A Redescription of Remanella Multinucleata (Kahl, 1933) Nov
Total Page:16
File Type:pdf, Size:1020Kb
Europ. J. Protistol. 32,234-250 (1996) European Journal of May 31, 1996 PROTISTOLOGY A Redescription of Remanella multinucleata (Kahl, 1933) nov. gen., nov. comb. (Ciliophora, Karyorelictea), Emphasizing the Infraciliature and Extrusomes Wilhelm Foissner Universitat Salzburg, Institut fOrZoologie, Salzburg, Austria SUMMARY The morphology, infraciliature, and extrusomes of Remanella multinucleata (Kahl, 1933) nov. comb. were studied in live cells, in protargol impregnated specimens, and with the scanning electron microscope. The entire somatic and oral infraciliature consists of diki netids which have both basal bodies ciliated or only the anterior or posterior ones, de pending on the region of the cell. The right side is densely ciliated. Its most remarkable specialization is a kinety which extends on the dorsolateral margin from mid-body to the tail, where the kinetids become condensed and associated with conspic uous fibres originating from the ciliated anterior basal bodies. The left side seemingly has two ciliary rows extending along the cell margins. However, detailed analysis showed that these rows are very likely a single kinety curving around the cell. The oral infraciliature of Remanella is very similar to that of Loxodes spp., i.e. consists of four highly specialized and specifically arranged kineties, whose structure is described in detail. Previous inves tigations could not determine whether or how the nematocyst-like extrusomes of Rema nella are extruded. The present study shows that they are discharged, thereby assuming a unique, drumstick-like shape because the roundish extrusome capsule remains attached to the despiralized filament. The data emphasize the close relationship between Remanella and Loxodes, earlier proposed by Kahl, and suggest that they emerged from a common ancestor which looked similar to a present day Loxodes. Remanella Kahl, 1933 is a nomen nudum because Kahl, when founding the genus with five new species and one new variety, failed to designate any as type. I thus reinstall Remanella nov. gen. for the species assigned to Kahl's invalid taxon and fix R. multinucleata as type species. Correct names, dates, and authorships are provided for all species described. Introduction ures are highly schematic and hardly show the details required for a proper comparison with Loxodes and Species of the karyorelictid ciliate genus Remanella related genera [1, 3, 10-12]. Using a new fixative, are common in marine interstitial and intertidal en invented by Jean Dragesco, and Wilbert's protargol vironments [10, 17, 26, 27]. Ultrastructural studies technique, I got some excellent preparations showing [37,40] on the somatic cortical organization confirmed many previously unrecognized details, which are re the close relationship with Loxodes, the sole freshwater ported in this study, together with some speculations karyorelictean genus, proposed by Kahl [26], the foun on evolution in loxodid ciliates. Furthermore, a de der of the genus. However, a detailed study of the so tailed redescription of R. multinucleata is provided be matic and oral ciliary pattern of Remanella was never cause previous studies do not meet the present standard performed, possibly because it was difficult to reveal of ciliate alpha-taxonomy. Last not least, extensive no with the preparation methods available. Published fig- menclatural changes are required because Kahl, when 0932-4739-96-0032-0234$3.50-0 © 1996 by Gustav Fischer Verlag, Stuttgart Infraciliature of Remanella . 235 founding the genus with five new species and a new Remanella as new genus to avoid an inflation of names. variety, unfortunately failed to designate an y as type . Furthermore, I fix R. multinucleata (Kahl, 1933) nov. Thus, the genus is illegitimate according to the Interna comb. as type species of the new genus, for which an tional Code of Zoological Nomenclatu re [25]. improved diagnosis is provided in the discussion. AU Remanella specie s described need to be combined with the new genus. Note th at Carey [5], without giv Material and Methods, Type specimens, ing any rea son, quotes Dragesco [10] as combining Terminology author of Kahl's [26] and Dragesco's [8, 9] species although he accepts Kahl [26] as founder of the genus Remanella multinucleata occurred in considera ble number and Dragesco [10] did not recognize Kahl's [26] mis in the mesopsammon of the French Atla ntic coast at Roscoff. take. Carey 's [5] species citation is difficult to und er Samples were collected and treated exactly as described by sta nd; possibly, he simply did not know that Faure-Fremiet [14], i.e. the specimens were detached from international rules exist. There are also several other the sand grains by adding about 5 ml of a 12% MgCl solu 2 nomenclatural mistakes. Thus, I decided to revise the tion to about 20 ml sand and sea water. Th e mixture was then gently rotated in a petri dish so that the sand collected in the nomenclature of the whole genus for the benefit of sta center and the ciliates could be picked up individually with a bility, the present paper, and future workers. capillar y pipette from the clear superna tant . The genus name is derived from Adolf Remane Cells were studied in vivo using a high-power oil immer (1898-1976), famous German zoologist and one of sion objective and differential inte rference contrast [19J. the discoverers of the marine interstitial fauna. Rema The infrac iliarure was revealed by protargol impregnation nella has feminine gender acco rding to article 30b of [19; protoco l 2, Wilbert's meth od], using a special fixative in the ICZN [25]. vented by Jean Dragesco (pers. com m.): 5 ml gluta raldehyde 1. Remanella brunnea (Kahl, 1933) nov. comb. (pub (25 %),5 ml saturated, aqueous mercuric chloride, 3 ml aqu eous osmium tetroxide (2%), and 1 ml glacial acetic acid are lished by Kahl [26 , 27] without figure; well rede mixed just before use. Specimens are fixed for 15-30 min. scribed in [12) ); and washed th ree times in dist illed water. Preparation for 2. Remanella caudata (Dragesco, 1954b) nov. comb. scanning electron microscopy (SEM ) was performed as de (misdated by Carey [5] as 1953 although the jour scribed by Foissner [19], using the fixative mentioned above. nal clearl y states "paru en december 1954"); Counts and measurements on silvered specimens were per 3. Remanella dragescoi (Agamaliev, 1966) nov. formed at a magnificat ion of X 1000. In vivo measurement s comb.; were con ducted at a magn ification of X 40-1000. Altho ugh 4. Remanella faurei (Dragesco, 1954a) no v. comb.; these provide only rough estima tes, it is worth giving such 5. Remanella gigas (Dragesco, 1954a) nov. comb.; dat a as specimens usually shrink in preparat ions or co ntract during fixat ion. Stand ard deviat ion and coeffic ient of varia 6. Remanella granulosa (Kahl , 1933) nov. comb.; tion wer e calculated accordin g to sta tistics textboo ks. Draw 7. Remanella levii (Dragesco, 1960) nov. comb.; ings of live specimens are based on free-ha nd sketches and 8. Remanella margaritifera (Kahl, 1933) no v. comb.; micrograph s, those of impregnated cells were mad e with a 9. Remanella microstoma (Dragesco, 1954b) nov. camera lucida. comb. (misdated by Ca rey [5]; see above); No type slides of R. multinucleata are mentioned in the 10. Remanella minuta (Dragesco, 1954a) nov. comb.; literature. Thus, I have deposited two neotype slides with spe 11. Remanella multicorpusculata (Vacelet, 1961) nov. cimens prepared as described in the Oberosterreichische comb.; Landesmuseum in Linz (LI) , Austria. Relevant specimens 12. Remanella multinucleata (Kahl, 1933), type of arc marked by a black ink circle on the cover glass. genus (see above); Terminology is according to Co rliss [6] and Foissner & Rieder [21J, with slight modifications, and strictly descr ipt ive 13. Remanella obtusa (Faure-Fremiet, 1951) nov. because ontogenetic data are incomplete and conflicting [28, comb. (very likel y doe s not belong to this genus; 30, 42J. see discussion); All figures are oriented, if not sta ted ot herwise, with the 14. Remanella rugosa (Kahl, 193 3) nov. comb.; an ter ior end of the organism directed to to p of page. 15. Remanella rugosa var. unicorpusculata (Kahl , 1933) nov. comb. (established as "species nova " by Dragesco [12] due to misinterpretation of arti cle 45g of the ICZN); Results 16. Remanella swedmarki (Drages co, 1954a) no v. comb.; Remanella Kahl, 1933 is Invalid under Article 13b of the ICZN [25] 17. Remanella trichocysta (Dragesco, 1954a) no v. comb. (nom. ern.; the original spelling "trichocys Kahl [26] founded Remanella with five new species tus" cannot be a Greek or latinized noun in appo and one new variety, none of wh ich, unfortunately, he sition, as Dragesco possibl y had in mind, because designated as type . The genus is thus invalid according the noun is "trichocystis" . Thus, the species name to the ICZN. This wa s overlooked not only by Kahl has to be treated as latinized adjective and coordi [27] but also by the first reviser of the genus [10] nat ed with the gender of genus; article 31 of the and later monographers [5, 6]. I thus declare Rema ICZN); nella Kahl, 1933 to be a nomen nudum, but reinstall 18. Remanella unirugosa (Hartwig, 1973) nov. comb. 236 . W. Foissner - 8 5 6 :: , :·::·Z :-,\; LC- :·:·:.\. "': \ ".:~' " :\ \ 2 Figs. 1-10. Remanella multinucleata from life (Figs. 1-6,9,10) and after protargol (Fig. 7) and wet silver nitrate impreg nation (Fig. 8). - Fig. 1. Right lateral view of typical specimen. - Figs. 2, 3. Spiralized and undulating specimens. - Figs. 4-7. Internal structures. - Fig. 8. Silverline system at ventrolateral margin. - Figs. 9, 10. Surface views of left and right side. B = buccal overture, DM = developing Muller vesicle, E = extrusomes, FV = food vacuole, G = cortical pigment granules, LC = left lateral ciliary row, M = Muller vesicle, MA = macronuclei, MI = micronuclei, N = nuclear chain, P = pharyngeal tube, S = spicules.