Nitrogen Output and Ecdysis in Crustacea

Abstract

IT has been observed¹ that nitrogen output in the shore crab, Carcinides, is very low prior to moulting, but begins to increase over the last few days. An indication that it rises sharply after ecdysis has now been confirmed in Asellus aquaticus (Fig. 1). Feeding individuals were isolated in 2 ml. of water at 23 ± 0.5° C.; the water was renewed daily, and its content of ammonia and amino-nitrogen (as in Carcinides the predominant nitrogen-compounds excreted) was estimated by a micro-adaptation of the Sørensen method. Estimates were monitored by the use of Russell's phenate–hypochlorite method².