不同饵料对中间球海胆摄食与生长及硫酸软骨素积累的影响

Effects of different diets on Strongylocentrotus intermedius feeding,growth and chondroitin sulfate accumulation

【目的】明确海带、江蓠和石莼3种饵料对中间球海胆摄食、壳径增长、体质量增长、性腺颜色及硫酸软骨素积累的影响,为筛选适宜的养殖海胆饵料及合理制定鲜饵料匮乏期的中间球海胆投喂计划提供理论依据。【方法】将中间球海胆按投喂饵料分为海带投喂组、江蓠投喂组和石莼投喂组,在投喂第30、60和90 d,利用游标卡尺测定海胆壳径和壳高,使用天平测定海胆体质量和性腺重量,计算日平均摄食率、饵料系数、壳径特定生长率、体质量特定生长率和性腺指数;通过色度计测定性腺颜色并计算色差;采用酶联免疫分析法(ELISA)测定中间球海胆性腺硫酸软骨素含量和硫酸软骨素合酶活性。【结果】随着投喂时间的推移,各处理组中间球海胆的日平均摄食率呈下降趋势,江蓠投喂组日平均摄食率最高,其次是海带投喂组,石莼投喂组中间球海胆的日平均摄食率最低;在各时间段,饵料系数最高的是江蓠投喂组,其次是海带投喂组,最低的是石莼投喂组,且三者差异显著(P<0.05,下同);随投喂时间的推移,各处理组中间球海胆的壳径特定生长率和体质量特定生长率均呈下降趋势,在相同投喂时间下,各处理组的海胆壳径特定生长率和体质量特定生长率均差异显著,排序均为海带投喂组>石莼投喂组>江蓠投喂组;3个处理组的中间球海胆性腺指数存在一定差异,排序为海带投喂组>石莼投喂组>江蓠投喂组;江蓠投喂组和海带投喂组中间球海胆性腺颜色较优,江蓠投喂组性腺红度在各投喂时间段均最高,且在第90 d江蓠投喂组性腺黄度显著高于其余处理组,海带投喂组性腺亮黄色差在各投喂时间段均最低;江蓠投喂组的中间球海胆性腺硫酸软骨素含量和硫酸软骨素合酶活性最低,海带投喂组和石莼投喂组无显著差异(P>0.05)。【结论】不同饵料对中间球海胆摄食、壳径增长、体质量增长、性腺发育和品质及硫酸软骨素积累存在不同影响,在海带匮乏期可通过投喂石莼和江蓠进行有效补充,从而保障中间球海胆的生长和发育。

【Objective】To clarify the effects of Saccharina japonica,Gracilaria verrucosa and Ulva lactuca on the feeding,shell diameter growth,body weight growth,gonadal color and chondroitin sulfate accumulation in the sea ur-chin Strongylocentrotus intermedius.Additionally,to provide a theoretical basis and new clues for the screening of sui-table diets and developing reasonable breeding strategy for cultured S.intermedius during fresh diets shortage period.【Method】The S.intermedius were divided into S.japonica feeding group,G.verrucosa feeding group and U.lactuca feeding group according to the feeding bait,and on the 30th,60th and 90th d after feeding,the vernier calipers were used to determine the shell diameter and shell height of S.intermedius,and the balance was used to determine the body weight and gonad weight,and the average daily feeding rate,diet coefficient,growth rate of shell diameter,specific growth rate,and the gonad index were calculated,and the chondroitin sulfate content of S.intermedius gonad and the activity of chon-droitin sulfate synthase were determined by enzyme-linked immunoassay(ELISA).【Result】As feeding time progressed,average daily feeding rate of S.intermedius in each experimental group showed a generally downward trend.The average daily feeding rate of S.intermedius in G.verrucosa feeding group was the highest,followed by the S.japonica feeding group,and the average daily feeding rate of S.intermedius in U.lactuca feeding group was the lowest.In each time period,the highest diet coefficient was in the G.verrucosa feeding group,followed by the S.japonica feeding group,and the lowest was in the U.lactuca feeding group,and there were significant differences among the three groups(P<0.05,the same below).The shell diameter growth rate and specific growth rate of S.intermedius showed a decreasing trend with feeding time passed,and at the same feeding time,there were significant differences in the shell diameter growth rate and specific growth rate among treatment groups,with the order being S.japonica feeding group>U.lactuca feeding group>G.verrucosa feeding group.There were some differences in the gonadal index of S.intermedius among the three treatment groups,in the order of S.japonica feeding group>U.lactuca feeding group>G.verrucosa group,and the gonadal color of S.intermedius was superior in G.verrucosa feeding and S.japonica feeding groups.The gonadal redness was the highest at all feeding times in the G.verrucosa feeding group,and gonadal yellowness was significantly higher in the G.verrucosa feeding group than in the rest of the treatment groups at the 90th d,while the difference in gonadal bright yellow coloration was the lowest in the S.japonica feeding group at all feeding time.Chondroitin sulfate content and chondroitin sulfate synthase activity in the gonads of S.intermedius were the lowest in the G.verrucosa feeding group.There were no significant differences between the S.japonica and U.lactuca feeding groups(P>0.05).【Conclusion】Different diets have different effects on the feeding,shell diameter growth,body weight growth,gonadal development and quality,and chon-droitin sulfate accumulation of S.intermedius,which can be effectively supplemented by feeding U.lactuca and G.verru-cosa during the period of S.japonica scarcity to ensure the growth and development of S.intermedius.