河川沙塘鳢早期鳞被的形成

Early Scale Development in the Dark Sleeper Odontobutis Potamophita(Gunther)

利用实验室培育的河川沙塘鳢稚鱼，对其早期鳞被的形成过程进行了详细观察。鳞片首先出现于孵化后２２天的稚鱼，全长８．８６～１０．４９ｍｍ；孵化后４４天，全长１４．６０～１４．９６ｍｍ时，鳞被发育完全。鳞被形成的起始中心位于第二背鳍后部与臀鳍后部之间的体例中线处，鳞域由此中心向全身扩展。当群被发育完全时，鱼体除吻端和头部腹面无鳞片、头部和下腹部为圆鳞外，均为栉鳞覆盖。

Early development of squamation in the dark sleeper (Odontobutis potamephila)was observed in detail, based on the juvenile reared in the laboratory.Scales first occurred in juvenile 22days after hatching at a Size of 8. 86～10. 49mm (TL. ).The body was completely covered with scales when the fish were 14. 60～14. 96mm 44 days after hatching. The only center of the first scales to appear was at the horizontal line of the drunk between the posterior part of the second dorsal fin and the posterior part of anal fin,the scales spread in all directions from the only center.When the early scale had completely developed,there were cycloid scales on the head and on the belly,there were ctenoid scales on the other places.