Impacts of mosquitofish,Gambusia affinis,on black mudfish,Neochanna diversus |
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| Authors: | Nicholas Ling Kate Willis |
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| Institution: | 1. Centre for Biodiversity and Ecology Research, Department of Biological Sciences , The University of Waikato , Private Bag 3105, Hamilton , New Zealand E-mail: nling@waikato.ac.nz;2. Centre for Biodiversity and Ecology Research, Department of Biological Sciences , The University of Waikato , Private Bag 3105, Hamilton , New Zealand;3. Dunstaffnage Marine Laboratory , Scottish Association for Marine Science , Oban, Argyll , PA37 1QA , Scotland |
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| Abstract: | The potential for western mosquitofish, Gambusia affinis, to negatively affect populations of black mudfish in New Zealand wetlands was investigated with annual fishing surveys of the Whangamarino wetland and by laboratory experiments evaluating competition and predation of mosquitofish on mudfish adults and larvae. Abundance of mudfish juveniles was reduced in the presence of mosquitofish at marginal wetland sites close to permanent water, but mosquitofish were not found at ephemeral adult mudfish habitats. In constructed wetland microcosms, mosquitofish reduced both growth and condition of post‐larval mudfish but did not attack or kill mudfish. In laboratory aquaria, mosquitofish rapidly consumed mudfish fry but survival time of the latter was significantly extended by an increase in density of submerged structures and by the presence of an alternative food source for mosquitofish. Because mosquitofish cannot survive in ephemeral wetlands that dry over summer, the impacts of mosquitofish on mudfish are likely to be minimal except in habitats where mosquitofish can survive year‐round owing to the presence of permanent standing water. |
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| Keywords: | Neochanna diversus black mudfish Gambusia affinis mosquitofish competition predation conservation |
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