The effects of prey type and prey preparation on the mathematical form
s and rates describing gastric evacuation in little skate Raja erinace
a were examined. Linear and square-root models best described the gast
ric evacuation of whole, thin-shelled krill Meganyctiphanes norvegica,
clam feet/muscle Spisula solidissimal/Placopecten magellanicus, polyc
haetes Glycera spp. and sand lance Ammodytes dubius. Evacuation of kri
ll and clams was faster than polychaetes and sand lance. A logistic mo
del best described the evacuation data of thick-shelled benthic shrimp
Crangon septemspinosa/Palaemonetes spp. Cut polychaetes Nereis spp, w
ere digested at an exponential rate and were evacuated faster than wou
ld be predicted based upon comparison with live polychaetes and previo
usly published evacuation-temperature relationships. The results of th
is study suggest that a single equation does not describe the evacuati
on process for all prey, and that whole prey should be used if laborat
ory-derived rates of gastric evacuation are to reflect what might occu
r in wild fishes.