Transcript Interspecific differences in fiddler crab feeding rates.

WALLACE RESOURCE LIBRARY
Module 03 – Animal Behaviour
D02 – Interspecific differences in fiddler crab
feeding rates.
Introduction to fiddler crabs
• Fiddler crabs are small intertidal crustaceans and usually have
one very large claw.
• Fiddlers are active on mudflats at low tide where they feed on
detritus, algae and bacteria.
• During high tide they live in burrows.
• There are lots of different species feeding together on the
mud and this study looks at the differences between the
species in how they feed.
• The mudflats studied are in Indonesia
Research Questions
• Do feeding rates differ between species
• Do feeding rates differ among the same species living
at different tidal heights?
Methods
• Three species of fiddler crab are observed at 2
different heights along horizontal transects above
the low tide mark.
• 10 individuals from each species are studied by
observing individuals through binoculras whilst they
feed.
• The number of times each crab scooped up sediment
into their mouths during 30 seconds was recorded.
Discussion?
1.
The data suggests that each species of fiddler crab
has its own rate of feeding. This rate might be
related to the time it spends out of water and its
tolerance to desiccation and over-heating.
2.
Further analysis shows that within a species, the
rate of feeding differs for different heights of the
beach above the low tide level – reasons for this
are considered.