Abstract 27 How to cite the abstract: Berger H. (2003): Uroleptopsis Kahl, 1932 (Ciliophora), a valid pseudokeronopsid genus. - International Conference on the Molecular Biology and Biotechnology of Ciliates and Anaerobic Protozoa in connection with 22nd Annual Meeting of the German Society for Protozoology, March 4-8, 2003 in Nijmegen, The Netherlands, Abstract on p. 49. BERGER Helmut Uroleptopsis Kahl, 1932 (Ciliophora), a valid pseudokeronopsid genus Consulting Engineering Office for Ecology, Radetzkystrasse 10, 5020 Salzburg, Austria. Website: http://www.protozoology.com; e-mail: office@protozoology.com Uroleptopsis was established by Kahl (1932; Tierwelt Dtl., 25, p. 543) because the lack of transverse cirri in some species prevailed their classification in Keronopsis (now Pseudokeronopsis). Kahl described one new species, the type U. citrina, and transferred two species to Uroleptopsis. The genus was accepted until 1983, when Borror and Wicklow (Acta Protozool., 22, p. 123) have put the type species into the synonymy of Pseudokeronopsis rubra. Borror argued – however, without evidence – that some P. rubra populations also lack transverse cirri so that the presence or absence of these cirri cannot be used to define groups. Mihailowitsch and Wilbert (1990; Arch. Protistenk., 138, p. 214) described P. ignea which lacks transverse cirri. Thus, Foissner (1995; Arch. Protistenk., 145, p. 64) transferred it to Uroleptopsis. However, this resurrection by Foissner was not accepted by Eigner (2001; J. Eukaryot. Microbiol., 48, p. 73). In spring 2002 I found a hypotrich which very closely resembles U. citrina, inter alia, in that it lacks transverse cirri and a buccal cirrus. The presence or absence of distinct cirral groups is widely used to define genera/subgenera. Thus, Uroleptopsis can be characterised as pseudokeronopsid with "lacking transverse cirri" as autapomorphy. The pseudokeronopsids (Thigmokeronopsis (Pseudokeronopsis, Uroleptopsis)) are defined by the many macronuclear nodules which do not fuse to a single mass prior to division and the formation of a new adoral zone for the proter right of the parental zone. The autapomorphy of Thigmokeronopsis is a conspicuous thigmotactic cirral field. Pseudokeronopsis and Uroleptopsis are likely united by the presence of conspicuous blood corpuscle-shaped structures (mitochondria?) near the cell surface. Supported by the FWF, Vienna, Project P14778-BIO ("Monograph of the urostylids"). Links Homepage www.protozoology.com Publication list of Helmut Berger Publisher Helmut Berger Main publication to this topic Keywords: Ciliophora, Hypotrichia, Italy, marine biology, Adriatic Sea, Mediterranean Sea, morphogenesis, phylogeny, Plesiouroleptopsis, Keronopsis, Pseudokeronopsis, Thigmokeronopsis, macronucleus, revision, Urostyloidea, Review, Pseudokeronopsidae, Pseudokeronopsinae, neotypification, nomenclature, cell division, ontogenesis, evolution, Duna Verde, Adria, Mittelmeer, Caorle, Ziliaten, Wimpertierchen, ciliates, Hypotricha, Hypotrichida, Stichotrichia, Stichotrichida, stichotrichs, Spirotrichea, Spirotricha, Top Dr Helmut BERGER Consulting Engineering Office for Ecology - Technisches Büro für Ökologie Radetzkystrasse 10, 5020 Salzburg, Austria, Europe Phone +43-(0)662-432538; Fax +43-(0)662-443139; email office@protozoology.com; http://www.protozoology.com