A Correlation Between Pituitary and Integumentary Structure in the Nine-Spined Stickleback,Pungitius pungitius L.

Benjamin, M. 1980. A correlation between pituitary and integumentary structure in the nine-spined stickleback, Pungitius pungitius L. (Department of Anatomy, University College, Cardiff, Wales, U.K.) — Acta zool. (Stockh.) 61(2): 105–109. Naturally occurring, large pituitary cysts, that almost excluded prolactin cells from the pituitary of Pungitius pungitius L., offered a unique opportunity to study a target organ for prolactin (the integument) in fish that were “partially hypophysectomised” without any accompanying surgical trauma. In fish with large pituitary cysts, the epidermis from the lateral body wall was thinner and its mucocytes less abundant, than in fish with normal pituitaries and thus many prolactin cells. In support of the hypothesis that prolactin produced the observed integumentary changes, was the similarity of other pituitary cells in animals with and without cysts. Evidently, prolactin can influence the integument of Pungitius, even though it does not seem essential for freshwater survival.