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Bio-diversity of fish communities in Lake Tanganyika

坦噶尼喀湖鱼类群落的生物多样性

基本信息

批准号：
10041178
负责人：
KOHDA Masanori
金额：
$ 11.39万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

During the project period, field research on fish communities in Lake Tanganyika has been conducted as was planned. The fish census on the permanent quadrat gave further evidence on the stability where fish fauna, fish species and even the number of each species were quite similar not only during the study period but also the previous studies. Several field experiments conducted in rocky shores indicated that artificial disturbance on local fish had weak effect on the fauna. Artificial rocky bases made in shallow sandy bottom were colonized by several cichlids that were not restricted in rocky habitat, suggesting that long sandy beaches can operate geographical barriers on the distribution of rock dwelling fishes.Cichlids in this lake have laterality in body morph, and it is hypothesized that the frequency of laterality in fish of the same feeding groups fluctuates with 5-year cycle. The results of this project seemed to support the hypothesis, and the obtained data will indicate that prey-predator relationship will result in the fluctuation. Namely, minority advantage operate in this phenomenon : minor morph of a fish species receive less predation pressure than fish of majority morph.Reproductive ecologies on some littoral fishes have been conducted, including cichlids and catfishes. Biparetal care in catfishes, coorepative polyandry in a cichlid, piracy mating in monogamous substrater as analternative male mating tactic, have been revealed.

在项目期间，按计划对坦噶尼喀湖的鱼类群落进行了实地研究。永久样方的鱼类普查进一步证明了稳定性，不仅在研究期间，而且在以前的研究中，鱼类区系、鱼类种类甚至每个种类的数量都非常相似。在岩石海岸进行的几个野外实验表明，对当地鱼类的人为干扰对动物区系的影响很小。在浅的桑迪底上建造的人工岩石基地中，有几种不局限于岩石栖息地的慈鲷类定居，这表明长的桑迪海滩可以对岩栖鱼类的分布产生地理障碍。该湖泊中的慈鲷类具有身体形态的偏侧性，并且推测同一摄食群体的鱼类的偏侧性频率以5年为周期波动。本研究的结果似乎支持这一假设，所获得的数据将表明捕食者-被捕食者关系将导致波动。即少数优势在这一现象中起作用：一种鱼类的少数形态比多数形态的鱼类受到更小的捕食压力。鲶鱼的双配偶照顾，慈鲷的合作一妻多夫制，一夫一妻制基质中的海盗交配作为另一种雄性交配策略，已经被揭示出来。