A New Record of Sargassum alternato-pinnatum Yamada (Fucales, Phaeophyceae) from Taiwan

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1 Taiwania, 57(1): 71-76, NOTE A New Record of Sargassum alternato-pinnatum Yamada (Fucales, Phaeophyceae) from Taiwan Hirom ori Shimabuk uro '!", Masahir o Suzuki(2)and Masami Hamagu chi '!' I. National Research Institute of Fisheries and Environment of Inland Sea. Fisheries Research Agenc:l' Maruishi. Hatsukaichi City. Hiroshima Pref ecture Japan. 2. Departm ent of Elementary Education. Tsuru University Tahara, Tsuru. Yamanashi Pref ecture Japan. * Corresponding author. Tel: ; Fax: ; bukuro@ajji'c.gojp (Manuscr ipt received 8 August 20 I0; acce pted 13 June 20 I I) ABSTRACT: This report describ es Sargassum alternato-pinnatum Yamada as a newly reco rded spec ies in Ta iwan. The spec imens for this study were co llected from a shallow tidepoo l in Lan-yu, Taiwan. This spec ies is charac terized by the follow ing featu res: (l) sma ll discoid hold fast, (2) terete primary branches, (3) sharp spines arisi ng from surface of branches, (4) leaves that furca te 1-3 times, (5) sphe rical vesicles around the apex, (6) pseudozygocarpic receptacles wit h leaves or vesic le-like tissues, and (7) male and fema le conceptac les scattered wit hin the recept acles. In this report, we also present a line drawing and photographs for the ident ifica tion of S. alternato-pinnatum. KEY WORDS: Lan- Yu, mar ine algae, new record, Sargassaceae, Sargass um alternato-pinnatum. INTRODUCTION Me mbers of the ge nus Sargassum, the most spec ies-rich genus of the macroalgae, are widely distribut ed thro ughout the world from the subarctic to the trop ics. Sargassum species play a very important ro le in the marine ecosystem because seaweed beds co mposed of these organisms serve as nursery gro unds, i.e., egg-laying sites an d fee ding grounds, for vario us fishes and she llfishes (O kuda, 2008). Th erefore, these species need to be studie d in order to beller und erstand the coastal ecosystems. Man y species of ge nus Sargassu m have been found in Ta iwa n because thi s country is located betw een the tropi ca l and subtropica l region s, at the very cent er o f distribution of these spec ies. Thirty- four spec ies of the ge nus Sargassum have been record ed in Taiwan (C hou and Chiang, 1981; Lewis and Norris, 1987). Recently, Huang (2003) reported Hizikia fusiformis ( Harvey) Okamura, currently designate d as Sargass um fusiforme (Harvey) Setchell, as a newly recorded species from Taiwan. Firs tly, Sargassum alternato-pinnatum was described by Yamada (19 42) based on the specimen co llec ted from Aburatsu, Miyazaki Prefecture, Jap an. According to the speci men s housed in the herbarium at the Graduate Sc hoo l of Science, Hok kaido Unive rsity, Japan, this spec ies was distributed from Kii Peninsul a to Ama mi Island in Southern Japan. There was no report that the growth of th is spec ies in the other site and adjacent wa ters. However we co llec ted the S. alternato-pinnatum- uee speci mens (Fig. I) fro m Lan -Yu Township, Taiwan. In this paper, we present de tailed morph ological and anatomical observations of this spec ies. MATERIALS AND METHODS All speci mens were co llected from Crocodile Rock (22 0 5' N, ' E), Lan-Y u Township, Taid ong Co unty, Ta iwa n ( Fig. I ) at May 24, 2009 and preserved in 10% forma lin/seawater. Vo uc her herbarium speci me ns for thi s spec ies we re dep osited at the Departm ent of Botany, Na tiona l Muse um of Nature and Science, Japan (TNS-AL #). Spec ime ns from the herbarium at the Graduate Schoo l of Sc ience, Hokk aid o University, Japan (SAP #) and Nationa l Research Institute of Fishe ries and Env iro nme nt of Inland sea (FEIS #) we re also use d in this study for co mpa ring morp hologica l observatio ns. The morpholog ical features of all samples we re observed both macroscop icall y and microscopically using a stereomicroscope (O lymp us SZX7). Hand-sectioned receptac le specimens were observed under a biological microscope (Nikon Eclipse E600). All images were imported into Adobe" Photo'Shop" CS for plate assembly. RESULTS Sargassum alternato-pinnatum Ya ma da Yamada, 1944; Yos hida, 1988 ; Aji saka et al Figs. 2-4 Synony m: Sargass um asymmetricum Yamada

2 Taiwania Vol. 57, NO N Taiwan St rait 50 km 120 EI 2km Taiwan lan-yu ( Orchid Island ) E Fig. 1. Map of Lan-yu (Orchid Island), Taiwan. Black circle indic ates the sample-collection site of this study. Type locality: Aburatsu, Nichinan City, Miyazaki Prefecture, Japan. Geographical distr ibut ion : Jap an (Honshu, Shikoku, Kyushu, and Okinawa Islands) and Taiwan Spec imen exa mined: FROM TA IWAN: TNS-AL (Ma y 24, 2009) and SAP (May 24, 2009) collected from Crocodile Rock (22 0 5' N, ' E), Lan-Yu Tow nship, Taidon g County. FROM JA PAN: SAP (Holotype, Fig. 2) (August 1940) collected from Aburatsu, Nichinan City. Miyazaki Prefect ure; SAP (Ma y 20, 1954) collected from Usuki, Arnami City, Kagoshima Prefecture; SAP (June 12, 1980) collected from Natsui, Shibushi City. Kagoshirna Prefecture. FEIS (June 6, 1980) collected from Seseguch i, Kagoshima City, Kagoshima Prefecture. Thallus, 20 to 60 em tall (F ig. 3A) ; sma ll discoid hold fast, 5-12 mm diameter; stem, short and terete with a warty surface and arising from the center of the holdfast, 3-10 mm long, and 2-3 mm diameter. Leaves, linear to narrow lanceolate, I - 4 em long and 5 mm wide, dentate and slightly wavy margin; acute apex; furcatin g I - 3 times, rarely non-furcating and simple; basal port ion of leaves, asymmetrical to cuneate; midrib attached to the apex; cryptostomata scattered on the leaf surfaces (Fig. 38); Vesicles, spher ica l, of 3-7 mm diameter, usually obse rved around the apex of the branches, rarely crowned; stalks with a similar diameter as that of the ves icles or less, and rarely spiny (Fig. 3C); cryptostomata scattered on the surface ; medull ary filaments not present within the ves icles (Fig. 3D). Primary branches arise spirally from the apical part of the stem; prim ary branches, terete, 2-3 mm diameter, usually with short and ofte n bifurcating spines arising on the surface (F ig. 3E); Seco ndary branches, 3-20 em long, with I - 2 mm diameter arising spirally from the prim ary branches at 2-15 em interva ls. Plant s are monoecious. Receptacles arise fro m the axil of the leaves on the branches, terete or slightly compresse d, furc ated I to seve ral times, warty sur face, 2-5 mm long, and I mm wide; the pseud ozygocarpic receptac les had leaves or vesicle-like tissues (Fig. 3F). Male and female conce ptacles were scattere d within the receptacles and were urn in diameter. Oogo nia were urn in diameter (Fig. 3G). DISCUSSION Sargassum alternato -pinnatum was first described by Yamada ( 1942), who found it in Miyazaki Prefectur e, Japan. The spec ies is character ized by the following features: ( I) sma ll discoid hold fast, (2) terete pr imary branches, (3) sharp spines arisi ng from the surface of branches, (4) leaves furca ting I - 3 times, (5) spherical vesi cles around the apex, (6) pseud ozygocarpic rece ptac les with leaves or vesicle-like tissues, and (7) male and fema le co ncepta clcs scattered within the rece ptacles. We collec ted S. altemato-pinnatum-use spec imens from tide pools at Crocodile Rock, located in the north ern part of Lan-Yu Tow nship, Taiwan. We identified these Ta iwanese speci mens as S. alternato-pinnatum by compari ng the morphological charac teristics of these specimens collec ted from Japan and the holotype spec imen. S. alternato-pinna tum is similar to S. po lycys tum in that both species have small lanceolate leaves and sharp spines on the surface of the branches. Huang (2006) also recorded S. polycystum from Croco dile Rock, the same regio n from where we collecte d S. alternato-pinnatum of this study. However, S. alternato-pinnatum has the following characteristics that are different from those of S. polycystum: furcated leaves and monoecious recep tacles. In addition, S. po lycystum has rhizoi da l branches. 72

3 March Shima bukuro ct al. : Sargassum a!ferj1afo-p iililuiiiiii from Taiwan A fi S 5cm Figs. 2. Holotype specimen of Sargassum altern ato-pinnatum Yamada. (SAP 23465, Aburatsu, Miyazaki Prefecture, Japan. August 1940). A: Thallus of the holotype specimen. B & C: A closer view of the leaves, vesicles, and branches of the holotype specimens. 73

4 Taiwania Vol. 57, No. I 1 em Fig. 3. Sargassum alternato-pinnatum Yamada, Lan -yu Township, Taidong County, Taiwan (May 21, 2009). A: Thallus. B: Leaves of various shapes. C: Vesi cles around the apex. D: Cross section of the su rface of a ves ic le. Area enclosed by the dotted lines is the inner portion of the vesicle. E: Sp iny branches. F: Androgynous receptacles. F: Transverse sec tion of a receptacle. F indicates female conceptacl es. M ind icates male conceptacle. Some qu antitative trait s of the morphological fea tures (e.g., len gth of thallus an d leaves) di ffered slightly betwee n the Ta iwanese S. alternato-pinnatum and the typica l Japanese S. alternato-pinnatu m. Phenotyp ic plas ticity occurs in marine algae because of an interac tion with the environme nt, and this interaction changes the ge ne tic characteristics. A co mpa rat ive ge ne tic ana lysis of the Ta iwanese and Jap anese S. alternato-pinnatum will be perform ed in the near future (Uwai et ai., 2009). S. alternato-pinnat um is known to be distributed in the ce ntra l reg ions of the Honshu, Shikok u, Kyushu, and Okinawa islands of Japan. However, in this study, this species was reported from Lan- Yu Township in Taiwan. At present, Lan -Yu is the southern limit of the dis trib utio n of S. alternato-pinnatum. The Kurosh io Current flows nort hwa rd along the eastern coast of Taiwan and the Okinawa Island to the centra l region of Honshu in Japan. Lan- yu is located in the path of the Kur oshio Current. It appears that S. alternato-pinnatum is distribut ed along the Kuroshio Current. In recent years, global environmental changes are ca using a shift in the geographical distribut ion of all Sargassum spec ies. We wi ll con tinue to moni tor seaweeds including those of the genus Sargassum on the bord er of the tropical and subtro pical regions in Ta iwan. ACKNOWLEDGMENTS We since rely thank Prof. Tateo Horiguchi and Asso. Prof. Kazuhiro Kogame, Graduate School of Science, Hokkaido University, and Dr. Taijyu Kitayarna, Department of Botany, National Museum of Nature and Science, for giving us the privilege to examine the specimens housed in the herbaria of thei r institu tions. We also thank Dr. Sun Zhongrnin, Kobe 74

5 March,2012 Shimabukuro et al.: Sargassum alternato-p innatum from Taiwa n C - 0 :. '... '.' 5 mm D Fig. 4. Drawing of Sargassum altemato-pinnatum Yamada collected in this study. A: Thallus. B: Leaves. C: Vesicle. D: Spiny branches. E: Receptacle. University Research Center for Inland Seas, for preparing the Chinese manu script. LITERATURE CITED Ajisaka, '1'., T. Nor o, G. C. Jr Trono, Y. M. C hia ng and T. Yoshida Several Sargassum species (sub ge nus Sargassumv in East Asia with furcately branching leaves. In: Abb ot, I. A. (ed.) Taxonomy of Economic Seaweeds 4: University of California. Ca liforn ia Sea Grant College System. U.S.A C hou, H. N. and Y. i\1. C hia ng The Sargass um of Taiw an. Acta Oceanograph ica Taiwani ca Science Reports of the ational Taiw an Unive rsity. 12: Huang, S. F Hizikia fusiformis (Harvey) Okamura: a new record for Ta iwan (Heterokontophyta, Fucales, Sarg assaceae). J. atl. Taiw an Museum. 56 : 1-5. Huang, S. F Benthic mar ine algae of Lan-Yu (Orchid Island), Taiw an. J. Natl. Taiwan Museum. 59 : Lewi s, J. E. and J. No r r is A history and annotated account of the benthic marin e algae of Taiwan. Smithso n. Contrib. Ma r. Sci. 29: Okuda, K Coastal environment and seaweed-bed ecology in Japan. Kuro shio Science. 2: Uwai, S., K. Kogarne, G. Yoshida, H. Kawai and T. Aj isa ka Geographical genetic structure and phylogeography of the Sargassum hornerilfilicinum complexin Jap an, based on the mitochondri al co.d hapl otype. Mar. BioI. 156:

6 道會 現 Taiwania Vol. 57, No. 1 Ya ma da, Y Notes on Sa rgass li l/i 仕 om the southern parts of Japan, III. J. Jap. Bot. 18: Ya ma da, Y Diagnoses of new SargasslIl/Is from Japan. Scientific Papers of the Institute of Algologica l Research, Faculty ofscience, Hokkaido Imperial University. 3: Yoshida, T Japanese and Taiwa nese species of Sw 古 assli 1/I subgenus Sargassllm. In: A b bots LA. (ed.) Taxonomy of Economic Seaweeds 2: University of Ca l i fo rn 泊, California Sea Grant College System. U.S.A 臺 j 彎產馬尾藻之新記錄種 Sargass um alternato-p innatum Yam ada Hiromori S h imab u k u ro(l*), M asah io S uzuk i(2) and Masa m i Hamaguchi(l) 1. National Research Instilllte of Fisheries ω/(1 Envirolllnel1l of Inland Sea. Fish er 的 R esearch Agency, 2ιμ-1 7λ- 5 A仰 t. Gωn 叫 1 Haωts 可叮 S II 爪 ka ιu 叫 tυic h 叫 i Cο':itJ 吵 " Hiroshima Pref eclllre, , Japan. 2. The Depart ment of Elel/lel1l 的! Edllcation, TSllru Un ive l 訕 " Tahara, TSllru C i ty. 只 II l1 anash i P I' 拼叮 IlIre, , Japan * 通信作者 Te l : : Fax: : El/lail: bllkllro@ajji c.gojp (~ 文稿日期 : 年 8 月 8 日 ; 接受日期 : 2011 年 6 月 13 日 ) 摘要 : 本文對臺 j 弩之新記錄馬尾藻 Sw 苦的 s lim a/lernalo-p innalllll1 Y amada 進行闡述 標本 採集於藺嶼海岸淺潮池中 該種具有以下之特徵 : 一 小型盤狀固著器 : 二 主軸呈圓柱形 : 三 刺棘生於藻枝表面 ; 四 藻葉一至三次分叉 ; 五 氣囊為球形且尖端鈍圓 ; 六 生殖托與藻葉或似氣囊結構同柄混生 : 七 雌雄生殖巢散生於同一生殖托 本文提供繪圖及相片作為鑑定該種之依據 關鍵詞 : 蘭嶼 新記錄種 馬尾藻料 Sargass lim a /lern alo -pinna lll lj1 76