Chapter 7 - Endocrinology

Abstract

Crustaceans have been at the forefront of endocrinology since the early 20th century, with the discovery that pigmentation was under endocrine control, followed by the identification of the eyestalks with the X-organ/sinus gland complex as one of the major endocrine structures. The crustacean hyperglycaemic hormone (CHH) then received most research efforts, being identified as one of the major components released by the eyestalks and involved in the moulting process. In fact, the European green crab, Carcinus maenas, entered the picture as the first crustacean in which CHH was characterized. Work on this crab also substantially contributed to our understanding of hormone cascades involved in cardioventilatory function, (glucose) metabolism, reproduction, and osmoregulation, and how these endocrine processes are affected by changes in the crabs’ environment. With green crabs being one of the most successful invasive species of our time, however, more recent research efforts and insights as to how pollution and other endocrine-disrupting chemicals might affect these animals are mostly lacking. This chapter aims to summarize the endocrine findings in C. maenas to date, by summarizing the essential parts of the crustacean endocrine system (i.e. involved organs and hormones), explaining major physiological processes, and lastly, making the reader aware of current environmental challenges that might lead to endocrinological disruption in these animals.