Histology of the digestive system of Phoxinellus pseudalepidotus (Teleostei: Cyprinidae), an endemic and endangered species from Mostarsko blato (Neretva river basin, Bosnia and Herzegovina)

Eight specimens of the species Phoxinellus pseudalepidotus (Bogutskaya & Zupančič, 2003) were sampled to study the morphology of the digestive system. Hematoxylin-eosin staining was used in order to elucidate the histological features of the digestive organs in P. pseudalepidotus. P. pseudalepidotus is a stomachless fish whose digestive system is a hollow tube made of esophagus and intestines. The esophagus consists of three distinctive layers: the mucosa, the muscular layer and the outer layer. The esophageal epithelium contains abundant goblet cells. All observed parts of the intestines consisted of three-layered wall containing mucosa, muscular layer and outer layer. The liver as an associated digestive gland consists of the anastomosing plates of hepatocytes separated by sinusoidal capillaries. The results show that the histology of the digestive system in P. pseudalepidotus is congruent with its feeding habits.