Reproductive processes of scyphidiid peritrichs associated with limpet and haliotid hosts along the coast of South Africa

[摘要] English: During the early 19th century a lot of progress was made in clarifying reproductionpatterns and cycles in the kingdom Protozoa Goldfuss, 1818. During the first half ofthe 20th century various scientists studied the reproductive processes of peritrichs andmade valuable contributions. While thousands of recent papers exist on reproductionof ciliates, not much work has been done on epibiontic peritrichs. In this study theprocesses of binary fission, telotroch formation and conjugation are described forMantoscyphidia branchi Van As, Basson & Van As, 1998, M. marioni Van As, Basson& Van As, 1998, M. midae Botes, Basson & Van As, 2001 and M. spadiceae Botes,Basson & Van As, 2001. It was also determined whether binary fission, telotrochformation and conjugation occur in a new species of Ellbiophrya Peters, Van As,Basson & Van As, in prep. Haliotids were collected from 1997 to 2002 at the De HoopNature Reserve on the south coast of South Africa and were also obtained from theDanger Point Abalone Farm near Gansbaai, and the Abagold Farm in Hermanus.Limpets were collected from 1993 to 2002 from the Goukamma Nature Reserve, DeHoop Nature Reserve and Keurboom Beach on the south coast; Mc Dougall's Bay andthe Olifants River Mouth on the west coast; Bazley and at the rocky shores of Lake St.Lucia on the east coast of South Africa; and on the east coast of Marion Island atBoulder Beach which is situated in the southern Indian Ocean. Live symbiontspecimens undergoing reproduction were observed with light microscopy andphotomicrographs were taken of the various stages of binary fission, conjugation andtelotroch formation. Mayer's, Harris' and Heidenhain's Iron Hematoxylin were used tostain the nuclear apparatus. The details of the infundibulum were studied by stainingBouin's fixed smears with protargol. Gills were also examined using scanning electronmicroscopy. Binary fission was mostly observed in M. spadiceae and also occurredearlier in M. spadiceae than in M. branchi and M. midae populations. The formation oftelotrochs was mostly observed in populations of M. branchi and M. spadiceae.Throughout this study it was uncertain whether binary fission always has to occurbefore a telotroch can develop, or whether binary fission follows telotroch formation.Conjugation was mostly observed in populations of M. branchi and M. midae. In theEllobiophrya species conjugation was also observed and this is the first record ofconjugation in the genus Ellobiophrya (Chatton & Lwoff, 1923). It would be possible tostudy all these processes in detail if a suitable medium could be cultured in future.

[发布机构] University of the Free State