青石斑鱼视网膜运动反应的特性

CHARACTERS OF RETINOMOTOR RESPONSE IN THE RETINA OF BANDED GROUPER (EPINEPHELUS AWOARA)

1987年,在龙海及厦门附近海域采集青石斑鱼,以组织学方法进行视网膜运动反应特性研究,结果表明:(1)青石斑鱼视网膜运动反应几乎以线性方式进行,暗适应在75min内完成,至少有15min潜伏期,视锥肌样体伸长与色素上皮(REP)色素颗粒聚集的速率分别为2.2μm/min和2.7μm/min。明适应在15min内完成,没有潜伏期,视锥肌样体收缩与REP色素颗粒扩散速率分别为8.9μm/min和10.8/μm/min。(2)在持续黑暗和持续光照下,该鱼不产生节律性视网膜运动反应,表明视网膜运动反应主要受光控制,很少受到内源节律性系统影响,这与该鱼长期栖息于近海底层岩礁和洞穴昏暗环境,活动性弱相适应。

The characters of retinomotor response in the retina of banded grouper obtained from seawater in Xiamen and Longhai was inves+igated in 1987. The study included time course of retinomotor response and influence of endogenous rhythmic system on the retinomotor response. The results showed:(1)From light-to-dark adaptation, both elongation of cone myoids and aggregation of REP pigment granules exhibited a latent period of up to 15 minutes, and were completed in 75 minutes in darkness. It was found that elongation of cone myoids and aggregation of REP pigment granules occurred at linear rates of 2.2μm/min and 2.7μm/min respectively. The movements began immediately after dark-to-light transition in both REP and cones, and were completed in 15 min after illumination. The contraction of cone myoids and dispersion of REP pigment granules proceeded at linear rates of 8.9μm/min and 10.8μm/min respectively.(2)Under the period of both constant darkness and constant light, the fish did not show a circadian rhythm in the position of cone cells and REP. This may indicate retinomotor responses were mainly controlled by light, and slightly by an endogenous circadian rhythic system. It might be due to the rock crevice environment at the bottom of neritic zone where the fish lives with very little variation in light intensity and their inactive habit.