Histological development of digestive tract of the Caspian salmon, Salmo trutta caspius, from hatching to 6 month post-hatching was studied using light microscope. The digestive tract of newly hatched larvae was a simple, undifferentiated tube which continued from mouth to anus. In 10 days post hatching larvae, the alimentary canal became more differentiated and secretion was started activity, ...

Avian infectious bronchitis (IB) is a major cause of economic losses in poultry industry. The IB virus primarily affects respiratory tract, but various strains differ in their tropism for other target organs such as kidney and alimentary tract. The objective of this study was to estimate the pathogenicity of Iranian IBV variant (IR-1), which is limited exclusively to Iran. Specific pathogen fre...