LUCIONEMA BALATONENSE GEN. ET SP. N., A NEW NEMATODE OF A NEW FAMILY LUCIONEMATIDAE FAM. N. (DRACUNCULOIDEA) FROM THE SWIMBLADDER OF THE EUROPEAN PIKEPERCH, STIZOSTEDION-LUCIOPERCA (PISCES)

A new nematode genus and species, Lucionema balatonense gen. et sp. n. , is described from the swimbladder of the European pikeperch, Stizost edion lucioperca (L.), from Lake Balaton in Hungary; a new dracunculoi d family Lucionematidae fam. n. is established to accommodate it. The hitherto monotypic family Lucionematidae shows affinities with the fam ilies Skrjabillanidae and Daniconematidae, differing from them mainly in having simple oesophagus without external oesophageal glands and th e vulva situated near the middle of body; from the first family also i n the absence of the buccal capsule and the bursa-like caudal alae in the male. The genus Lucionema gen. n. is characterized mainly by the p resence of 8 cephalic papillae in two circlets, absence of spicules, p resence of the copulatory plate, only 2 pairs of postanal papillae in the male, and by the distal part of the monodelphic uterus forming a p osteriorly directed coil. The body length of L. balatonense females is 1074-1782 mu m, that of the only available male 770 mu m. A key to th e families of the Dracunculoidea is presented.