Redescription of Pseudolepidapedon balistis Manter, 1940 and a biological variant (Trematoda: Acanthocolpidae) from the Red Sea fishes; Balistoides viridescens and Rhinecanthus assasi.

During a survey of Red Sea fish parasites, two trematodes belonging to the genus Pseudolepidapedon Yamaguti, 1938 were encountered: P. balistis Manter, 1940 was found in the small intestine of the fish Balistoides viridescens and was redescribed for the first time from Egypt; adding many detailed morphological and ultrastructural characters. The second trematode was found in the small intestine of the fish Rhinecanthus assasi and found to represent a biological variant of the previous species as it differs from it in its generally smaller dimensions, shape of suckers and pharynx and the testes. SEM details of the first species were described for the first time illustrating the differences in the spination and papillae on different parts of the body; which may be of taxonomic importance in recognizing future different species of the genus.