双锯鱼属(Amphiprion)四种鱼种比较胚胎学研究和进化探讨

在严格控制水温和盐度条件下,对白条双锯鱼(Amphiprion frenatus)野生鱼、眼斑双锯鱼(A.ocellaris)野生鱼、海葵双锯鱼(A.percula)选育种和眼斑双锯鱼(A.ocellaris)选育种的胚胎发育进行观察比较。结果表明,所有双锯鱼几乎均稳定在一个月产卵两次,在相同的生长环境中,不同种类双锯鱼产卵时间相差不大,产卵间隔规律性较强;但胚胎发育时间有较大差别,海葵双锯鱼的选育种胚胎发育时间最长,眼斑双锯鱼的选育种最短。四种双锯鱼有着相同的胚胎发育学特征和孵化期,但胚胎发育时间不同,分别为244h、240h、260h、181h;其中卵裂期到神经胚期的发育时间差小于2h,翻转期至孵化期决定了胚胎发育时间。研究发现,不同双锯鱼胚胎发育时间可能与进化距离有关,且温度、光照周期以及卵质量与形态对其胚胎发育时间有较大影响。本研究的海葵双锯鱼选育种为纯人工选育的后代,在整个繁育过程中与野生种都有较大的差异。人工选育眼斑双锯鱼的胚胎发育时间最短,与野生眼斑双锯鱼差异明显。通过对不同双锯鱼比较胚胎学的研究可以丰富其人工选育技术,确定双锯鱼之间以及双锯鱼与其他鱼类的亲缘关系,为观赏鱼进化学说的发展和新品种选育提供依据。

STUDIES ON COMPARATIVE EMBRYOLOGY AND DISCUSSION OF EVOLUTIOLOGY IN FOUR VARIETIES OF AMPHIPRION

The embryonic development of Amphiprion frenatus, A. ocellaris, the A. percula of artificial breeding, and the A. ocellaris of artificial breeding are observed and compared under captive condition. The results show that the four varieties of Amphiprion almost all spawn twice monthly. The difference of spawning time is smaller and the regularity of spawning interval is relatively strong of all Amphiprion in the same breeding environment. However, there is significant difference of embryonic development time, in which the longest one is A. percula of artificial breeding and shortest one is A. ocellaris of artificial breeding. The four varieties of Amphiprion have same embryonic development characteristic and incubation period. But the embryonic development duration is different, they are 244h, 240h, 260h, and 181h, respectively. The developmental duration is difference between the cleavage stage and the neurula stage is less than 2h, the period from the turning phase to the hatching phase determines the embryonic development duration. This study indicates that the developmental duration of embryonic development in different Amphiprion may be related to the evolutionary distance. In addition, the temperature, photoperiod, quality and morphology of the eggs have a great influence on the embryonic development duration. In this study, the A. percula of artificial breeding (Picasso) is a purely artificial offspring which have a great difference with the wild. The embryonic developmental duration of the A. ocellaris of artificial breeding (Snowflake) is the shortest, which is significantly different from the wild A. ocellaris. This study can enrich the Amphiprion artificial breeding knowledge, determine the genetic relationship among the different Amphiprion and the genetic relationship between the Amphiprion and other fishes, moreover provide theoretical basis for the development of ornamental fish and the breeding of new varieties.