Assessing the Impact of Elevated Temperatures on Caribbean King Crab Physiology 

Gillian Smith, Taylor Queen, Jason Spadaro, Philip Gravinese
Eckerd College, Marine Science Discipline

Warmer temperatures have caused declines in Florida's coral reefs resulting in greater macroalgal cover. The grazing activity of Caribbean king crabs has made them attractive to coral restoration efforts yet no studies have determined their tolerance to the same thermal stress facing corals. We determined how thermal stress impacts the physiology of ovigerous king crabs at two temperatures: 28°C and 32°C. Hemolymph was collected at: 1, 5, and 10 days exposure to thermal stress and measured for lactate and protein serum. Crab stress levels were determined using a righting test. Closed respirometry was used to monitor metabolic rates after 7 days of exposure. Crabs in 32°C had higher lactate and protein levels consuming 37% more oxygen than at 28°C. Crabs at 32°C also took longer to right themselves. Our results suggest that thermal extremes cause sublethal physiological stress but low mortality indicates the species can tolerate acute anaerobic metabolism which may be beneficial for coral restoration efforts.