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Predation of a cave fish ( Poecilia mexicana , Poeciliidae) by a giant water‐bug ( Belostoma , Belostomatidae) in a Mexican sulphur cave
Author(s) -
TOBLER MICHAEL,
SCHLUPP INGO,
PLATH MARTIN
Publication year - 2007
Publication title -
ecological entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0307-6946
DOI - 10.1111/j.1365-2311.2007.00892.x
Subject(s) - cave , predation , biology , predator , population , ecology , demography , sociology
1. Caves are often assumed to be predator‐free environments for cave fishes. This has been proposed to be a potential benefit of colonising these otherwise harsh environments. In order to test this hypothesis, the predator–prey interaction of a belostomatid (predator) and a cave fish (prey) occurring in the Cueva del Azufre (Tabasco, Mexico) was investigated with two separate experiments. 2. In one experiment, individual Belostoma were given a chance to prey on a cave fish, the cave form of the Atlantic molly ( Poecilia mexicana ), to estimate feeding rates and size‐specific prey preferences of the predator. In the other experiment, population density of Belostoma was estimated using a mark–recapture analysis in one of the cave chambers. 3. Belostomatids were found to heavily prey on cave mollies and to exhibit a prey preference for large fish. The mark–recapture analysis revealed a high population density of the heteropterans in the cave. 4. The absence of predators in caves is not a general habitat feature for cave fishes. None the less predation regimes differ strikingly between epigean and hypogean habitats. The prey preference of Belostoma indicates that cave‐dwelling P. mexicana experience size‐specific predation pressure comparable with surface populations, which may have implications for life‐history evolution in this cave fish.