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

Abstract

English: During the early 19th century a lot of progress was made in clarifying reproduction patterns and cycles in the kingdom Protozoa Goldfuss, 1818. During the first half of the 20th century various scientists studied the reproductive processes of peritrichs and made valuable contributions. While thousands of recent papers exist on reproduction of ciliates, not much work has been done on epibiontic peritrichs. In this study the processes of binary fission, telotroch formation and conjugation are described for Mantoscyphidia 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, telotroch formation 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 Hoop Nature Reserve on the south coast of South Africa and were also obtained from the Danger Point Abalone Farm near Gansbaai, and the Abagold Farm in Hermanus. Limpets were collected from 1993 to 2002 from the Goukamma Nature Reserve, De Hoop Nature Reserve and Keurboom Beach on the south coast; Mc Dougall's Bay and the 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 at Boulder Beach which is situated in the southern Indian Ocean. Live symbiont specimens undergoing reproduction were observed with light microscopy and photomicrographs were taken of the various stages of binary fission, conjugation and telotroch formation. Mayer's, Harris' and Heidenhain's Iron Hematoxylin were used to stain the nuclear apparatus. The details of the infundibulum were studied by staining Bouin's fixed smears with protargol. Gills were also examined using scanning electron microscopy. Binary fission was mostly observed in M. spadiceae and also occurred earlier in M. spadiceae than in M. branchi and M. midae populations. The formation of telotrochs was mostly observed in populations of M. branchi and M. spadiceae. Throughout this study it was uncertain whether binary fission always has to occur before a telotroch can develop, or whether binary fission follows telotroch formation. Conjugation was mostly observed in populations of M. branchi and M. midae. In the Ellobiophrya species conjugation was also observed and this is the first record of conjugation in the genus Ellobiophrya (Chatton & Lwoff, 1923). It would be possible to study all these processes in detail if a suitable medium could be cultured in future.

Afrikaans: Gedurende die vroeë 19de eeu is baie vooruitgang in die verklaring van voortplantings patrone en siklusse in die koninkryk Protozoa Goldfuss, 1818 gemaak. Gedurende die eerste helfte van die 20ste eeu het verskeie wetenskaplikes die voortplantings prosesse van die verteenwoordigers van die Peritrichia Stein, 1859 bestudeer en waardevolle bydraes gelewer. Alhoewel daar duisende onlangse wetenskaplike publikasies bestaan oor voortplanting in siliate, is daar nie veel werk op verteenwoordigers van epibiontiese Peritrichia gedoen nie. In hierdie studie word die prosesse van tweedeling, telotrogvorming en konjugasie vir Mantoscyphidia branchi Van As, Basson & Van As, 1998, M. marioni Van As, Basson & Van As, 1998, M. midae Botes, Basson & Van As, 2001 en M. spadiceae Botes, Basson & Van As, 2001 beskryf. Tydens die studie is daar ook bepaal of tweedeling, telotrogvorming en konjugasie in 'n nuwe spesie van Ellbiophrya Peters, Van As, Basson & Van As, in voorbereiding voorkom. Perlemoen is vanaf 1997 tot 2002 by die De Hoop Natuurreservaat langs die suidkus van Suid Afrika en ook vanaf die Danger Point perlemoenplaas naby Gansbaai en die Abagold perlemoenplaas in Hermanus versamel. Klipmossels is vanaf 1993 tot 2002 by die Goukamma Natuurreservaat, De Hoop Natuurreservaat en Keurboomstrand langs die suidkus; Me Dougall's Baai en die Olifantsriviermond langs die weskus; Bazley en die rotsstrande van die St. Lucia Meer langs die ooskus van Suid Afrika; en langs die ooskus van Marion Eiland by Boulder Beach wat in die suidelike Indiese Oseaan geleë is, versamel. Lewende simbionte wat besig was om voort te plant is waargeneem deur ligmikroskopie en fotos is van die verskillende stadiums van tweedeling, telotrogvorming en konjugasie geneem. Mayer, Harris en Heidenhain Yster Hematoksilien is gebruik om die kerne te kleur. Die besonderhede van die infundibulum is bestudeer deur Bouin's gefikseerde smere met protargol te kleur. Kieue is ook met skandeerelektronmikroskopie bestudeer. Tweedeling is meestal in M. spadiceae waargeneem en is ook vroeër in M. spadiceae as in M. branchi en M. midae bevolkings waargeneem. Die vorming van telotroë is meestal in bevolkings van M. branchi en M. spadiceae waargeneem. Tydens hierdie studie was dit egter nie duidelik of tweedeling altyd voor telotrogvorming plaasvind en of tweedeling telotrogvorming volg nie. Konjugasie is meestal in bevolkings van M. branchi en M. midae waargeneem. Konjugasie is ook waargeneem in die Ellobiophrya spesie en hierdie is die eerste rekord van konjugasie in die genus Ellobiophrya (Chatton & Lwoff, 1923). Dit sal moontlik wees om hierdie prosesse in die toekoms in meer besonderhede te bestudeer as 'n geskikte kultuurmedium ontwikkel kan word.