白条双锯鱼胚胎及仔稚鱼发育形态学观察

【目的】观察记录白条双锯鱼从受精到孵化的胚胎发育及早期个体发育规律，为海葵鱼的人工繁育提供科学依据。【方法】以人工海水为养殖用水，在水温（27±1）℃、盐度27‰的条件下，白条双锯鱼自然产卵，经紫外灯照射杀菌后进行人工孵化及仔稚鱼培育，在显微镜下定期观察记录受精卵及仔稚鱼发育过程的形态特征变化，并手绘制图。【结果】白条双锯鱼受精卵整体上呈长条状，橙红或粉红色，轮廓类似葫芦状的椭圆形，长径2.40~2.60mm、短径0.90~1.20mm。依据受精卵的分裂、分化及发育形态，可将白条双锯鱼胚胎发育过程划分为:卵裂前期、卵裂期、囊胚期、原肠期、神经胚期、体节期、翻转期、血管形成期和器官形成期。白条双锯鱼受精卵经8~10 d的孵化时间破膜，初孵仔鱼体长4.10~4.50mm；孵出第1d即可开口摄食轮虫，孵出后7d左右由仔鱼期进入稚鱼期，尾鳍、臀鳍和背鳍彼此分离，此时的体长达7.67±0.48mm；至孵化后第20d开始出现第一道白色条纹；孵化后第30d仔稚鱼体色由黑色转为暗红色，并开始长出第二道白色条纹；从孵化后第50 d第二道白色条纹开始褪去；至孵化后第60d其体色开始转为红色。【结论】白条双锯鱼胚体发育时间为8~10d，相较于双锯鱼属其他品种需要更长的孵化时间，究其原因是白条双锯鱼受精卵尺寸更大。此外，孵化环境温度对受精卵的发育时间有明显影响，在适当范围内，环境温度越高白条双锯鱼受精卵发育速度越快。白条双锯鱼仔稚鱼饲养宜分为3个阶段喂养不同类型的饵料，以保证仔稚鱼的高成活率。

Morphologic observation on embryonic and larval development of Amphiprion frenatus

【Objective】Observed and recorded the embryonic development and early ontogenesis of Amphiprion frenatus from fertilization to hatching，to provide scientific basis for artificial breeding of anemonefish.【Method】Artificial seawater was used for aquaculture，anemonefish spawned at（27±1）℃，and in the salinity of 27‰ conditions. Artificially hatching and breeding larval and juvenile after the aquaculture water was sterilized by ultraviolet lamp. Morphological changes of zygote and larval and juvenile during development were observed regularly under a microscope and the images were freehand sketched.【Result】The fertilized eggs of A. frenatus were long strips，orange-red or pink，with a gourd-like oval shape in outline，with a long diameter of 2.40-2.60 mm and a short diameter of 0.90-1.20 mm. According to the division，differentiation and developmental morphology of the zygote，the embryonic development of A. frenatus could be divided into following stages:precleavage stage，cleavage stage，blastocyst stage，gastrum stage，neuroembryo stage，segmental stage，turnover stage，angiogenesis stage and organogenesis stage. It took 8-10 days for the zygote to develop and break its egg membrane. The length of the newly hatched A. frenatus was 4.10-4.50 mm. On the first day after hatching， they could open their mouths to take food. They took about 7 d to develop from larva stage to juvenile stage. The caudal， anal and dorsal fins were separated from each other and the body length at this time reached 7.67±0.48 mm. The first white stripe appeared on the 20 d after incubation. On the 30 d after hatching，the body color of juvenile fish changed from black to dark red and began to grow a second white stripe. From 50 d after hatching，the second white stripe began to fade. On the 60 d after incubation，its body color began to turn red.【Conclusion】The actual development time of the embryo body is 8-10 d，which is longer than that of other species belonging to Amphiprion. The reason is that the fertilized eggs of the A. frenatus are larger in size. In addition，the incubation environment temperature has influence on the development time of fertilized eggs，and the higher the ambient temperature is，the faster fertilized eggs of A. frenatus develop. The feeding of larval and juvenile of A. frenatus can be divided into three stages by feeding different types of bait to ensure the high survival rate of larval and juvenile.