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Abstract
Aim:
The aim of the present study was to estimate the probable impact of predation
of the exotic snail Anentome helena on two co-occurring freshwater
snails, Racesina luteola and Physella acuta, in the laboratory
set-up.
Methodology: In the initial experiment, the predatory efficiency
of A. helena was observed using R. luteola and P. acuta
as prey, separately, under varying prey and predator densities. In the
following experiment, the prey snails were provided in both conspecific and
heterospecific conditions with different predator densities to deduce the
prey preference of A. helena, if any.
Results:
The experiments show that A. helena can consume a considerable number
of R. luteola and P. acuta. The predation rate of A. helena
varied significantly (p< 0.0001) with different sizes of prey, prey and
predator densities. Although the predation rate differed among conspecific
and heterospecific prey conditions, A. helena did not demonstrate any
significant prey preference towards any of the prey.
Interpretation: The study revealed that the chance
dispersal of predator A. helena from household aquaria to natural
habitats may directly impact the population of the freshwater snail R.
luteola and P. acuta.
Key words: Assassin snail, Aquatic snail, Invasive snail, Physella
acuta, Prey preference
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