopharyngodon Idellus）（♀）×barbel Chub（squaliobarbus Curriculus）（♂）

The crossbreed F₁ of grass carp（Ctenopharyngodon idella）（♀）×Barbel chub（Squaliobarbus curriculus）（♂）and grass carp were used for this research.The contrast test of pond culture were designed about the two fishes from 1⁺age to 2⁺age.To evaluate the growth of the two fishes base on their morphology indices,serum biochemistry indices and serum hormone level.The research results were as follows:1.Comparison of the growth performance in the two fishes under pond culture conditionseparate pond culture:An 60-day feeding experiment for 1⁺age and 40-day for 2⁺age of the two fishes.The weight gain rate（WGR）,weight ratio,and specific growth rate（SGR）of 1⁺age F₁ are 402.61%,5.03 and 2.67%/d,appear as better growth performance then grass carp.The WGR,weight ratio and SGR of 2⁺age F₁ are 33.00%,1.33 and 0.70%,appear as lower growth performance then grass carp.F₁ were divided into three groups of large,medium and small refered to average weight of grass carp and F₁.The proportion of three groups are 29.60%,40.20%and 30.20%of 1⁺age;but different from the 2⁺age with 32.80%,48.58%and 18.62%.pond polyculture:An 60-day feeding experiment for grass carp and F₁ with the close weight in one pond.The WGR,weight ratio and SGR of F₁ are 87.97%,1.88,0.78%/d all lower than which of grass carp.2.The level of serum biochemistry and hormone in the two fishes under pond culture conditionThe level of serum biochemistry:The total protein（TP）,blood glucose（GLU）,triglyceride（TG）,cholesterol（CHO）,urea nitrogen（BUN）,creatinine（CREA）,glutamic-pyruvic transaminase（ALT）,glutamic-oxalacetic transaminease（SAT）were measured in the two fishes.With the result that a higher lever of serum biochemistry of F₁.What’s more,the TP,GUL and TG of F₁ are significantly higher than which of grass carp（P<0.05）,Showed that F₁ with a high protein,fat and carbohydrate metabolism.The level of serum hormone:The growth hormone（GH）,insulin-like growth factor-I（IGF-Ⅰ）,triiodothyronine（T₃）and tetraiodothyronine（T₄）were measured in the two fishes.With the result that a higher lever of serum hormone of F₁,and IGF-Ⅰof F₁ was significantly higher than that of grass carp（P<0.05）;Although other serum hormones of F₁were higher than grass carp,but had no significant differences（P>0.05）.