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.