In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop （Argopecten irradians concentricus） was examined to evaluate the efficacy of a selection program c...In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop （Argopecten irradians concentricus） was examined to evaluate the efficacy of a selection program currently being carried out in Beibu Bay in the South China Sea. A total of 146 adult scallops were randomly selected from the same cultured population ofA. i. concentricus, and divided into two groups in shell length （anterior-posterior measurement）： large （4.91-6.02 cm, n=74） and small （3.31-4.18 cm, n=72）. At the same time, a control group was also randomly sampled （4.21-4.88 cm, n=80）. Mass-spawned F1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases. The effects of two-way （or upward-downward） selection on fertilization rate, hatching rate, survival rate, daily growth in shell length and body weight were assessed in the three size groups. Results show that significant differences （P〈0.01） were found in hatching rate, survival rate and daily growth of F~ progenies, but not in fertilization rate （P〉0.05）, among the three groups. The hatching rate, survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group （P〈0.05）, which in turn were larger than those of small-sized group （P〈0.05）. Responses to selection by shell length and body weight were 0.32±0.04 cm and 2.18±0.05 g, respectively, for the upward selection, and -0.14±0.03 cm and -2.77±0.06 g, respectively, for the downward selection. The realized heritability estimates of shell length and body weight were 0.38±0.06 cm and 0.22±0.07 g for the upward selection, and 0.24±0.06 cm and 0.37±0.09 g for the downward selection, respectively. The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.展开更多
Experiments on salinity tolerance of embryos and larvae of the southem bay scallop Argopecten irradians concentricus Say under controlled temperature of 28℃ showed that although the eggs were fertilized and cleaved a...Experiments on salinity tolerance of embryos and larvae of the southem bay scallop Argopecten irradians concentricus Say under controlled temperature of 28℃ showed that although the eggs were fertilized and cleaved at salinity 18.1 -37.4, they could further develop into normal D-shaped larvae only at salinity 23.4-36.1, while the trochophore larvae could develop into normal D-shaped larvae at salinity 22.1 -39.9. For 72 hours , the larvae could tolerate salinity of 18.4-43.9, the salinity favoring growth was 19.8-42.4; the suitable range was 21-36, and the optimum at about 28. They metamorphosed at salinity 18.9-43.5, optimally at 24-32.展开更多
基金Supported by the National Science and Technology Ministry(No.2007GB2E000183)the Agricultural Ministry of China(No.nyhyzx07-047)
文摘In the present study, the effect of one-generation divergent selection on the growth and survival of the bay scallop （Argopecten irradians concentricus） was examined to evaluate the efficacy of a selection program currently being carried out in Beibu Bay in the South China Sea. A total of 146 adult scallops were randomly selected from the same cultured population ofA. i. concentricus, and divided into two groups in shell length （anterior-posterior measurement）： large （4.91-6.02 cm, n=74） and small （3.31-4.18 cm, n=72）. At the same time, a control group was also randomly sampled （4.21-4.88 cm, n=80）. Mass-spawned F1 progenies from the three size groups were obtained and reared under identical conditions at all growth phases. The effects of two-way （or upward-downward） selection on fertilization rate, hatching rate, survival rate, daily growth in shell length and body weight were assessed in the three size groups. Results show that significant differences （P〈0.01） were found in hatching rate, survival rate and daily growth of F~ progenies, but not in fertilization rate （P〉0.05）, among the three groups. The hatching rate, survival rate and daily growth of the progeny of large-sized parents were greater than those of the control group （P〈0.05）, which in turn were larger than those of small-sized group （P〈0.05）. Responses to selection by shell length and body weight were 0.32±0.04 cm and 2.18±0.05 g, respectively, for the upward selection, and -0.14±0.03 cm and -2.77±0.06 g, respectively, for the downward selection. The realized heritability estimates of shell length and body weight were 0.38±0.06 cm and 0.22±0.07 g for the upward selection, and 0.24±0.06 cm and 0.37±0.09 g for the downward selection, respectively. The change in growth by bidirectional selection suggests that high genetic variation may be present in the cultured bay scallop population in China.
文摘Experiments on salinity tolerance of embryos and larvae of the southem bay scallop Argopecten irradians concentricus Say under controlled temperature of 28℃ showed that although the eggs were fertilized and cleaved at salinity 18.1 -37.4, they could further develop into normal D-shaped larvae only at salinity 23.4-36.1, while the trochophore larvae could develop into normal D-shaped larvae at salinity 22.1 -39.9. For 72 hours , the larvae could tolerate salinity of 18.4-43.9, the salinity favoring growth was 19.8-42.4; the suitable range was 21-36, and the optimum at about 28. They metamorphosed at salinity 18.9-43.5, optimally at 24-32.
