Tuno Nobuko, Miki Kaori, Minakawa Noboru, Githeko Andrew, Yan Guiyun, Takagi Masahiro
Department of Vector Ecology and Environment, Institute of Tropical Medicine, Nagasaki, University, Nagasaki, Japan.
J Med Entomol. 2004 Jul;41(4):810-2. doi: 10.1603/0022-2585-41.4.810.
Anopheles gambiae Giles larvae usually live near the surface of shallow and temporary aquatic habitats. How deep the larvae can dive and how long they can submerge may be related to feeding efficiency and predator avoidance. This study examined diving behavior of An. gambiae larvae in the laboratory. We recorded diving depths and larval mortality of second and fourth instars in clean water and muddy water by using deep water (32-cm) and shallow water (20-cm) columns. In deep water columns with clean water, we found that 2% of second instars and 6% of fourth instars died from diving, whereas 3% of second instars and 11% of fourth instars died in muddy water. The fourth instars dived deeper in muddy water than in clean water. The mortality rates of the fourth instars subjected to diving stimulations were significantly higher than those in the shallow water columns. Therefore, larval diving behavior may offer the benefits of predator avoidance and food acquisition but also incur energetic costs and increased mortality.
冈比亚按蚊幼虫通常生活在浅的临时水生栖息地表面附近。幼虫能潜多深以及能在水下停留多长时间可能与摄食效率和躲避捕食者有关。本研究在实验室中检测了冈比亚按蚊幼虫的潜水行为。我们通过使用深水（32厘米）和浅水（20厘米）柱，记录了清洁水和浑水中二龄和四龄幼虫的潜水深度和幼虫死亡率。在装有清洁水的深水柱中，我们发现2%的二龄幼虫和6%的四龄幼虫因潜水死亡，而在浑水中，3%的二龄幼虫和11%的四龄幼虫死亡。四龄幼虫在浑水中比在清洁水中潜得更深。受到潜水刺激的四龄幼虫的死亡率显著高于浅水柱中的死亡率。因此，幼虫的潜水行为可能带来躲避捕食者和获取食物的好处，但也会产生能量消耗并增加死亡率。
