Digestive Rates of Marine Invertebrates

Abstract

Two methods of approach were employed. One was to keep the animal in filtered sea water until the faeces were no longer passed, then give it normal or acceptable food and time the appearance of the faeces. A second method, the one normally used, was to introduce powdered carmine along with the food and check the time of its appearance in the faeces. The latter method worked well with voracious and generally rapid moving aggressive animals such as crabs, certain annelids, octopi and the like whose appetite seemed little effected by new and possibly uncongenial surroundings. But with the passive, non-aggressive forms whose chief response to adverse conditions was withdrawal into a shell, burrow or contracted condition, the first method or a combination of the two was resorted to.