植物研究雑誌 1. 1. Jpn. Bo t. 70: 70: 77-84 (1 995)

Laboratory Laboratory Culture and Life History of Trichosolen (=) myura (J. Agardh) Taylor from It aly

Mitsuo CHIHARA a and Takaaki KOBARA b

aTh e Japanese Red Cross College of Nursing ，4・ 1-3 Hiroo ，Shibuya-ku ，Tokyo ， 150 JAPAN; bSenshu bSenshu University ， 2-1-1 Higashi-mita ，Tama-ku ，Kawasaki ，Kanagawa ，214 JAPAN

(Received (Received on May 14 ， 1994)

Themo 中hology and life history of Trichosolen myura (J. Agardh) Taylor (Syn. Pseudobryopsis myura Berthold) Berthold) are redescribed ，based on material from It aly. Individual thalli are monoecious ，with male and female gametes gametes in separate gametangia. Zygotes produced from gametic fusion develop into prostrate filaments with branches branches and irregularly spaced constrictions. These filaments produce new Trichosolen thalli directly. The life

history history ofthe alga 合om Italy is identical with that from Syria (Mayhoub 1974). Herbarium specimens of T. myura collected collected in Japan by Yendo (1 915) have been examined and are reassigned to .

Introduction Materials and Methods Trichosolen Trichosolen myura (J. Agardh) Taylor was origi- The specimens used in the present study were nally nally described by J. Ag 征 dh (1842) under the name of collected at Ischia Island near Naples (July 2， 1987) Bryopsis Bryopsis myura ，and was based on specimens col- and at Maria la Scola ，Sicily Island (J uly 8， 1987) in lected lected in Italy. The type locality was not specified and Italy by one of us ，M. C. They were growing on rocks only only a brief morphological description was given. The several meters below low tide. The specimens for species species was later transferred to Pseudobryopsis morphological observation were preserved in forma- Berthold in Oltmanns (1 904) ，but Trichosolen lin seawater ， while living material for laboratory Montagne (1861) is now recognized as having prior- culture was put into plastic bottles with natural seawater ity ity (Taylor 1962). Feldmann (1937 ， 1969) provided and brought back to the laboratory. The unialgal details details of the morphology and reproduction of T. culture was started from excised apical portions of myura on the basis of the collections at Banyuls on the main axes and ramuli. All cultures were grown in ES Mediterranean Mediterranean coast of France. Mayhoub (1974) has medium (Proyasoli 1966) at 23 0 C and under a light also also studied the life history of T. myura but on speci- regi 11l e of 18h: 611 (l igh t: dark) ， with light intensity of mens collected in Syria. On the basis of these publica- 3，000 -4， 000 lux provided by cool white fluorescent tions tions it appe 訂 s that there is a difference in size of lamps. Under these conditions ， the thalli grew well gametangia between the specimens from France and and produced gametes. The filamentous germlings

Syria. Syria. The former has relatively small gametangia. In resultingfrom thezygotes ，九 rere cultured at five differ- this this paper we describe the morphology and life ent temperatures: 15 0 C ，18 0 C ，21 oC ，24 0 C and 2TC. history history of T. myura collected in Italy. Observations of nuclei were made using the fluoro-

-:-77- 78 植物研究雑誌第70 巻第2 号 平成 7 年 4 月 chrome DAPI (Coleman 1979). In addition ，speci- the papillum ruptured and gametes were liberated mens in Yendo's collection at the University Mu- through the aperture. Male gametes were liberated as seum ，University of Tokyo (TI) (now deposited in a jet cloud ， as reported in hainanensis Trichosolen the the Hokkaido University Herbarium) were examined. (Kobara and Chihara 1978a). Female gametes were also also liberated rapidly (Fig. 7). When female gametes Observations Observations matured in the gametangia of healthy thalli ， they Morphology swam about immediately after liberation ， without The specimens collected at Ischia Island and Sicily outside staying the gametangium. Sometimes ， the Island Island are similar to each other in their gross mo 叩hol- liberated female gametes stayed as a mass at the tip of ogy. ogy. Thalli are clustered with the numerous main axes gametangium for one or two minutes before swim- originating originating from a common rhizoidal base (Fig. 1). ming away ， as reported by Feldmann (1969) in T. Main axes are up to 120 mm long and 40 0- 1，000μm myura. Male and female gametes possessed two equal wide. wide. Relatively short main axes 紅 e always simple ， anterior flagella. Female gametes were 7-10μmlong but but longer axes are generally branched sub- and 4-5μm wide ， and generally possessed several dichotomously dichotomously or laterally. Axes and branches have green chloroplasts and a red eyespot (Fig. 8). 乱1ale numerous ramuli except on the lower par t. Ramuli are gametes were 4-5μm long and about 2μmwide ， with 2-3 mm long ，2 0-4 0μm wide ，soft ，and arranged one pale green chloroplast and no eye spot (Fig. 9). around around the branches. Gametangia 訂 e ovoid in shape ， When male and female gametes met ，conjugation 100-180μm long and 65-110μm wide ，and each has took place immediately ，resulting in the formation of a papillum at the tip. They are produced adaxially near zygotes (Fig. 10). The zygotes remained motile for the the base of ramuli ，usually singly ， but there 訂 esome- about one hour before attaching to the bottom of the times times two or three per ramulus. Chloroplasts are very culture vessel (Fig. 11). Within three days ， zygotes small ，2-4 μm long and about 2μm wide ， with no increased in volume ， with the formation of a vacuole pyrenoid. pyrenoid. in the cells. After seven days ， they began to germinate (Fig. (Fig. 12). One week later ， the microscopic filament Life Life history produced one to severallateral branches and irregular In In culture ，apical portions grew into erect main constrictions (Fig. 13). After a further six weeks ， the axes axes with ramuli and associated rhizoidal filaments. much branched filamentous germlings were to 5 mm Later ，many erect axes developed from rhizoidal long and 25-50μm in diameter (Figs. 14 ，15). They filaments filaments and those produced ramuli in the upper had a single nucleus ， as already reported by Neumann parts. parts. After about a month ， the cultured thalli had a (1 970) (Fig. 16). The germlings attached on oyster clustered clustered appearance (Fig. 2). Many gametangia were shells and corals did not pene 廿ate the substrates. produced produced adaxially ， near the base of the ramuli (Fig. In orderto examine the possibility of parthenogen- 3). 3). The alga was monoecious. Male and female esis ，male and female gametangia were excised from gametangia gametangia differ from each other in color: male parent thalli and isolated. Unfused male and female gametangia gametangia were light yellowish-green ， while fe- gametes did not develop. males males were dark brownish-green (Fig. 4). Generally After three months growth attemperatures of 21 oc

0 gametangia gametangia of the same sex were produced on single and 24 C ， the prostrate filaments produced erect fila 四 ramuli ramuli (Fig. 5) but rarely the two sexes occurred ments directly (Figs. 17 ，18). These were produced together together (Fig. 6). At the beginning of a light period ， mostly from the terminal ends and were thicker than April April 1995 Jou ll1 al of Japanese Botany Yo l. 70 No. 2 79

Figs. 且-11 ・ 1 n cnosolen myura. 1: Specimen s collected atMaria la Scola ，Sicily Island (July 8， 1987).2: Thallus in culture developed from an apical piece ofaxis or branches ，after 4 weeks. 3: Portion of the thallus ，showing gametangia produced adaxially near the the base of ramuli. 4: Male (I ight yellowish-green) and female gametangia (dark brownish-green) produced on a thallus. 5: two male gametangia (upper) and two female gametangia (1 ower) produced on separate ramuli. 6: Male gametangium (upper) and female female gametangium (I ower) produced on a single ramulus. 7: Female gametangium ，liberating female gametes. 8: Female gametes. gametes. 9: Male gametes. 10: Zygotes. 1 1: Zygotes attached to the substratum. 80 植物研究雑誌第70 巻第2 号 平成 7 年 4 月 • ~

吋乙~ヘ，---←『田町 一

Figs. Figs. 12-21. Trichoso/en myura. 12: Germinating zygotes. 13: Young germling developed from the zygote ， with branches. 14: Two month old germlings. 15: Two month old germling with several branches and irregular constrictions. 16: Filamentous germling containing containing single nucleus. 17 - 18: Erect filaments developed directly from a filamentous germling . 19: Erect filament containing numerous small nuclei. 20: Erect filament with ramuli. 21 : Typical Trichosolen thallus developed from the filamentous germling. Apri11995 Apri11995 Joumal of Japanese Botany Vo l. 70 No. 2 81 the the prostrate filaments. One to twelve erect filaments filaments. At the higher temperature of 2TC ， only a were produced from each germling. Some of the few erect filaments were produced camong about a protoplasm protoplasm of the prostrate filament appeared to move hundred of filamentous germlings ， but the production into into the erect filaments and ， as a result ，a part of the of gametangia was not depressed. prostrate prostrate filament became pale green or transparen t. At this stage ， both the erect thalli and prostrate fila- Examination of Japanese specimens of Tricho- ment contained numerous small nuclei (Fig. 19). The solen myurafrom the Herbarium ofYendo subsequent subsequent formation of a stephanokont zoospore as In the University Museum ，University of Tokyo reported reported in T. hain α nensis (Kobara and Chihara 1978b; (TI) ， in which Yendo's collection was deposited ，we

Okuda et al. 1979) was not observed. The erect found two herbarium 戸pecimens named as Bryopsis filaments filaments grew rapidly and produced many ramuli myura ，a basionym of Trichosolen myura. One of

訂 ound the upper part of the axes (Fig. 20) ，and these is shown in Fig. 22 with its label in Fig. 23. rhizoidal rhizoidal filaments at the base. Later ， these rhizoidal Another specimen with similar morphology had the filaments filaments produced several more axes. erect Tricho- name Bryopsis myura written in pencil but it was solen solen thalli as found in nature developed within four unlabelled. The gross morphology of the specimens in months of fertilization (Fig. 21) ，and these produced Yendo' s herbarium is clearly different from that of gametangm. Trichosolen myura collected in It aly (Figs. 24， 25). In In contrast three month old filamentous germ- Yendo's specimens had relatively thick ramuli (Fig. lings lings cultured at 1SOC and 18 0 C did not produce erect 24) ，and did not exhibit the specialized gametangia ，

Figs.22-24. Figs.22-24. Yendo's herbarium specimen labelledBryopsis myura 合omBintare Island. 25. Portion of an herbarium specimen of Trichosolen Trichosolen myura (Sicily Island) ，at the same magnification fig. as 24. 82 82 植物研究雑誌第 70 巻第2 号 平成 7 年 4 月

which are characteristic of Trichosolen. In contrast 1969 ，1975). Huizing andRietema(1975 ，1979)stud-

the the relatively thin of ramuli Trichosolen are 訂 ranged ied the cell wall constituents of some siphonous green densely ， and the specialized gametangia can be seen algae and concluded that Trichosolen and Bryopsis

using using a dissecting microscope. 紅 e not closely related. They recorded the cell wall of both both the macrothallus and the filamentous microthallus Discussion Discussion of T. myura as consisting mainly of mannan. In Themo 中hological features ofthe specimens col- B ryopsis the cell wall of macrothalli was mainl y xy lan lected lected in Italy agree well with those of Trichosolen whereas in the filamentous microthalli it was mainly myura from France (Feldmann 1937 ，1969) ， except mannan (see also Chihara et al. 1982). Our observa-

for for the size of gametangia. In the specimen from tions 訂 e at variance with this conclusion. We have Banylus Banylus in France ， they were reported to be in the examined the constituents of T. hainanensis (Chihara range range 110-120μm long and 70-90μm wide et al. 1982) and T. myura (Chihara et al. 1988) and in (Feldmann (Feldmann 1937). In the specimen from Syria ， they both cases the macrothallus walls were mainly xylan

were recorded as 120 ー220μm long and 70 ー100μm while those of filamentous microthalli were mainly wide (Mayhoub In 1974). our specimens from It aly ， mannan. Our results on the cell wall constituents and gametangia gametangia in field collections were 10 0- 180μm the life histories of Trichosolen indicate that long long and 65-100μm wide ， and in culture 90-200μm Trichosolen andBryopsis are closely related. The cell long long and 65-90μm wide. These values overlap with wall staining reaction with chlor-zinc- iodine was nega- those those of both French and Syrian specimens. tive in Trichosolen macrothalli ， whereas it is positive The life history ofTrichosolen myura from Italy is in Bryopsis ， as Huizing and Rietema (1975) have fundamentally fundamentally identical with that reported in Syrian already reported. We have no explanation for this material material (Mayhoub 1974). Mayhoub (1 974) pointed discrepancy but note that the cell wall of Caulerpa

out out the mo 中hological and cytological similarities does not stain with chlor-zinc-iodine ， even though the between between filamentous germlings of T. myur αand main constituent is xy lan (Iriki et al. 1960; Mi wa et al. Ostreobium Ostreobium queketii Bomet et Fl ahaul t. Ostreobium 1961). is is a siphonous green alga which penetrates the cal- Trichosolen myura was recorded from Japan by cium carbonate substrates. Our experiments show Yendo (1 915) under the name of Bryopsis myura J. that that the filamentous ge ロnlings of T. myura do not Agardh ， but he did not include any morphological penetrate penetrate oyster shells and corals: neither do the description. The locality given was “Hyuga" germlings germlings of T. hainanensis (Kobara and Chihara (Miyazaki-ken). Later ，Okamura (1 936) recorded T. 1978a). 1978a). These observations support the Kommann myura in his “Nippon Kaiso-shi" under the name of

and and Sahling' s (1981) view that the two algae are Pseudobryopsis myura (1. Ag 訂 dh) Berthold ， and different different taxa. Kommann and Sahling (1981) showed gave it the J apanese name “ Nise-hanemo". However ， that that o. quekettii produces quadriflagellate zoospores this record was only a citation of Yendo' s record. As in in the sporangia. as far we know ，there is no other published record of There There are similarities between the life histories of T. myura from Japan. In the examination of Yendo' s Trichosolen Trichosolen andBryopsis (Kobaraand Chihara 1978b). herbarium ，two sheets of T. myura were found. They The life history ofTrichosolen myura is similar to that were collected at Bintare Island (the local inhabitants ofthe ofthe “ Zeeland type" of ， whereas call this Bindare Island) ，Kusima-shi ，Miyazaki-ken. that that of T. hain α nensis is “ Roscoff type" (Rietema Probably ，T. myura from J apan was described on the Apri11995 Apri11995 Joumal of Japanese Botany Vo l. 70 No. 2 83 basis basis of these specimens because the island is located ents of several siphonous green algae in relation to morphol- ogy ogy and . Br. Phyco l. J. 14: 25-32. in in Hyuga (Miyazaki Prefecture). The thick ramuli Ir iki Y. ， Suzuki T. ， Nisizawa K. and Miwa T. 1960. Xylan of and absence of specialized gametangia of the speci- siphonous green a1gae. Nature 187: 82-83. Kobara Kobara T. and Chihara M. 1978a. On the taxonomy and repro- mens indicate that they belong to the genus Bryopsis. duction duction of the siphonous green alga Pseudobryopsis We wish to express our gratitude to D r. Robert J. hainanensis Tseng. J. Jpn. Bo t. 53: 341-352. 一一一一，一一一一 1978b. On the life history of Pseudo- King ，University ofNew South Wales ，Australia ， for bryopsis bryopsis hain α nensis (Chlorophyceae). J. Jpn. Bot. 53: his his reading of the manuscrip t. Thanks are also due to 353-360. Mayhoub H. 1974. Reproduction sexuee et cycle du the the curator of the herbarium of TI ，who enabled us to developpement developpement de Pseudobryopsis myura (Ag.) Berthold examine the specimens of the Yendo' SB1YOpsis myura. (Chlorophyee ，Codiale). C. R. Acad. Sc. Paris 278: 867- 870. 870. One of us ，M. C. ， is grateful to D r. Donato Marino ， Miwa T. ， Ir iki Y. and Suzuki T. 196 1. Mannan and xylan as Stazione Zoologica di Napoli ，Ms. Maria Cristina essential cell wall constituents of some siphonous green algae. algae. Col l. 1ntem. C. N. R. S. 103: 135-144. Buia ，Laboratorio di Ecologia del Benthos ，Stazione Montage C. 186 1. Neuvi とme centurie de plantes cellulaires Zoologica di Napoli ，Ischia ，and Professor Giacomo nouvelles taut indig とnes qu' exotiques ， Decades 1 et II. Ann. Sc. Sc. Na t. Bo t.， ser. 4， 14: 167-185. Tripodi ，Universita di Messina ，It aly ， for their help in Neumann K. 1970. Einkemiges Protonema bei Bryopsis und collecting collecting the materials. The visit ofM. C. to It aly was Pseudobryopsis myura. Helgolander wiss. Meeresunters. 20: 20: 213-215. made possible through a grant from the Bilateral Okamura K. 1936. Nippon Kaisou-shi. Uchida-Roukakuho ， Programs of Japan Society for the Promotion of Tokyo. Okuda K.， Enomoto S. and Tatewaki M. 1979. Life history of Science with the National Research Council ofltaly. Pseudobryopsis Pseudobryopsis sp. (Codiales ，). Jpn. J. Phyco l. 27: 27: 7-16. References References 01tmanns F. 1904. Mo 中hologie und Biologie der Algen. Bd.1. Chihara Chihara M. ， Kobara T. and 1riki Y. 1982. Life histories and cell G. Fisher ，Jena. wall wall constituents of the B η opsis-Derbesia complex (Class Provasoli L. 1966. Media and prospects for the cultivation of Chlorophyceae). Chlorophyceae). Acta Phytotax. Geobo t. 33: 41-54. marine algae. 1n Culture and ωllection 01 algae (Watanabe

一一一一一，一一一一一 and 一一一一一 1988. Li fe cycle and cell wall A. and Hattori A. eds ふProc.Japan 町 U.S. Conf. Hakone. Jap. constituent constituent of two species of Trichosolen ， T. myura and T. Soc. Plant Physio l. 63-75. hainanensis hainanensis (Chloeophyceae ，). of Abstracts Rietema H. 1969. New type of life history in Bryopsis Th ird 1ntemational Phycological Congress ，Melboume ，Aus- (Chlorophyceae ，Caulerpales). Acta Bo t. Neer l. 18: 615- tralia. tralia. 619. Coleman A. W.1982. Th enuclearcellcycleinChlamydomonas 一一一一一 1975. Comparative investigations on the life-histories (Chlorophyceae). (Chlorophyceae). J. Phyco l. 18: 192-195. and reproduction of some species in the siphonous green Feldmann J. 1937. Les algues marines de la cote des Alberes. 1- algal generaBryopsis andDerbesia. Thesis. Rijksuniversiteit III ，Cyanophycees ，Chlorophycees ，Pheophycees. Rev. AI- Te Groningen. Verenigde Reproduktie Dedrijven ， go l. 9: 141-335. Groningen ， 130 pp. 一一一一一 1969. Pseudobryopsis myura and its reproduction. Taylor W. R. 1962. Observations on Pseudobryopsis and Amer. Amer. J. Bo t. 56: 691-695. Trichosolen (Chlorophyceae ，) in America. Huizing Huizing H. J. and Rietema ， H. 1975. Xylan and mannan as cell Brittonia ， 14: 58-65. wall wall constituents of different stages in the life-histories of Yendo K. 1915. Note on algae new to Japan II I. Bo t. Mag. some siphonous green algae. B r. Phyco l. J. 10: 13-16. Tokyo 29: 99-117. 一一一一一一一一一- and Sietsma J. H. 1979. Cell wall constitu-

千原光雄，高原隆明:イタリア産ニセハネモの培 養と生活史 イタリアのナポリ沖にあるイスキア島とイタリ ンス産のニセハネモのそれよりもはるかに大きい. ア半島南西部にあるシシリー島で採集したニセハ ニセハネモは雌雄同株で，雌雄の配偶子はそれぞ ネモ Trichosolen myura (= Pseudohl ァ'opsis myura) れ別々の配偶子嚢内に生じる.雌雄の配偶子は接 の形態と，培養による生活史の研究結果を報告し 合して小さな旬旬糸状体に発達する.糸状体はま た.イタリア産のニセハネモの配偶子嚢は，フラ ばらに分枝し，細胞糸の所々にくびれをもっ. 84 植物研究雑誌第70 巻第2 号 平成 7 年 4 月

24 0 C と21 0 C の温度条件下において，糸状体から直 おいては Yendo (1 915) が日向からニセハネモの 接的にニセハネモの藻体が発達する. この結果は 生育を記録している. しかし，宮崎県串間沖の賓 Mayhoub (1 974) が報告したシリア産のニセハネ 垂島から遠藤によって採集された標本にはニセハ モの研究結果と一致する.ニセハネモ属の生活史 ネモ属特有の配偶子嚢が全くみられず， しかも小 と細胞壁構成糖から判断すると，ニセハネモ属と 羽枝がニセハネモ属のそれよりもはるかに太い. ハネモ属は極めて近縁であると思われる.日本に その標本はハネモ属 Bryopsis の一種と思われる.