斑石鲷早期发育的异速生长模式

Allometric growth pattern during early ontogeny of spotted knifejaw(Oplegnathus punctatus)

为研究斑石鲷（Oplegnathus punctatus）早期发育阶段的生长规律及重要器官的异速生长模式，作者运用实验生态学方法，测定了斑石鲷仔稚幼鱼（0~70日龄）全长和体质量随日龄的变化规律。结果显示，全长、体质量与日龄的关系均符合Cubic函数，随日龄的生长曲线表现为 S型。斑石鲷全长和体质量的生长可分为3个阶段，不同阶段的生长率存在显著差异（P＆lt;0.05）。斑石鲷的头长、眼径、吻长、口裂、体高、尾鳍长等重要外部形态学指标均存在异速生长规律，其生长拐点依次为35日龄（全长20.32 mm）、22日龄（全长13.17 mm）、29日龄（全长16.63 mm）、30日龄（全长15.50 mm）、32日龄（全长19.79 mm）、32日龄（全长19.79 mm）。相对于全长，头长、吻长、口裂在拐点前后由正异速生长变为等速生长；眼径、尾鳍由正异速生长转为负异速生长；而体高在0~70日龄为正异速生长，但拐点之后已明显变缓。研究表明斑石鲷通过异速生长，确保与其基本生存能力相关的功能器官优先发育，以适应复杂多变的生存环境，并相应地提高了仔稚鱼的存活率，对鱼苗培育具有重要的指导意义。

Early ontogenesis of spotted knifejaw （Oplegnathus punctatus） was investigated using morphology and morphometrics to study the allometric growth pattern. Spotted knifejaw were reared at （24 ＆#177; 0.3）℃ from hatching to 70 days post-hatching （d）, and total length, body weight, and allometric growth of important organs were deter-mined. Therefore, the increases in the total length and body weight were consistent with the cubic function and dis-played an S-curve with three distinct stages. Allometric growth patterns were detected between different organs （head, mouth, eyes, and fins） and total length and featured inflection points. The growth characteristics of the head length （with an inflection point at 35 d）, rostrum length （29 d）, and mouth width （30 d） changed from positive al-lometry to isometry around the infection points, whereas eye diameter （22 d） and tail fin length （32 d） changed from positive to negative allometry. Body height （32 d） maintained positive allometric growth during 0–70 d, with a dis-tinctly lower growth rate after the reflection point than that before. These results indicate that the spotted knifejaw develop the most important organs using an allometric strategy primarily to adjust themselves to the surroundings and achieve a higher survival rate.