In P. ochraceus there is a significant, although not substantial, increase in ammonia in the
coelomic fluid during aerial exposure . However, both season and starvation play an important role in nitrogenous excretion in this species. Normally P. ochraceus excrete less than 10% of their
wastes as urea, but starved animals in the summer become ureotelic, excreting over 50% of their wastes as urea . This seems a likely explanation for the inability to detect significantwaste accumulation as ammonia in the present study.