Larval Mosquitoes as Vulnerable Prey: Chaoborus Predation
| Autor: | J. C. Helgen |
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| Rok vydání: | 1989 |
| Předmět: | |
| Zdroj: | Canadian Journal of Fisheries and Aquatic Sciences. 46:1642-1650 |
| ISSN: | 1205-7533 0706-652X |
| DOI: | 10.1139/f89-209 |
| Popis: | The vulnerability of instar I and II larvae of the mosquito Aedes vexans as prey for Chaoborus americanus is much greater than that of the small coexisting prey, Daphnia pulex. Predation on Aedes larvae could reduce Aedes populations in overlapping habitats, and be a selective force in driving Aedes to lay eggs in muds of more temporary wetlands. Predation rates are great (7–25∙d−1) and ingestion times are rapid (0.8–6 s) on Aedes instars I and II. In prey choice experiments, Chaoborus strongly prefers Aedes I over small Daphnia. An Aedes diet promotes growth of Chaoborus at least as well as a Daphnia diet. Larval Aedes behaviors show a distinct difference between the first two and last two instars. Aedes swimming speeds and swimming distances increase with each instar, but when disturbed, the first two instars significantly reduce their swimming distances. Calculated prey vulnerabilities, based on swimming speeds and reciprocal ingestion times, suggest a much greater vulnerability for Aedes I and II than that for small (0.8 mm) Daphnia or for Aedes III and IV (4.6–6.2 mm). |
| Databáze: | OpenAIRE |
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