Ultrastructural and Histopathological Studies of the Digenetic Trematode <i>Siphodera Ghanensis</i> (Cryptogonimidae), Parasite of <i>Chrysichthys Nigrodigitatus</i> (Lacepede, 1802) from Lekki Lagoon, Lagos, Nigeria

Abstract

Specimens of Chrysichthys nigrodigitatus (Bagridae) (n= 528) were procured between October 2008 and June 2010 from Lekki Lagoon, Lagos, Nigeria. Siphodera ghanensis was recovered from (53.6%) of the fish specimens. SEM observations revealed the length of the trematode as 1.670 mm and the breadth as 625μm. The oral sucker is circular with a distance of 629μm to the ventral sucker. The ventral sucker has a length of 135μm and a breadth of 197μm and lies in a pit like cavity. This study revealed that the ventral sucker is not centrally placed on the body. The tegument of the cryptogonimid trematode is characterised with some markings and whitish ornamentations. The cephalic and the body region bears some compressed alae. The parasite has the distome body plan of digenetic trematode. The histopathology of the parasitized gastrointestinal tracts revealed necrosis of intestinal surface epithelium, hyperplasia of villi, accumulation of inflammatory debris within lumen and calcification within the tunica muscularis. This is the first report of the description of the trematode with SEM in Nigeria. The study provides a complete morphological details of the cryptogonimid trematode.

Keywords: Cryptogonimidae, distome, Siphodera, hyperplasia, Chrysichthys nigrodigitatus

Nigerian Journal of Parasitology, Vol. 33 [1] March 2012, pp. 103-109