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The role of gape‐limitation in intraguild predation between endangered M ohave tui chub and non‐native western mosquitofish
Author(s) -
Henkanaththegedara Sujan M.,
Stockwell Craig A.
Publication year - 2013
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2012.00587.x
Subject(s) - mosquitofish , predation , gambusia , biology , endangered species , ecology , introduced species , context (archaeology) , zoology , fishery , habitat , paleontology , fish <actinopterygii>
Intraguild predation ( IGP ) is a mechanism that may facilitate the co‐existence of native species with non‐native invasive species. We conducted laboratory predation trials to assess the role of predator gape‐limitation in the context of IGP between the endangered M ohave tui chub ( S iphateles bicolor mohavensis ) and invasive western mosquitofish ( G ambusia affinis ). Larval tui chubs had significantly lower (χ 2 = 74.74; P < 0.001) survival in the presence of female mosquitofish (10.0%) than in the presence of male mosquitofish (73.3%). Reciprocally, adult tui chubs preyed upon adult mosquitofish, causing a significantly lower (χ 2 = 11.33; P < 0.001) survival for male mosquitofish (60%) compared to female mosquitofish survival (96.7%). Vulnerability modelling revealed that mosquitofish with a body depth < 4.6 mm and a larval tui chub with a body depth < 1.2 mm were completely vulnerable to predation by adult Mohave tui chub and adult mosquitofish, respectively. IGP in this study system is size‐structured based on gape‐size limitation and may have some conservation implications for the recovery of endangered M ohave tui chub. Our findings also provide an important caveat to the dogmatic view of mosquitofish as a threat whenever they invade. It is important to note that many previous studies that reported negative impacts of mosquitofish involved native species with relatively small body sizes, often the same size as mosquitofish.