Anatomy of finfish and shellfish

Unit 9 - Endocrine system

9.1. Introduction
The vertebrate endocrine system is present in it essence already in Lampreys and Hag fishes,further similarities with higher vertebrates appear in both the shark and bony fishes. Fishes possess a well developed endocrine system comparable to that of other vertebrate .The recent demonstration of tissue with parathyroid like function (Rasquin and Rosenbloom 1954) has filled a gap formerly thought to exist in the list of fish endocrine organs. Major contributions in the fish endocrine have also been made in studies of physiology of migration (Fontain,1954,Oliverean 1954)and reproduction (Bretsch-neider,Wit 1947,Docid 1955,Hoar,1957). Important Endocrine Glands in Fishes.

Following are important endocrine glands found in fishes

• Pituitary gland.
• Thyroid gland.
• Chromaffin tissue (Supra renal body, medullary tissue represent the adrenal).
• Interrenal tissue (Adrenocortical tissue).
• Gonads.
• Ultimobranchial tissue.
• Intestinal mucosa.

Following are main tissue with possible endocrine function:

• Carpuscles of stanius.
• Pineal organ.
• Thymus
• Urohypophysis
• Pseudobranches.