绿鳍马面鲀早期生长发育与摄食特性的研究

在人工培育条件下,采用实验生态学方法,对绿鳍马面鲀(Thamnaconus modestus)仔、稚、幼鱼生长、发育与摄食特性的变化进行了研究。结果表明,绿鳍马面鲀仔、稚、幼鱼的各生长指标可拟合为具有1~2个生长转折点的2~3段直线,其中全长、体长、体质量、肛前长、头长、吻长和体高可拟合为3段直线,眼径可拟合为2段直线。头长在第一转折点后的生长速率显著高于其他指标,除头长和体高在第二个生长转折点后生长速率减慢外,其余各项生长指标生长速度均逐渐加快。3~4日龄“开口期”前后的仔鱼,摄食发生率和饱食率均较低,随后逐渐升高。摄食发生率在12日龄后达到100%,饱食率在25日龄后达到100%(消化道充塞度为3~4级)。绿鳍马面鲀仔、稚、幼鱼均为白天摄食类型,白天摄食量占全天摄食量的71.6%以上。随日龄增长,鱼苗饱食时间呈下降趋势,消化时间则呈上升趋势。了解绿鳍马面鲀早期的生长发育与摄食特性,可为人工育苗管理提供参考,以促进鱼苗生长,提高成活率。

Growth, development, and feeding characteristics of Tham-naconus modestus during early stages

We investigated the adoption of experimental ecology methods, changes in growth, development and feeding characteristics of larval, juvenile, and young Thamnaconus modestus under artificial rearing conditions. Results revealed that the growth indexes of larval, juvenile, and young T.modestus fits into 2 or 3 straight lines, with 1 or 2 inflection points including the total length, body length, body weight, pre-anal length, head length, snout length, body depth (which can be fitted in 3 segments), and eye diameter (which can be fitted in 2 segments). The growth rate of head length was significantly higher than that of other indexes, especially at the first inflection point. However, the growth rate of head length and body depth declined after the second inflection point, while the growth rates of all other growth indexes accelerated gradually. In the "feeding initiation stage", although the feeding incidence and satiation rate of 3dph and 4dph larval were initially lower, they increased gradually overtime. The feeding incidence and the satiation rate reached 100% at 12dph and 25dph (where the fullness degrees were all of level 3 and 4). The larval, juvenile, and young T.modestus represented the daytime feeding habit, which accounted for more than 71.6% of daily ration. With an increasing growth, the fullness time of the fry followed an overall declining trend, while the digestion time followed an overall elevating trend. The growth, development and feeding characteristics of T.modestus during early stages offers a good reference to the manager of artificial rearing for promotion of growth and survival of fry.