A revision of the Suctoria (Ciliophora, Kinetofragminophora) 4. Podophrya and its morphological relatives Colin R. Curds Zoology Department, British Museum (Natural History), Cromwell Road, London SW7 5BD Contents Introduction 59 Genus Podophrya 59 Genus Parapodophrya 82 Genus Mucophrya 87 References 88 Index to species 91 Introduction The species of the two well-known genera Podophrya Ehrenberg, 1833 and Sphaerophrya Claparede and Lachmann, 1859 and the two lesser known Parapodophrya Kahl, 1931 and Mucophrya Gajewskaja, 1933 are the subjects for consideration in this the fourth part of the series. It will immediately be noticed that the genus Sphaerophrya has here been treated as a synonym of Podophrya. The two genera were originally distinguished by the presence of a stalk in Podophrya and the absence of one in Sphaerophrya. However it has long been known that the stalk is often lost by several species of Podophrya and apparently some Sphaerophrya species occasionally develop one. The presence of a cyst with a stalk has also been used as a distinguish-ing character but it should be appreciated that this is based on few observations and a similar stage may yet be found in Sphaerophrya. Another possible method of distinguishing the two genera investigated by the present author was based on the observation that the ciliary rows in Podophrya species are arranged transversely while those in many traditional Sphaerophrya species are arranged longitudinally. However examination of the description of bud formation in the type species Podophrya fixa Ehrenberg, 1833 by Penard (1920) clearly shows that while the kinetics are initially transverse they become longitudinally orientated as the bud elongates. It is clear therefore that there is no stable character by which to distinguish the two genera and under such circumstances they must be synonymised, indeed Corliss (1979) indicated that such a step might be necessary in his taxonomic review of the ciliates. Genus PODOPHRYA Ehrenberg, 1833 Sphaerophrya Claparede and Lachmann, 1 859 Kystopus Jankowski, 1967 The morphology of Podophrya is simple in comparison to many other suctoria and several features indicate that they could be regarded as primitive. Most are simple spheres with an even distribution of capitate tentacles radiating out from the body. Some are without a stalk and float freely in the water while others are attached by means of a stalk to vegetation and inanimate objects, only rarely are they found attached to aquatic arthropods. Several species have become endo-or ectoparasites of ciliated protozoa and in some cases the species may only be dis-tinguished by its association with a particular host. However, it should be noted that the degree Bull. Br. Mus. nal. Hist. (Zool.) 50(2): 59-91 Issued 26 June 1986
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