宽口光唇鱼胚胎发育的研究

OBSERVATIONS ON EMBROYNIC DEVELOPMENT OF ACROSSOCHEILUS (A.) MONTICOLA (G■NTHER)

在涪江下游宽口光唇鱼的产卵时间为4—5月,自然产卵水温为17℃—23℃。产卵场位于底质为卵石和砾石的浅水滩,分散产卵,卵弱粘性,金黄色,沉性,卵径1.55—2.11mm,卵膜外径2.27-2.55mm。在水温19.5—21.2℃条件下,胚胎从受精到孵化出膜共历时56h30min,初孵仔鱼全长6.0-6.2mm,肛后长/全长=24.14％,卵黄囊前部为膨大的球形,后部为均匀的棒状。

Spawning period of Acrossocheilus (A.) monticola is from April to May when the nature water temperature is between 17 and 23℃ in the lower reaches of the Fujiang River. The spawning individuals scatter at pebbly and sandy shoals, where the velocity of flow is slow. The matured eggs are slightly sticky and demersal. Color of the eggs is golden yellow. The size of eggs ranges from 1. 55 to 2.11mm in diameter, and that of egg-membrane from 2.27 to 2. 55mm in diameter. At the temperature of 19.5 - 21.2℃ , the incubation lasts about 56h30min. The total length of newly hatched larvae ranges from 6.0 to 6. 2mm. The length between anus and the end of body to total length is 24. 14% . The fore part of yolk sac expands into global shape and the hind part looks like a bar.