Assessments during shell exchanges by the hermit crabClibanarius vittatus: the complete negotiator

1996 Animal Behaviour  
The behaviour of the hermit crab Clibanarius vittatus was studied as it investigated shells prior to and during shell exchange interactions. Crabs behaved in a manner predicted by the negotiations model of resource exchange, that is, shells were primarily exchanged between crabs when both crabs benefited in shell fit from the exchange. During initial investigation of shells, crabs in poorly fitting shells selected shells that (1) were similar to the preferred shell size of the investigating
more » ... and (2) that did not fit their current occupant well. In addition, the greater the shell deficit (deviation from that crab's preferred shell size) of the other crab, the more likely it was investigated by a crab in a poorly fitting shell. Considering three factors (initiator's preferred shell size, current shell deficit of the non-initiator and magnitude of gain possible for the non-initiator) explained 86% (multiple r=0.93) of the variance in shells rapped by initiating crabs. In those interactions that proceeded to rapping behaviour, the magnitude of gain in shell fit that the non-initiating crab would experience if a shell exchange occurred helped explain which shells were selected for rapping. The relative size of the two crabs was only important in the assessment and decisions process once rapping began, and the number of raps was inversely proportional to the relative size difference of the crabs.
doi:10.1006/anbe.1996.0060 fatcat:qh73t7ykfbhcnfilrn3rirebz4