Morphological description of digestive tube of Sphoeroides testudineus (Linneaus, 1758) (Tetraodontidae)

Abstract

Fishes represent a group with great biodiversity in aquatic ecosystems. Teleosts have shown considerable food versatility throughout development, even within the same species. The morphology of the digestive tract (DT) of fishes concerns the ecology of their feeding habits, determining, then, its functionality. The fishes of the order Perciformes present two families, Tetraodontidae and Diodontidae, being represented by pufferfish. These fishes have the ability to expand the body cavity through water ingestion or inhalation of air, in an attempt to protect against predation. The species Sphoeroides testudineus (Tetraodontidae) occurs throughout much of the Atlantic coast of the American continent and it has great importance to the trophic diet of several species of marine animals, and their diet is generally composed of decapod crustaceans and mollusks. Thus, in view of the evolutionary characteristics of the pufferfish to adapt to the environment, this paper aims to describe the morphology of the digestive tract of a species of the Tetraodontidae family. For this purpose, it will be used 10 adult specimens of S. testudineus from fishing in the coastal region of Santos. After collection, the fish will be fixed with 10% aqueous formaldehyde, and TD segments will be identified, isolated, and used for the processing of light microscopy. Later sections of 5¼m thickness will be stained by the technique of hematoxylin and eosin (HE) and Masson Trichrome and examined under an optical microscope.(AU)