哲罗鱼仔稚鱼嗅囊发育及其与摄食强度的关系

为掌握哲罗鱼Hucho taimen仔稚鱼嗅囊的发育过程及其与摄食强度的关系,对哲罗鱼仔稚鱼嗅囊发育进行了组织形态学观察,研究了嗅囊发育与摄食强度之间的对应关系,描述了各发育时期的时序和形态特征。结果表明:初孵哲罗鱼仔鱼嗅囊上皮未分化,消化道未有食物充塞度;25~26日龄仔鱼仅有少数个体(11.1%)消化道有一定的食物充塞度(1级);27日龄仔鱼多数个体(占66.7%)开始少量摄食,此时嗅囊上皮仍未分化;29日龄仔鱼均摄食,消化道食物充塞度达到2级和3级的个体分别占44.4%和33.3%;30日龄仔鱼嗅囊上皮从嗅囊基部开始分化;42日龄稚鱼上皮分化更加明显,细胞分化加剧,此时嗅囊上皮分化;45日龄稚鱼均强烈摄食,消化道食物充塞度等级均达到5级,此时嗅囊上皮分化完成;55日龄稚鱼嗅囊形成第一个初级嗅板;85日龄稚鱼嗅囊分化完成,通过光镜和电镜观察,嗅上皮细胞可分为6类,即基细胞、支持细胞、纤毛非感觉细胞、纤毛感觉细胞、柱状细胞和黏液细胞。本研究结果可为哲罗鱼资源的保护和苗种培育提供理论依据。

Correlation between feeding intensity and development of olfactory sac in larval and early juvenile taimen Hucho taimen

Development of olfactory sac was observed and described in larval and early juvenile taimen Hucho taimen under a light microscope and electron microscope ( scanning electron microscope and transmission electron microscope) to know the relationship between development of olfactory sac and feeding intensity. The undifferenti-ated epithelia of olfactory sac and devoid of food were found in the digestive tract in the newly hatched larvae. Few individuals (11. 1%) showed initial feeding 25-26 days post hatching ( DPH) and the fullness rank of digestive tracts was in degree 1, and most individuals (66. 7%) appeared to begin to feed at 27 DPH, but the epithelia of olfactory sac were still undifferentiated. All individuals had active feed, with fullness rank of 2 (44. 4%) and 3 (33. 3%) in digestive tract at 29 DAH. The initial differentiation of olfactory sac was observed at 30 DPH, obvi-ously differentiated epithelia of olfactory sac were occurred at 42 DPH, and the well developed epithelia of olfactory sac were appeared, with fullness rank of 5 in the digestive tract at 45 DPH. The first primary lamellae were formed at 55 DPH and the olfactory sac was differentiated well at 85 DPH. The cells of olfactory epithelium were divided into six categories:basal cells, supporting cells, ciliated non-sensory cells, ciliated receptor cells, rod cells and goblet cells by the light microscopy and the transmission electron microscopy. The findings provide a theoretical ba-sis for the protection and breeding of taimen.