Cryptocotyle concavum (Creplin, 1825) Lühe, 1899

This species of Cryptocotyle was named "concavum” for its concave body shape. A synonym is Cryptocotyle echinata (Linstow, 1878) for this first species of Cryptocotyle to be described. Specimens have been collected from birds in Europe, North Africa, and in North America. The flukes are found in the small intestine and are about 1 mm long with an oval body containing vitellaria which extend anteriorly to a mid-point between the ventral sucker and the bifurcation of the intestine. The eggs are 34 to 38 µm long by 16 to 20 µm in width. It has been shown that cats can be infected if they are fed infected fish (Issaitschikoff IM, Weinberg M. 1926. Sue le dévelopment du trematode Cryptocotyleconcavum (Crepl.). Comptes Rendu Soc Biol 94:305-308.).