TY - JOUR

T1 - 'Leaves and eats shoots'

T2 - direct terrestrial feeding can supplement invasive red swamp crayfish in times of need

AU - Grey, Jonathan

AU - Jackson, Michelle C

PY - 2012/8/3

Y1 - 2012/8/3

N2 - We used stable isotope analyses to characterise the feeding dynamics of a population of red swamp crayfish in Lake Naivasha, Kenya, after the crash of submerged macrophytes and associated macroinvertebrates, and during a natural draw-down of the lake water level. We expected a heavy reliance upon a diet of detrital matter to sustain the population as a consequence, and indeed, for the majority of the crayfish population caught from the lake, we saw a concomitant shift in isotopic values reflecting a dietary change. However, we also caught individual crayfish that had occupied the footprints of hippopotamus and effectively extended their range beyond the lake up to 40 m into the riparian zone. Isotopic analysis confirmed limited nocturnal observations that these individuals were consuming living terrestrial plants in the vicinity of the footprints. These are the first empirical data to demonstrate direct use of terrestrial resources by an aquatic crayfish species and further highlight the traits that make red swamp crayfish such opportunistic and successful invaders.

AB - We used stable isotope analyses to characterise the feeding dynamics of a population of red swamp crayfish in Lake Naivasha, Kenya, after the crash of submerged macrophytes and associated macroinvertebrates, and during a natural draw-down of the lake water level. We expected a heavy reliance upon a diet of detrital matter to sustain the population as a consequence, and indeed, for the majority of the crayfish population caught from the lake, we saw a concomitant shift in isotopic values reflecting a dietary change. However, we also caught individual crayfish that had occupied the footprints of hippopotamus and effectively extended their range beyond the lake up to 40 m into the riparian zone. Isotopic analysis confirmed limited nocturnal observations that these individuals were consuming living terrestrial plants in the vicinity of the footprints. These are the first empirical data to demonstrate direct use of terrestrial resources by an aquatic crayfish species and further highlight the traits that make red swamp crayfish such opportunistic and successful invaders.

KW - Crayfish

KW - Lakes

KW - Swamps

KW - Stable isotopes

KW - Ecological niches

KW - Invasive species

KW - Invertebrates

KW - Surface water

U2 - 10.1371/journal.pone.0042575

DO - 10.1371/journal.pone.0042575

M3 - Journal article

VL - 7

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 8

M1 - e42575

ER -