Meeting Abstract

18.1  Monday, Jan. 4  The influence of temperature on courtship timing and incubation period in fiddler crabs (Uca) KERR, K.*; CHRISTY, J.; GUICHARD, F.; COLLIN, R.; LUQUE, J.; JOLY-LOPEZ, Z.; McGill University, Montreal and Smithsonian Tropical Research Institute (STRI), Panama; STRI, Panama; McGill University, Montreal; STRI, Panama and McGill University, Montreal; STRI, Panama and University of Montreal; McGill University, Montreal kecia.kerr@mail.mcgill.ca

Many tropical marine organisms have marked reproductive cycles that are repeated throughout the year, spanning considerable variation in sea temperature. Several species time the release of planktonic larvae to coincide with nocturnal large amplitude tides thereby promoting larval survival through their avoidance of diurnal predators. In the face of temperature-dependent egg development period, organisms must make adjustments to maintain reproductive timing optimal for reproductive success. We studied the relationship between temperature and courtship timing, and temperature and incubation period, in the fiddler crabs Uca terpsichores and U. deichmanni in Panama across seasonal upwelling-driven temperature changes. Preliminary results indicate U. terpsichores courts earlier when temperature decreases, while for U. deichmanni, a relationship between courtship timing and temperature is not evident. Incubation period in the field differed significantly between species and seasons. In contrast, in preliminary lab experiments, incubation period differed significantly between temperature treatments, however there was no significant difference in incubation periods between the species. Ovigerous U.deichmanni may behaviourally regulate incubation temperature, and thus incubation period, by moving up and down within their burrows. These differing responses to variable temperature may provide the two species with differing abilities to maintain timing of larval release during variable upwelling conditions and changing climate.