In order to investigate the difference in utilization of diets with different quality in Jian carp(Cyprinus carpio var.Jian)and allogynogenetic silver curcian carp(Carassius auratus gibelio),a 55 d growth trial was conducted and low quality diet(LQ diet) and high quality diet(HQ diet) were tested.LQ diet contained 33.91% dietary protein which is mainly from soybean meal while HQ diet contained 45.59% dietary protein which is mainly from fish meal.The initial average body weights were from 5.58 g to 5.82 g for two fish strains.The trial was carried out in a system consisting of 12 self circulation 320 L tanks.During the experiment,the fish were fed to satiation twice a day(at 9: 00 and 15:00),and uneaten feed was collected 1 h after feeding and dried.Feces were collected twice a day(at 11:00 and 16:45) from the fecal traps and dried at 70 ℃.The results show that feed intake was higher in Jian carp than in allogynogenetic silver curcian carp when fed LQ diet,while there was no significant difference between weight gain,feed conversion efficiency,protein efficiency rate and apparent digestibility.When fed HQ diet,Jian carp showed a lower feed intake,but higher feed conversion efficiency and protein efficiency rate than allogynogenetic silver curcian carp while there was no significant difference in the weight gain and apparent digestibility of both species.For Jian carp,feed intake and protein efficiency rate for the fish fed HQ diet and LQ diet were not significantly different,while the fish fed HQ diet showed higher weight gain,feed conversion efficiency and apparent digestibility.For allogynogenetic silver curcian carp,the fish fed HQ diet showed significantly higher feed intake,apparent digestibility,weight gain,feed conversion efficiency and lower protein efficiency rate.For Jian carp,body contents of dry matter,protein,lipid and energy for the fish fed HQ diet and LQ diet were significantly higher.For allogynogenetic silver curcian carp,body contents of dry matter and protein was significantly higher,while b
