Morphological, Histological and Histochemical Analysis of the Digestive Tract in Panga Pangasius hypophthalmus (Teleostei: Siluriformes).

The current study aims to describe the macroscopic, histological and histochemical features of the digestive tract of omnivorous fish species Panga Pangasius hypophthalmus-which derives from Southeast Asian watersheds-with emphasis on secretory cell types and their histochemical reactions. Results have evidenced that the anatomical organisation of the digestive tract in the coelomic cavity of the investigated species is similar to that of other omnivorous teleosts, except for a pneumatic duct linking the distal portion of their oesophagus to their swim bladder. It is worth highlighting that both the oesophagus and the stomach have well-developed histological layers and that the stomach has a saccular shape and is highly distensible to ensure longer food storage time.

First report of Trichodinella and new geographical records of trichodinids in Nile tilapia (Oreochromis niloticus) farmed in Brazil.

Massive occurrence of trichodinids is frequently accompanied by serious disease in fish farms. In this study, trichodinid species from the gills and skin of Nile tilapia (Oreochromis niloticus) farmed in the central-western region of Brazil (state of Goiás) were morphologically characterized. Dried slides were prepared from the parasites and were impregnated with silver nitrate (2%).