Ref ID : 7628
Walter Sudhaus; [Rhabditis dimorpha: Ein Beispiel fur unvollstandige Hautung und Sexualdimorphismus bei Nematoden] (Rhabditis dimorpha: An Example for Imperfect Ecdysis and Sexual Dimorphism in Nematodes). Zool.Anz.,Jena 199(5/6):325-352, 1977
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Rhabditis dimorpha Sudhaus, 1976 (Rhabditidae) is described and figured in detail, and information is given concerning its ecology and biology. Sickle-shaped cirri at the lips of the females (not the male) and the retention of the cuticle of the last larval stage in the adults are peculiar. Comparison of the 5 closely related species of the Rhabditis-Curvicaudata-group shows that they are almost identical in the structure of bursa and spicules and that they differ mainly in structures important for nourishment such as lips and stoma. In the same region the sexual dimorphic character is expressed. Some morphological specialities as the outgrowths (cirri) at the lips of the female, borders in the stoma, teeth of the metarhabdions and a pocket-like spermatheca joining the uterus are discussed, likewise the retention of the old cuticle after the last molt. Such an imperfect ecdysis is found in some related species belonging to the subgenera Cephaloboides and Diploscapteroides of Rhabditis, but otherwise only in one species of Rhabditis. Moreover two cuticles are known from the typical dauerlarvae of the Secernentia, in a sexual dimorphic manner from the phytophagous Hemicycliophora and the entoparasitic Tetleyus, and possibly they are also characteristic for the Myolaimidae. It is discussed, how the completion of ecdysis is stopped and the vulva is opened, furthermore different aspects of biological advantages of the duplicate cuticle and the sexual dimorphism in relation to different ecological roles of the sexes. - A new name is proposed: Myolaimus rahmi nom. nov. for Cephalobus bursifer Rahm, 1928.