北海道淡水産黄色鞭毛藻類の3種について

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(1)Title. 北海道淡水産黄色鞭毛藻類の3種について. Author(s). 芳賀, 卓. Citation. 北海道教育大学紀要. 第二部. B, 生物学,地学,農学編, 28(2): 53-59. Issue Date. 1978-02. URL. http://s-ir.sap.hokkyodai.ac.jp/dspace/handle/123456789/6354. Rights. Hokkaido University of Education.

(2) Journal of Hokkaido University of Education (Section H B) Vol. 28, No. 2 February 1978. WMH±Wm (^ 2 ^B ) It 28 ^ ^ 2 -f BgfD 53 ^ 2 ^. Notes on Three Fresh-Water Species of Chrysophyceae. from Hokkaido Masaru HAGA Biological Laboratory, Iwamizawa College, Hokkaido University of Education Iwamizawa 068. Î^7k;tXM?»X<^ 3Î(3î^. ^ M ^. u^Tir^'^ji^mf^f^. Abstract Three species of Chrysophyceae, Chrysamoeba radians KLEBS, Lepochromulina calyx SCHERFFEL, and a form of Salpingoeca frequentissima (ZACHARIAS) LEMMERMANN, all from moor waters from Hokkaido, were described for the first time in Japan. In this article, the transformation from amoeboid into monadoid in Chrysamoeba radians, the swarmer in Lepochromulina calyx,. and the process of budding to develop new individuals in a form of Salpingoeca frequentissima are also described.. Three species of Chrysophyceae, one of which is colorless and sometimes included in Craspedomonadaceae, are dealt with taxonomically in this study, since they have been never described in our country, and some aspects of their life-history seem to be incompletely reported. These unicellular algae were found in some of the samples collected from various moor waters. of Hokkaido, and were observed by means of the ordinary method of light-microscopy. The hanging drop method was also applied when the necessity arose.. Chrysamoeba radians KLEBS Cells free-living, solitary, with amoeboid and monadoid forms. In amoeboid form, cells naked protoplasts, approximately globose excluding rhizopods, about 12.5—15 p.m in diam. Protoplast provided with : 2 or sometimes 1, laminate to band-shaped, curved chromatophores without. pyrenoids; 2 contractile vacuoles; 1 flagellum; no stigma; usually 1 massive leucosin globule; and several, thick or thin, sometimes forked rhizopods which are radially arranged around protoplast-body in one plane.. In monadoid form, cells avoid to globose, 10—13 ^m in diam., each with single flagellum, and * Notes on fresh-water algae from Hokkaido. 4. (^l:i®it^^7J<j%^ / — h . 4. ). (53).

(3) M. HAGA. without rhizopods. Contractile vacuoles at the base of the flagellum, and chromatophores often parietal. (Figs. 1—3) Cysts (statospores) not found.. Loc. and Hab. A Phragmites communis-moor adjacent to Bibi River, Iburi Prov. (XI-11, 1967; XI-18, 1972. wat. temp. 9°C.). This material agrees with C. radians in Pascher (1913), Penard (1921), Huber-Pestalozzi (1941), MaTBHeHKo (1954, 1965), and Starmach (1968). MaTBHeHKO was of the opinion that the rhizopods of this species were thick, short, and their length scarcely exceeding the diameter of the cell-body. My observations revealed that in some specimens the rhizopods were much variable in. length and in shape. For example, well-developed amoeboid cells had comparatively long and delicate rhizopods (fig. la). In the amoeboid stage of the material, movement of rhizopods as well as streaming of internal protoplasm was slow, as already observed in this species (Penard, 1921). Each of two contractile vacuoles was located at the base of a comparatively prominent rhizopod or of bundles of smaller rhizopods, and a few persisting vacuoles were sometimes found in the peripheral groundplasm.. The leucosin globule was so conspicuous that it reminded me of the leucosin in Rhizochrysis nobilis SKUJA (Skuja, 1956). Innumerable granules, which were not light-refractive, were dispersed throughout the groundplasm. Though there was no direct evidence, they may be ingested solid food particles, since the ingestion of solid food by pseudopodia and food vacuoles were reported both in C. radians (Penard, 1921) and in C. gelatinosa BOURRELLY (Bourrelly, 1957). The transformation between the amoeboid and the monadoid occurred exclusively from the amoeboid to the monadoid in my material (fig.2), while the reversibility between the two forms was reported (Penard, 1921). As the amoeboid cell became rounded, very gradually the rhizopods shortened and disappeared, while the flagellum grew longer. The function of the contractile vacuoles and the movement of the protoplasm slowed down considerably and were barely per-. ceptible in the intermediate state between the two forms. The monadoid cell fitfully and slowly meandered even at the full development of the flagellum, which showed slow and wavy movement. The chromatophore in the monadoid which had become compacted was often parietal. The contractile vacuoles at the insertion of the flagellum appeared less active than those in the amoeboid. The leucosin globule usually placed at the poster! or (antiflagellar) end (figs. 3a—c).. Lepochromulina calyx SCHERFFEL Cells epiphytic, solitary, each composed of a uniflagellate protoplast housed in a stipitated lorica, which is always accompanied above with innumerable symbiotic microbial cells. Lorica truncated ovoid-ellipsoid, with an apical mouth, 7.5—11.0 /nm long, 5.5—6.6 ^m broad, usually colored light to deep yellowish brown. Stipe 3.3—6.5 (—8.5) //m long, 1.7—3.3 (—4.0) /am broad at the base of the lorica, usually narrower toward the lower end, colorless. Protoplast broad ellipsoid, 5.2—6.6 //m long, 3.3—3.7 /^m broad, with 1 parietal laminate chromatophore colored deep yellow. brown, 2 contractile vacuoles in the apical part, and 1 apically inserted flagellum, being about as. (54).

(4) Notes on Three Fresh-Water Species of Chrysophyceae from Hokkaido. long as the protoplast body. (Figs. 4,5) Loc. and Hab. On Oedogonium sp., in bog of Nikuruto, Abashiri Prov. (V-20., 1968); on Tribonema sp., in a dystrophic bog neighboring Lake Toro, Kushiro Prov. (VII-2., 1968. pH 6.2, wat. temp. 20°C); on fragment of a carapace of a Crustacea (?), in Bibi River of Yufutsu Moor,. Iburi Prov. (VII-28., 1972. pH 6.2, wat. temp. 18°C); On Hapalosiphon fontinalis (AG.) BORNET, in a shallow pool of Takushin Sphagnum-Moor, Shinshinotsu V., Ishikari Prov. (VI-25., 1974. pH 5.2, wat. temp. 21.5°C). The material under study was identified as L. calyx according to Pascher (1913), Geitler (1949), Bourrelly (1957), MaTBMeHKo (1954, 1965) and Starmach (1968). In all the vegetative cells so far observed in this study, there was no connecting strand. between the base of the protoplast and the bottom of the lorica, but some of the protoplasts showed a slow but strictly vertical movement, sometimes rotating, as if controlled by repeated extension and contraction of the connecting strand.. Swarmers were found but in only one sample from Bibi River in July. They were ellipsoidal, smaller than protoplasts of vegetative cells (4.5—4.8 /^m x 3.0—3.7 ^/m), and each provided with 1 parietal laminate chromatophore, 2 (?) contractile vacuoles contracting in a long interval, and a flagellum which was about twice as long as the body or less, showing a very slow movement.. Numerous tiny spheres around the swarmer looked undoubtedly identical to those covering the vegetative cell, which were shown to be a symbiotic microbe (Geitler, 1949) (fig. 5b). Together with swarmers, few vegetative cells having enlarged protoplasts with double chromatophores (fig. 5a), and those having dividing or divided protoplasts, were found. Therefore it seems very likely that soon after division of the cell at least one of the daughter protoplasts is liberated to be a swarmer. At present it is not known whether the swarmer is zoosporic or gametic.. Salpingoeca frequentissima (ZACHARIAS) LEMMERMANN Cells epiphytic, solitary, each composed of a stipitated lorica and an enclosed collared protoplast. Lorica thin, colorless, short vase-shaped with a wide apical mouth, posteriorly drawn out into a short, hollowed stipe, 7.5—10.5 p.m long without stipe, 4.2—6.0 fim broad. Protoplast-body colorless, usually occupying lorica, up to the mouth except the bottom, and containing 1 central. nucleus, 2 posterior contractile vacuoles; provided on the apex with single flagellum which is about 7—15 /^m long. Collar funnel-shaped, very delicate, usually 5.5—6.5 /urn long, projected out. anteriorly through the mouth encircling the flagellum. Asexual reproduction (budding) by uniflagellate rhizopodial protoplasts brought about by bipartite longitudinal division of mother-cells. (Figs. 6,7) Loc. and Hab. On Microspora sp. in a drain of Sphagnum-moor at Higashi Nopporo, Ishikari Prov. (X-3L, 1968. wat. temp. 7.5°C) The lorica of S. frequentissima was described as 3.7—4.5 //m broad at the middle, 4.5—6 p.m. broad at the mouth by Lemmermann (1914), Huber-Pestalozzi (1941), and Starmach (1968), but the lorica-body of the present material was about as broad as the mouth. The delicate rhizoids from the stipe in order to anchor the body to substrata which were also described by these investigators. (55).

(5) M. HAGA were not confirmed in my material. These differences of my material from those investigators however, are not considered so important as to call for a description of another new taxon at present. Further studies are required.. Process of asexual reproduction was observed during midnight hours in the material in a sampling bottle which was collected and brought into the laboratory the day before. The budding, which generally occurs in Protozoa as a mode of reproduction (e.g. in Grell, 1973), may be an. applicable term to the case in this study (figs. 7a—g). Cells having unusually expanded protoplast-bodies which were sometimes provided with 2 nuclei were usually inactive in metabolic and flagellar movement, while in usual cells the movement was so active that no organelles could be distinguished, and numerous granules, some of. which looked somewhat glistening, streamed rapidly in the protoplast. Protoplasts of those expanded and quiescent cells having undergone karyokinesis appeared ready to divide. The most outstanding indication of the division was given by the rising of the protoplast-body toward the mouth of the lorica: at first slowly oscillating, it began to move up and down repeatedly, then gradually rose; at the same time metabolic and flagellar movement intensified. Within 20 minutes the protoplast-body reached the mouth of the lorica and stayed there, extruding from half to two thirds out of the lorica (fig. 7a). Frequently the collar was retracted to about one third or less of the usual length. Then another short flagellum became apparent beside the first flagellum. After staying there for a few minutes, the protoplast again moved further upward, and leaned out the. edge of the lorica. Then protoplast-division followed suddenly. It began at lower surface of the protoplast where the edge of the lorica touched, and proceeded toward the flagellated apex, as if cut off by the edge. Within 3 minutes 2 daughter protoplasts of approximately equal size were produced (fig. 7b). Thus the division was longitudinal, as generally accepted in Craspedomonadaceae (Lemmer-. mann, 1917; Fritsch, 1948), but in this material the protoplast was split from the posterior to the anterior end. A pair of protoplasts being in contact with each other side by side and having a common collar was figured by Stein in S. oblonga STEIN (in Btitschli, 1885). The two protoplasts were thought to be either a pair of daughter protoplasts immedately after longitudinal division, or a pair in conjugation where the collars had fused (Btitschli, 1885). My observation in the present study supports the former view, and suggests that Stein's drawing showed a stage at which. division of a protoplast-body, that had occurred from the posterior to the anterior end, just finished, and the collar was ready to separate subsequently. A stage similar to the one Stein drew was also found in my material. The mode of division is not considered, therefore, to be abnormal, but possibly common.. One of the daughter protoplasts which was hanging at the edge of the lorica was spheric, without the collar, but provided with a supposed collar- or lorica-primordium-like very small. outgrowth encircling the flagellum, and also with numerous fine rhizopods radiating from the surface particularly from the upper hemisphere (fig. 7b). On the other hand the other daughter protoplast withdrew quickly inside the maternal lorica, and very soon recovered its collar and activity.. As the rhizopods further developed, the protoplastbody detached from the mouth of the. (56).

(6) Notes on Three Fresh-Water Species of Chrysophyceae from Hokkaido. maternal lorica, and slowly descended along the outer surface of the lorica-wall by means of. rhizopodial movement, and this descent looked like "walking" by the rhizopods (fig. 7c). Moving down along the wall of lorica, the protoplast stopped at a point on the substratum near the mother-cell, and stood still, its flagellated end upwright, changing to an avoid shape with a pointed apex, from which the flagellum grew (fig. 7d). The flagellar movement almost ceased for several minutes during this transfer of the protoplast by rhizopodial movement. Then the rhizopods concentrated gradually to the basal end of the cell and became a fine, thread-like stipe. At the same time the cell became vase-shaped, with an extended collar, but the. lorica was not yet visible. This state of the cell looked very similar to cells of genus Monosiga, hence it might be called the Monosiga -stage (fig. 7e.f). After the stipe formed, streaming of the protoplasm, activity of the contractile vacuoles and of the flagellum became vigorous; in particular the flagellar movement appeared rather violent. Subsequently, for an hour or so, the collar gradually extended, and a more or less solid wall was secreted to form the lorica. Though not yet grown enough, the cell was characteristic of. Salpingoeca (fig. 7g). Describing asexual reproductive processes in 2 species of Salpingoeca, Penard (1921) reported that one of the daugher protoplasts after transverse division became a swarmer, or settled near. the mother cell and metamorphosed into a new individual without swimming. The daughter protoplast as described soon after division by Penard is very similar in structure to that observed in this study, but lacks rhizopods. In Penard's description the daughter protoplast was shown to "slip" or "glide" down along the lorica of the mother cell, and to stop, to stand upwright, and then to secrete the stipe and the lorica. In the present material, as described above, the rhizopodial movement was the only means for the transfer of the daughter protoplast. However, it seems. likely that the daughter protoplast is controlled by environmental conditions to adopt either a flagellar, a rhizopodial, or a gliding movement, because the daughter protoplast is considered essentially the same as the protoplast of the usual vegetative cell, which was reported in some. species to have rhizopods or lobopods as partial or entire modification of the collar (Btitschli, 1885; Penard, 1921; Skuja, 1948). I wish to thank Prof. H. Nishida, Hokkaido University of Education, and Prof. M. Kurogi, Hokkaido University, for their continued interest and valuable advice. Thanks are also due to Drs. Y. Nishihama, Hokkaido Mariculture Research Institute, M. Watanabe, National Science Museum,. and T. loriya, Tokyo University of Fisheries, for their friendly cooperation in collecting materials and helpful suggestions.. References Bourrelly, P., 1957. Recherches sur les Chrysophycees. Rev. Algol. Mem. Hors.-Serie 1 : 1—412. Butschli, 0., 1885. Mastigophora. In Bronn, H. G. (ed.) Klassen und Ordnungen des Thier-Reichs. I. Abt.2. C.F. Winter. Leipzig, Heidelberg. p. 904. Taf. 49. Fritsch, F. E., 1948. The Structure and Reproduction of the Algae. I. Cambridge Univ. Cambridge. p. 746. Geitler, L., 1949. Symbiosen zwischen Chrysomonaden und knospenden Bakterien-artigen Organismen sowie. (57).

(7) M. HAGA. Figs. 1-3. Chrysamoeba radians KLEBsQa, Well-developed amoeboid cell; Ib, Typical amoeboid; 2,. Amoeboid cell transforming into monadoid; 3a-c, Monadoid cells) Figs. 4, 5. Lepochromulinacalyx SCHERFFEL (4, Vegetative cells; 5a, Cell with 2 chromatophores; 5b. Swarmer; 5c. Cell with 2 protoplasts supposedly after division) Figs. 6, 7. Salpingoeca frequentissima (ZACH.) LEMM. (6, Vegetative cells; 7a-g, Successive stages of asexual reproduction, so-called budding). Beobachtungen uber Organisationseigentumlichkeiten der Chrysomonaden. Oester. Bot. Zeitschr. 95 : 300-. 324. Grell. K. G., 1973. Protozoology. Springer Verlag. Berlin, Heidelberg. pp. 145-152. Huber-Pestalozzi, G., 1941. Das Phytoplankton des Susswassers. In Thienemann, A. (ed.) Die Binnengewasser. 16.. Teil 2 (1). Schweizerbart. Stuttgart. pp. 303.. Lemmermann, E., 1914. Flagellatae 1. In Pascher, A. (ed.) Die Susswasser-Flora Deutschlands, Osterreichs, und der Schweiz. 1. G. Fischer. Jena. pp. 77-83.. (58).

(8) Notes on Three Fresh-Water Species of Chrysophyceae from Hokkaido MaTBneHKo, A.M., 1954. SojioTHCTbie BoAOpocjiH. OnpeAejiHT. npecHOBOA. BoAOpocji. CCCP. 3. CoBeTCKan HayKa. MocKBa. pp. 188.. MaTBHeHKO, A.M., 1965. SojioracTbie BOAOPOCTH — Chrysophyta. BHBH. npecHOBOA. BoAOpocT. VKpaHH. PCP. Ill (1). HayKoea AyMKa. KHCB. pp. 365. Pascher, A., 1913. Chrysomonadinae. In Pascher, A. (ed.) Die Susswasser-Flora Deutschlands, Osterreichs, und der Schweiz. 2. Flagellatae 2. G. Fischer. Jena. pp. 5—95. Penard, E., 1921. Studies on some flagellata. Proc. Acad. Nat. Sci. Philadelphia 73 : 105-168. Skuja, H., 1948. Taxonomie des Phytoplanktons einiger Seen in Uppland, Schweden. Symb. Bot. Upsal. 9 (3) : 301. Taf. 34, fig. 12-15. Skuja, H., 1956. Taxonomische und Biologische Studien uber das Phytoplankton Schwedischer Binnengewasser. Nov. Act. Reg. Soc. Sci. Upsal. IV. 16 (3) : 292. Taf. 50, fig. 33; Taf. 51, figs. 1-3. Starmach, K., 1968. Chrysophyceae—Zlotowiciowce oraz Wiciowce Bezbarwne—Zooflagellata Wolnozyjace. Flora Slodkowodna Polski 5. Chrysophyta I. Panstw. Wydawnist. Nauk. Warszawa. pp. 598.. (59).

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