Abstract
Abstract
The nematode Comephoronema oschmarini Trofimenko, 1974 (Cystidicolidae) was found in the stomach of the burbot Lota lota (Linnaeus) of Lake Geneva, Savoy, France, collected on 23 March 2000 [prevalence 60% (3/5); intensity of infection 2–66 (mean 35)]. This material made it possible to study in detail the morphology of this so far little-known parasite, using both light and scanning electron microscopy (the latter not previously used for this species). The SEM examination showed taxonomically important morphological features, not previously reported, including the presence of distinct terminal pseudolabial projections (protuberances), four submedian labia, four bilobed submedian sublabia, and only four cephalic papillae. Deirids were found to be bifurcated. A description of the true arrangement of the two last pairs of minute caudal papillae and phasmids in the male is given. Species of Compehoronema Layman, 1933 are considered to be closely related to those of Ascarophis van Beneden, 1871. A key to valid species of Comephoronema is provided.