中华鲟吻部腹面罗伦氏囊结构与功能的研究

THE STRUCTURE AND FUNCTION OF THE AMPULLAE ON THE VENTRAL PART OF THE SNOUT OF CHINESE STURGEON (ACIPENSER SINENSIS GRAY)

于1993年12月-1994年9月，从宜昌葛洲坝工程总局中华鲟人工繁殖研究所获中华鲟实验材料128尾，通过扫描电镜（包括冷冻断裂扫描电镜）、透射电镜及行为学实验方法，研究中华鲟吻部腹面罗伦氏囊结构及其功能作用。结果表明，中华鲟吻部腹面存在大量罗伦氏囊。触须表面无罗伦氏囊而仅存在很少量味蕾。中华鲟罗伦氏囊由开孔、管道和壶腹三部分组成，壶腹具有梨形单纤毛电觉细胞。中华鲟对微弱电刺激异常敏感，且对较小电刺激物有摄食反应，而对水蛆蚓汁化学刺激则没有反应。为此可以认为中华鲟吻部腹面罗伦氏囊是电觉器官，在中华鳄觅食活动中起作用，而中华鲟触领味觉在觅食中作用不大。

Indoor tank investigations were made in December, 1993, on the structure and function of the ampullae on the ventral part of the snout of Chinesesturgeon (Acipenser sinensis Gray) collected from the Chinese Sturgeon ArtificialPropagation Research Institute (Yichang County, Hubei Province) by scanningand transmission electron microscopical examination and observing its response tovarious stimuli.The ventral part of the Chinese sturgeon's snout has numerous ampullae. Theampullary organs have a sensory cell very similar to that found in the Lorenalnianampulla, an electroreceptor found in marine Elasmobranchs. The sensory cells arepearshaped with single cilium on the center of their sharp ends.The conclusion that these organs are electroreceptors is supported by the findings that the fish responds to the introduction of an iron bar, whereas a plasticbar introduced in the same way causes no response. Chinese sturgeon was observed to bite an iron wire or to suck iron powders, but did not respond toTubifex worm juice, while live worms are natural food of the fish,Sturgeons feed on the bottom by sucking and are generally thought to detectfood by their barbels where very few taste buds are found. lt indicates that Chinese sturgeon may feed mainly by electroreception of the ampullae on theventral part of its snout, and that the gustatory sense of the barbels does not playan important role in feeding.