...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>oecologia >Population regulation of a tropical damselfly in the larval stage by food limitation, cannibalism, intraguild predation and habitat drying
【24h】

Population regulation of a tropical damselfly in the larval stage by food limitation, cannibalism, intraguild predation and habitat drying

机译：

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The relative importance of intraspecific, interspecific, and seasonal causes of larval mortality were investigated for aquatic larvae of the giant damselflyMegaloprepus coerulatusin Panama. These larvae live in water-filled holes in fallen and living trees, where they and three other common odonate species are the top predators. By mid wet season,M. coerulatuslarvae were found in nearly half of all tree holes that harbored odonates. AlthoughM. coerulatuswere typically, but not always, eliminated from holes inhabited by larger hetero-specifics,M. coerulatuswere more likely to encounter conspecifics than other odonate species. Hole with less than 11 of water rarely contained more than a single larva. In large holes whereM. coerulatuswas the only odonate species present, multiple larvae coexisted at a density of one larva per 1–21 of water. There the absence of 2–4 of the 5 larval size classes, despite a continuous input of eggs, suggested that cannibalism was a common cause of mortality. The size of the final instar, which determined adult body size, was correlated positively with tree hole volume for male, but not female, larvae. Experiments showed that when two larvae were placed together in 0.4–1 holes with abundant tadpole prey, the larger larva killed the smaller one. Often the larva that was killed was not eaten. Small larvae were more tolerant of each other than were pairs of medium or large larvae. Before killing occurred, the presence of larger larvae reduced the growth of smaller individuals, relative to controls. ‘Obligate’ killing was density-dependent. In 3.0–1 holes with ad libitum prey, conspecific killing occurred until the larval density stabilized at one larva per 1–1.5 I, similar to the density found in large holes under field conditions, ForM. coerulatus, cannibalism functions to reduce the number of potential competitors for food in addition to providing nutrition. When interactions between paired larvae in small holes were experimentally prevented, competition for food reduced the growth of one or both larvae relative to controls. Holes that were watered during the dry season supported larval densities similar to those in the wet season. Thus, dry season mortality could not be attributed to a decrease in available prey. Rather,M. coerulatuslarvae could not survive more than 1 month of complete drying. Because the dry season typically lasts more than 6 weeks, habitat drying is a secondary source of mortality, affecting second- or third-generation larvae that fail to emerge before tree holes dry o

著录项

  • 来源
    《oecologia》 |1994年第1期|118-127|共页
  • 作者

    OlaM.Fincke;

  • 作者单位

    Smithsonian Tropical Research Institute;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 英语
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号