Rangeland Ecology & Management

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Comparison of Gila topminnow and western mosquitofish as biological control agents of mosquitoes
Author
Childs, Michael R.
Publisher
Monte L. Bean Life Science Museum, Brigham Young University
Publication Year
2006
Body

I compared acute tolerance of Gila topminnow, Poeciliopsis occidentalis , and western mosquitofish, Gambusia affinis , to ammonia and high water temperature and also compared diet, food selectivity, and impact on invertebrate populations to evaluate the potential for each species to effectively control mosquitoes (Culicidae) in wetland habitats. Critical thermal maxima differed among species, sexes, and lifestages, but these differences were likely not biologically significant due to their small magnitude and the ability of wild populations of both species to adapt to high temperatures. In 24-hour tests, G. affinis displayed about twice the ammonia tolerance as did P. occidentalis . However, long-term survival in habitats with high ammonia concentrations is questionable, thus reducing the perceived benefit of using G. affinis for mosquito abatement in these habitats. Diet overlap was significant between sexes within species but was not significant between species. However, both species exhibited significant dietary selection for mosquito larvae and pupae under experimental conditions. Shared dietary preference for mosquito larvae and pupae, in addition to similarity in temperature tolerance between species, suggests that P. occidentalis , a native and historically widespread species, can be used in place of nonnative G. affinis for mosquito control. There is no evidence to suggest that nonnative G. affinis is better suited for mosquito abatement, and since G. affinis is replacing P. occidentalis throughout the native species' former range, it should no longer be introduced into the Gila River basin for mosquito control. However, managers who would use P. occidentalis for mosquito abatement must take care not to interfere with conservation efforts by disrupting the genetic structure of natural populations of P. occidentalis . [AUTHOR ABSTRACT]

Language
English
Resource Type
Text
Document Type
Journal Issue/Article
Journal Volume
66
Journal Number
2
Journal Pages
181-190
Journal Name
Western North American Naturalist
Keywords
Arizona
Gambusia affins
Gila topminnow
Poeciliopsis occidentalis
United States