Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 85. (Budapest 1993)

Nesemann, H.: Identification key to the Hungarian leeches of the subfamily Trochetinae Pawlowski, 1954, with notes on systematics of the subfamily Erpobdellinae Blanchard, 1894 (Hirudinea)

in XII cl0/d23 (or XII b5/c23). In contrast to these species, the distance of gonopores of T. subviridis is widened. The male gonopore is shifted posteriorly to somite XIII. The main differences in Trocheta can be found in the male genital system and the oral sucker, the position of the genital opening seems not so important for taxonomy as in the case of Dina. The atrium of Trocheta differs markedly. One of the most interesting form is that of T. cylindrica. Its atrium with non-coiled horns is extended from somite XII to XI instead of the ejaculatory ducts of other Trochetinae species (Figs 41-42). The same features are present in the western sister-species T. pseudodina Nesemann, 1990. In contrast, the atrium of T. riparia is extremely small and extended only on XII c2 to XII b2 (Figs 47-48). Pre-oral organization, pharynx and oral sucker All erpobdellid leeches have three remarkable pseudognaths. They are closed hyaline jaws without calcified teeth. The pseudognaths are situated in the pharyngeal folds of segment III. Caused by the strepsilaematous pharynx, two of them are in dorsolateral position (e.g. Fig. 11) and one is on the ventromedian fold. They play an important role in seizing the prey. The tips of the pseudognaths point in pharyngeal direction, whereby the prey can not escape from the oral sucker. The development of pseudognaths and oral sucker shows two interspecific phylogenetic lines: I. Carnivorous feeder of smaller and hemisessile prey (e.g. chironomids, Oligochaeta), suctoroid oral sucker (Fig. 9), small pseudognaths (Fig. 11) and short pre-oral segments (Erpobdellinae, Dina lineata). II. Carnivorous predator of large and active prey (e.g. leeches, lumbriculids), rostelloid oral sucker, large pseudognaths and occasional accessory pseudognaths (Figs 19, 27, 34, 40, 46). The pre-oral segments, prostomium and peristomium, are forming a muscular rostellum to grasp the food (Trochetinae). The first rostellum segment sometimes bears a number (30-50) of sensillae (Figs 7-8). Their function is not yet known, but they may be used for tasting or smelling. The intermediate status of Dina lineata Several morphological features were presented above to explain the differences between Erpobdella, Dina and Trocheta. Regarding the specialization of annulation as a line of evolution, the Trochetinae are originated from Erpobdellinae ancestors. The most plesiomorphic member of Trochetinae is Dina lineata with simply annulated somites and widened annulus b6 (Fig. 14). This leech shows a number of plesiomorphic features, therefore it takes place as a connecting link between Erpobdellinae and Trochetinae. The oral sucker is of suctoroid and Erpobdella-like, character, the pseudognaths are small and the pre-oral segments do not form a typical rostellum (Fig. 11). The atrium bears short and simply curved cornua (Figs 12-13). These might be caused by the habits, but, on the other hand, show the exceptional status of this species.