情況下，其全長(zhǎng)增加速率隨日齡的增加呈逐漸上升趨勢(shì)。隨著軍曹魚仔魚全長(zhǎng)的增長(zhǎng)，其口徑增加速率越高，其中最小和最大口徑對(duì)應(yīng)的全長(zhǎng)分別為4.087和6.351 mm。在軍曹魚的頭部器官中，吻長(zhǎng)、口寬和頭高在仔魚發(fā)育階段表現(xiàn)為正異速生長(zhǎng)，眼徑則表現(xiàn)為等速生長(zhǎng);在軀干部中，頭長(zhǎng)和尾長(zhǎng)在仔魚發(fā)育階段為正異速生長(zhǎng)，體高為等速生長(zhǎng)，軀干長(zhǎng)為負(fù)異速生長(zhǎng);在游泳器官中，軍曹魚胸鰭在仔魚發(fā)育階段保持正異速生長(zhǎng)，尾鰭則為負(fù)異速生長(zhǎng)。【結(jié)論】軍曹魚仔魚發(fā)育階段優(yōu)先發(fā)育游泳器官和攝食器官，以增強(qiáng)其追逐及捕食能力，為生長(zhǎng)發(fā)育提供餌料保障，保證營(yíng)養(yǎng)充足，適應(yīng)外界環(huán)境，進(jìn)而提高仔魚存活率。
關(guān)鍵詞： 軍曹魚;仔魚;異速生長(zhǎng);早期發(fā)育
中圖分類號(hào)： S965.399 文獻(xiàn)標(biāo)志碼：A 文章編號(hào)：2095-1191（2018）11-2320-07
Allometric growth of Rachycentron canadum larvae
JIANG Min-tian1，2， ZHOU Sheng-jie2，3， HU Jing2， YANG Rui2， MA Zhen-hua2，
MENG Xiang-jun3， SU Sheng-qi1*
（1School of Animal Science and Technology， Southwest University， Chongqing 400715， China; 2Tropical Fisheries Research and Development Center， South China Sea Fisheries Research Institute， Chinese Academy of Fishery Sciences， Sanya， Hainan 572018， China; 3Sansha Meiji Fishery Development Co.， Ltd.， Haikou 570110， China）.
Abstract：【Objective】The priority of organ development and growth rates at different development stages in the early development process of Rachycentron canadum larvae were studied. The basic biological data of the development process could be improved to provide theoretical basis for the breeding and healthy aquaculture of the R. canadum.【Method】The morphological indexes were used to measure R. canadum individual total length， head length， rostrum length， mouth width eye diameter， head height， body height， trunk length， tail length， pectoral length and tail fin length. Then early allometric growth model of R. canadum larvae was researched systematically combining with the regression equation of the fitting method. It included allometric growth of organs in the head， swimming organ and trunk. 【Result】The regression equation of the relationship between the full length of R. canadum larvae and the age of day was y=3.8912e0.0388x（R2=0.9623）， under the normal feeding condition of R. canadum， the growth rate of the full length increased gradually with the age of day. With the increase of the total length of R. canadum larvae， the increase rate of mouth gape was higher， and the corresponding length of the minimum and maximum mouth gapes were 4.087 and 6.351 mm respectively. As for the major head organs， rostrum length， mouth width and head height exhibited positive allometric growth in larval development stage. Eye diameter exhibited the constant speed growth. In the parts of the trunk， the head length and tail length presented positive allometric growth， body height exhibited the constant speed growth， and trunk length presented negative allometric growth. As for the swimming organs， the pectoral fin of the R. canadum kept positive allometric growth while caudal fin was in negative allometric growth. 【Conclusion】In R. canadum larvae development stage， the priority is to develop swimming organs and feeding organs to enhance its pursuit and predation ability，ensure sufficient nutrition， adapt to the environment and improve the survival rate of the larvae.