MCCALL, S.*; LOWDER, A.; QUACKENBUSH, L.S.: Temperature effects molting of juvenile blue crabs, Callinectes sapidus.

Blue crab megalopa invade estauries and molt to the first crab stage in spring and summer in North Carolina. Growth rates in warm shallow waters will dictate when these crabs can move out of the juvenile habitats. We investigated the effects of salinity on growth rates and previously reported that crabs molt equally well in salinities from 5 to 30 0/00. This project investigated the effect of water temperature (23,25,27,30 degrees centigrade)on molting and growth of juvenile ( 10-40 mm) blue crabs. Mean molt cycle durations for the crabs in the 4 temperature treatments were not significantly different for those crabs that molted. Intermolt durations averaged about 20 days for all treatments. However, crabs maintained at 30 degrees molted more often than crabs at lower temperatures. Crabs maintained at 23 degrees molted once or twice, whereas crabs at 30 degrees molted 3 or 4 times. At the North Carloina collection site, water temperature in the summer ranges from 26-32 degrees. Crabs at these temperatures would molt every 15-20 days. Funded by NSF : DBI 99:7863, Cooperative Research at Undergrauate Institutions. See: uncwil.edu/bio/crui.