The Radiation Sensitivities of Three Species of Fiddler Crabs (Uca pugilator, U. pugnax, and U. minax)

Abstract

The radiation sensitivities of five estuarine decapod crustacea were compared: three species of fiddler crabs,Uca pugilator, U. pugnax, U. minax: the blue crab,Callinectes sapidus, and the grass shrimp,Palaemonetes pugio. Temperature and salinity (20 C and 30 o/oo) and radiation dose rate (310 rad/min) were the same for all species. The 40-day LD-50 values for the fiddler crabs (U. pugilator, 9,800 rad;U. pugnax, 16,500 rad; andU. minax, 13,500 rad) fell between those of the blue crab, 42,000 rad, and grass shrimp, 215 rad. Possible physiological and ecological explanations for the differences in sensitivity are discussed.