不同海藻饲料对刺参幼参生长的影响

Effects of different seaweed diets on growth of juvenile sea cucumber Apostichopus japonicus

为了研究海藻饲料对刺参Apostichopus japonicus幼参生长效果的影响,在水温(18±1)℃下,将体质量(1.25±0.02)g的幼参饲养在容积为25 L的塑料水槽中,每槽6头,投喂采用孔石莼Ulva pertusa、角叉菜Chondrus ocellatus、裙带菜Undaria pinnatifida干粉及其混合干粉、鲜孔石莼、鲜角叉菜、鲜裙带菜及其混合磨碎液与25%海泥制成的8种饲料,共饲养60 d,试验结束时测定幼参的生长情况和水体中的氨氮含量。结果表明:投喂不同海藻饲料的幼参存活率均在80%以上,组间无显著性差异(P>0.05);投喂鲜孔石莼饲料的幼参体质量增长最快,特定生长率为(1.38±0.13)%/d,显著高于其他组(P<0.05);投喂鲜孔石莼饲料的幼参饲料转化率显著高于其他组(P<0.05),而其他组间无显著性差异(P>0.05),此组的摄食率和排粪率均为最高,且与其他组有显著性差异(P<0.05);鲜孔石莼组水体的平均氨氮含量最低,为(0.005±0.003)mg/L,孔石莼干粉组最高,为(0.021±0.016)mg/L,两者有显著性差异(P<0.05)。研究表明,投喂鲜孔石莼时幼参的生长效果最好,对水体的氨氮含量影响较小,在刺参幼参培育中添加鲜孔石莼效果较好。

Juvenile sea cucumber Apostichopus japonicas with body weight of （1. 25±0. 02）g was reared in a 25 L plastic tank at a rate of 6 individuals each tank and fed 8 diets containing various proportions of fresh seaweeds （ sea lettuce Ulva pertusa, chondrus Chondrus ocellatus, sea mustard Undaria pinnatifida） and powder and 25% sea mud for 60 days to evaluate the effects of different seaweed diets on the growth of sea cucumber juveniles at water temperature of （18±1）℃. Ammonia nitrogen level in water and growth were measured at the end of the feeding trial. The results showed that there were no significantly differences in survival rates （ over 80%） of sea cucumber fed different diets （P〉0. 05）. However, there were significant higher specific growth rate [（1. 38±0. 13）%/d] and food conversion efficiency in the sea cucumber juveniles fed fresh sea lettuce than those in the other diet groups （ P〈0 . 05 ） , without significantly differences in food conversion efficiency among the other diet groups （ P〉0 . 05 ） . There was the maximal food ingestion rate and fecal production rate in the sea cucumber fed fresh sea lettuce, significantly different from those in the sea cucumber fed other diets （P〈0. 05 ）. At the end of the experiment, there was the minimal ammonia nitrogen concentration [（0. 005±0. 003）mg/L] in the water where the sea cucumber juveniles fed fresh sea lettuce were reared, and there was the maxima ammonia nitrogen concentration [（0. 021 ± 0. 016）mg/L] in the water where the sea cucumber juveniles fed sea lettuce powder were reared, with significant difference between them （P〈0. 05）. The findings indicate that the sea cucumber juveniles have good growth, and the ammonia nitrogen concentration in the water is kept low when they are fed fresh sea lettuce.