Abstract: The growth performance including body weight specific growth rate(SGRs)and survival rate were measured in 10-14 months old sea urchin Strongylocentrotusintermedius in 34 full-sib families naturally challenged by syndrome disease, spine detaching disease and black mouth disease at water temperature of normal and low, respectively, to select disease-resistant and fast-growth families in sea urchin during juvenile(7-9 month old)rearing and subadult(14-17 month old)period via comprehensive disease resistance index(CDRI)calculated by weighted summation.The results showed that survival rates were ranged from 30.9% to 95.5% in the sea urchin challenged by syndrome disease, from 10.0% to 100.0% in the sea urchin challenged by spine detaching disease and from 5.6% to 84.2% in the animals infected with black mouth disease, with very significant difference in various families(P<0.01).There were higher resistances against syndrome disease in selectively bred family F7211-1, against spine detaching disease in family F7214-1 and against black mouth disease in family F7214-1, with higher CDRIs ranging from 0.29 to 0.78 in the selectively bred families, with the maximum in family F7209-1.The selection of comprehensive disease-resistant families showed more stable positive selection differential on both SGRs in juvenile stage and in adult stage culture in different seawater temperature compared with selection of specific disease-resistant families.Adults in families F7211-1, F7203-2, F7209-1 and F7214-1 showed combined abilities of disease-resistant and fast-growing at both normal and low temperature, and breedstocks were selected from these families to produce disease-resistant and fast-growth stock generations.The findings indicated that family selection can be used to improve disease resistance of sea urchin, and to achieve combined selection on disease resistance and growth rate based on CDRI.
2020, Vol. 35 
