Histology of the digestive system of the garfish Belone belone (Teleostei: Belonidae)

Abstract

Five garfish Belone belone (Linnaeus, 1761) were sampled to study the morphology of the digestive system. Hematoxylin-eosin staining as well as Alcian blue/PAS (Periodic Acid Schiff) were used in order to elucidate the histological features of the digestive organs in garfish. Garfish B. belone is a stomachless fish whose digestive system is a hollow tube made of oesophagus and intestines. The oesophagus consists of three distinctive layers: the mucosa, the muscular layer and the outer layer. The oesophageal epithelium contains abundant goblet cells. All three observed parts (anterior, middle and posterior) of the intestines consisted of four-layered wall containing muscosa, submucosa, muscular layer and outer layer. The liver as an associated digestive gland also contains some pancreatic tissue spread out through the liver parenchyma. The results show that the histology of the digestive system in garfish is congruent with its feeding habits.