| This study established three inbreeding level groups with the F2Strongylocentrotusintermedius families as the parents, then investigated the effects of inbreeding on fertility rate,hatchability and larval development. The aim was to estimate the phenotypic, genetic charactersand select the reaction of important economic traits of F3S. intermedius families in growthperiod and harvest time. The effects of the feeding models on the growth rate and the yield andquality of gonad were studied about the F3S. intermedius. The interaction ofgenotype-environment was studied. The main results were showed as follows:This study established three inbreeding level groups (C, H and F) with the F2S. intermediusfamilies as the parents, then investigated the effects of inbreeding on fertility rate, hatchabilityand larval development. The results showed that the influence of inbreeding on fertility rate,hatchability and aberration rate of four arms larva were not significant (P>0.05). The bodylength of four, six and eight arms larva in H were significant longer than the other two groups(P<0.05). The body length of four arms larva in the C was significant longer than the F group(P<0.05), but there was not significant difference between C and F of six and eight arms larva(P>0.05). The body width of four arms larva in C were larger than F slightly (P>0.05) andsignificant larger than H (P<0.05). The body width of six arms larva in the F were significantwider than H and C (P<0.05), while not significantly different between the latter two groups(P>0.05). The body width of eight arms larva in H were significant larger than F and C (P<0.05),while not significantly different between the latter two groups (P>0.05). The length and width ofstomach in six arms larva was F> C> H. The difference were significant (P<0.05) except thelength of stomach between C and H and the width of stomach between F and C (P>0.05). Thelength and width of stomach in eight arms larva was C> H> F. The difference were significant(P<0.05) except the result between C and H (P>0.05). The results demonstrated that theinbreeding level of F<0.25was not harmful to the fertility rate, hatchability and larvadevelopment of the sea urchin S. intermedius except the development of stomach.23full-sib families in the growing period and13~23full-sib families at harvest wereselected from F3S. intermedius families to statistic the phenotypic traits and gonad traits.Estimated heritabilities and calculated the selected reaction of each characters on differentperiods separately, then compared and ranked each character of every family in harvest time(19months old). The results showed that the test diameter, test height, body weight respectivelyreached to47.84±5.89mm,22.67±3.31mm and43.29±13.05g on the19months old of the F3S.intermedius families. The wet weight of gonad was5.08±2.40g and the gonad index was11.48±4.33%. The most gonad colors between yellow and bright yellow, orange and brightorange. In14~18months old, the heritability of test diameter, test height and body weight were0.096±0.107~0.202±0.117,0.246±0.126~0.409±0.137and0.175±0.114~0.227±0.124,respectively. The gonad moisture was graded to low heritability (h2<0.2) on the19months old,test diameter, body weight, a*,△E1and△E2were graded to middle heritability (0.2<h2<0.4), test height, gonad wet weight, gonad index, L*and b*were graded to high heritability (h2>0.4).From14months old to18months old, the test diameter, test height and body weight were allpositive selection response on each month old compared with F2families. The characters ofcontrol families were all negative selection response(except the test diameter of18months old).On the19months old, all characters of F3S. intermedius families were increased comparedwith the F2(except the gonad moisture,△a*and L*) and control system(except the body weightand△1L*). Through the multiple comparison and family rank the result showed that the growthcharacter of2-family and12-family, the gonad production of14-family and the gonad color of4-family,5-family and11-family were optimal respectively. The present study indicated thatsex and family selection should be conducted to achieve the goal to the gonad enhancement.Effects of three feeding models(kelp:E1, kelp+mussel:E2, maize+mussel:E3) on growthrates throughout the whole growth cycle, gonad yield and gonad quality at harvest of the seaurchin F3S. intermedius were studied.The results showed that: the feeding model significantaffected (P<0.01) the test diameter and body weight of the sea urchin during its growth stage.The test diameter, body weight and SGR performed as: E2≥E1> E3in the three feeding model.The feeding model significant affected the gonad yield and gonad quality on19months old (P<0.05or P<0.01). E2was the optimal on the gonad wet weight and gonad index, followed by E1and E3; The E2and E1model were the optimal on the gonad moisture content and gonad color,the E3was the worst. Effects of the feeding model on male or female sea urchins were similar.The result suggested that, S. intermedius can grow good test diameter by feeding kelp only.Animal protein can significantly improve the growth rate and gonadal production of S.intermedius. Kelp+mussel model can be applied to improve the culture efficiency of the seaurchin. Maize had no beneficial effect on the promotion of the growth, gonad yield and quality ofthe sea urchin. Even animal protein was added, maize+mussel can hardly be a alternative feedingmodel in aquaculture of S. intermedius. |
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