Botanica Marina 48 (2005): 46–51
2005 by Walter de Gruyter • Berlin • New York. DOI 10.1515/BOT.2005.005 Ulva fasciata Delile (Ulvaceae, Chlorophycota): a species newly introduced into Pacific Mexico Raúl Aguilar-Rosas1,*, Luis E. Aguilar-Rosas2 and Francisco F. Pedroche3 Facultad de Ciencias Marinas, Universidad Autónoma de Baja California, Apdo. Postal 453, 22830, Ensenada, Baja California, Mexico, e-mail: raguilar@uabc.mx 2 Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Apdo. Postal 453, 22830, Ensenada, Baja California, Mexico 3 Departamento de Hidrobiologı́a, UAM–Iztapalapa, Apdo. Postal 55-535, México, D.F. 09340, Mexico and University Herbarium, University of California 1001 VLSB  2465, Berkeley, CA 94720-2465, USA 1 *Corresponding author Abstract Ulva fasciata Delile is reported for the first time as an introduced species along the coast of the Baja California Peninsula. In 2002–2003, populations of U. fasciata were observed at only three sites (Monalisa Beach, El Faro Beach and mouth of Punta Banda Estuary) on the eastern side of Todos Santos Bay, Baja California, Mexico. The variation in mean thallus size suggests that this species attains maximum development during late summer and early autumn (September), gradually decreases during autumn–winter and disappears during spring (April). Reproductive plants were observed, especially in the warm months (summer–autumn), when seawater temperatures can reach 248C. A detailed review of specimens housed in Mexican herbaria revealed that U. fasciata is widely distributed along the Mexican Pacific coast, growing on rocks in the midtidal and upper intertidal zones. A detailed description of the vegetative and reproductive structures is provided. Keywords: Baja California; Chlorophycota; introduced species; Pacific Mexico; Ulvaceae; Ulva fasciata. Introduction As a result of extensive floristic studies of the macroalgae that inhabit Todos Santos Bay, Baja California, Mexico, we report the presence of Ulva fasciata Delile, a new record for the area of what we consider an introduced species. U. fasciata was originally described by Delile (1813) from specimens collected in Alexandria, Egypt. It is widely distributed in the temperate and tropical waters (Atlantic Ocean, including the Caribbean Sea, and Indian Ocean). In the Pacific Ocean, it is found on the coasts of Japan, China, Philippines, Vietnam, Singapore, Indonesia and Galapagos Islands. It is considered as an introduced species in Hawaii and Australia, the probable vector of introduction being ballast water and/or fouling on ships’ hulls (Saifullah 1977, Phillips 1988, Silva et al. 1996). In Hawaii, this species is known as ‘‘pahapaha’’ or ‘‘limu pahapaha’’ and is consumed as food in salads or soups. In Japan, it is used as fertilizer and fodder (Arasaki and Arasaki 1983, Abbott 1984). For the Pacific coast of Mexico, 19 species of Ulva are currently recognized, 12 of which have been reported for the west coast of Baja California (Pedroche et al. 2004). U. fasciata has been found only once in Pacific Mexico by Mateo-Cid and Mendoza-González (2001) in their studies on the coast of Oaxaca (Santa Elena Beach). In the present paper, we report U. fasciata as an introduced species for the west coast of Baja California. Furthermore, a review of specimens housed in Mexican herbaria revealed that U. fasciata is widely distributed along the west coast of Pacific Mexico. We provide a detailed description of the vegetative and reproductive characteristics, as well as of its distribution in the study area. Materials and methods The first specimens of Ulva fasciata were found at Monalisa Beach, on September 22, 2002. One month later, we located other populations at El Faro Beach and the mouth of Punta Banda Estuary, in Todos Santos Bay (Figure 1). To determine the monthly variation in the thallus size at Monalisa Beach, we measured 40 plants collected haphazardly from September 2002 to March 2003. The thalli were measured from the basal structure to the apical portion of the largest blade of each individual. Samples were then preserved in 4% formalin/seawater for laboratory analysis. The thalli of U. fasciata were identified using compound and stereoscopic microscopes (Meiji ML 2000, Meiji Techno Co. Ltd., Japan), using descriptions published in Krishnamurthy and Joshi (1969), Womersley (1984), Phillips (1988) and Schneider and Searles (1991). Photographs of sections were taken on a Zeiss microscope (Axioscop 40, Goettingen, Germany) with a digital camera (Sony DSC-S85, Tokyo, Japan). Herbarium specimens are deposited in the CMMEX Herbarium at the Faculty of Marine Science of the Autonomous University of Baja California (Holmgren et al. 1985). Specimens of U. fasciata were found in the ENCB (National School of Biological Science, IPN) and FCM (Faculty of Marine Science, Autonomous University of Sinaloa) herbaria. We also compared the thalli collected with U. fasciata specimens from the Hawaiian Islands housed at the University of California (UC), Berkeley. R. Aguilar-Rosas et al.: Ulva fasciata Delile: a species newly introduced into Pacific Mexico 47 Figure 1 Ulva fasciata: study area and collecting sites. Results and discussion Class Ulvophyceae; Order Ulvales; Family Ulvaceae: Ulva fasciata Delile (Figure 2) Vegetative structure Thallus in blades, distromatic, 3–72 cm tall, from dark green to yellowish in color, attached to the substratum with a small basal disk, stipitate with a cuneate base, expanded in the upper part and irregularly divided in numerous segments or large lobes. It is linear to lanceolate, simple or ramified, flat or slightly undulate with irregular dichotomies; lobes are 1–4 cm wide with the basal part constricted and tapering fairly evenly to a slender tip 1–3 mm wide. The margins are relatively smooth to slightly irregular with occasional coarse microscopic marginal teeth or spinous projections. In surface view, the cells are polygonal, isodiametric to elongate, 15–20 mm long and 6–10 mm wide; one or two pyrenoids per cell. In transverse section, the blades are 45–70 mm thick along the margins and 60–130 mm in the center. The cells are 20–40 mm long and 10–20 mm wide. Rhizoidal cells are round, 18–30 mm wide, with hyaline filamentous projections towards the substrate. Material examined Playa Monalisa, September 22, 2002, R. Aguilar-Rosas, on rocks; Playa El Faro, October 21, 2002, L.E. Aguilar-Rosas, on rocks; Boca Estero de Punta Banda (Estero Beach), October 21, 2002, L.E. Aguilar-Rosas; Playa Monalisa, November 6, 2002, R. Aguilar-Rosas and L.E. Aguilar-Rosas, on rocks; Playa Monalisa, December 2, 2002, L.E. Aguilar-Rosas and R. Aguilar-Rosas, on rocks. Playa El Sábalo, May 6, 1970, J.L. Tirado (ENCB 3442); Playa Santa Elena, May 8, 1997, L.E. Mateo-Cid and C. Mendoza-González (ENCB 14986); Cabo Corrientes, September 4, 1981, G. Chávez (ENCB 5168); Playa La Barrita, July 15, 1973, R. Cruz (ENCB 3037); Casa del Marino (Punta Chile), June 20, 1987, C. Valdéz and A. Balderas (FCM 1444), as U. dactylifera Setchell et Gardner; Punta Cerritos (Playa Cerritos), May 21, 1987, C. Valdéz and A. Balderas (FCM 1441), U. dactylifera Setchell et Gardner; El Faro (Cerro El Crestón), January 29, 1999, M.J. Ochoa (FCM 3037), U. dactylifera Setchell et Gardner; Isla de Piedra, February 20, 1988, A. Balderas and C. Valdéz (FCM 1373), U. dactylifera Setchell et Gardner. Habitat and seasonality Reproduction Reproductive tissue is light brown in color, at the margins of the lobes; when spores or gametes are released, cell contents are evacuated completely and the tissue becomes transparent. In transverse section, the reproductive blades are 50–80 mm thick along the margins. Ulva fasciata plants grow on rocks in the midtidal and upper intertidal zones. They attain a maximum development during late summer and early autumn (September), gradually decrease during autumn–winter and disappear during spring (April). 48 R. Aguilar-Rosas et al.: Ulva fasciata Delile: a species newly introduced into Pacific Mexico Figure 2 Ulva fasciata: specimen collected on September 22, 2002, at Monalisa Beach, Baja California. Scale bars2 cm. Comments The first specimens of U. fasciata were found in the midtidal and intertidal zones on rocks at Monalisa Beach. The thalli were large, up to 72 cm long, and fertile. We observed that in this area U. fasciata was always the dominant species; associated algae were Codium fragile (Suringar) Hariot, Pterosiphonia dendroidea (Montagne) Falkenberg, Polysiphonia mollis Hooker et Harvey, Hypnea valentiae (Turner) Montagne, Centroceras clavulatum (C. Agardh) Montagne, Bonnemaisonia hamifera Hariot and Endarachne bingamiae J. Agardh. In general, Mexican plants of U. fasciata show the same morphological, anatomical and reproductive characteristics found in other populations around the world (Saifullah 1977, Krishnamurthy 2000). The variation in mean thallus size (Table 1) suggests that maximum development of the Monalisa Beach population occurs in late summer and early autumn (September), with thalli up to 56 cm, gradually decreasing in autumn–winter and disappearing in spring (April). The thallus sizes of our specimens fit the description of plants from Australia, China and Jamaica, with lengths ranging from 5 to 100 cm (Chapman 1961, Tseng 1983, Womersley 1984). Individuals from India, Tanzania and the southeastern coast of the United States, however, can reach 200 cm in length (Subbaramaiah et al. 1967, Subbaramaiah 1970, Shunula 1983, Schneider and Searles 1991, Krishnamurthy 2000, Sahoo et al. 2003). The width of the lobes, the thickness of the vegetative portion of the thallus, and the vegetative cell size in surface and transverse views are similar to those of other populations in the Atlantic, Indian and western Pacific Oceans (Chapman 1961, Krishnamurthy and Joshi 1969, Tseng 1983, Womersley R. Aguilar-Rosas et al.: Ulva fasciata Delile: a species newly introduced into Pacific Mexico Table 1 Ulva fasciata: mean length of thalli at Monalisa Beach, Baja California (mean"SD, ns40). Season Month Length (cm) Late summer/autumn September October November December January February March April 56.00"8.20 48.00"10.60 35.10"8.90 24.16"8.30 24.10"4.50 4.69"1.25 3.00"0.89 – Winter Spring 1984, Schneider and Searles 1991, Amjad and Shameel 1993, Krishnamurthy 2000). The samples of U. fasciata resemble the specimens of U. dactylifera, U. nematoidea (sU. costata) and U. taeniata whose thalli are divided into large linear or undulate lobes. Our samples differ in that U. dactylifera has a digitate thallus with lobes growing from an orbicular to reniform basal portion; in U. nematoidea the laminar segments have a visible midrib, with strongly ruffled margins; and in U. taeniata the thalli have lobes differentiating from a discoid base, densely ruffled and commonly spirally twisted with dentate margins in the lower parts (Setchell and Gardner 1920, Abbott and Hollenberg 1976, Amjad and Shameel 1993, Gabrielson et al. 2000, Wynne 2002). Recently, Hiraoka et al. (2003) described a new species called Ulva ohnoi Hiraoka et Shimada from Japan, which is closely related to U. fasciata, U. retinacula Forskål and U. spinulosa Okamura. All these have microscopic and marginal teeth, with bright green colored thalli. These authors compared morphology, life histories and molecular data, describing U. fasciata as algae with thalli divided at the base, giving rise to narrow and branched blades. On the other hand, U. ohnoi, U. reticulata and U. spinulosa show orbicular or ovoid-branched thalli with blades of different shapes at the mid or upper end (Hiraoka et al. 2003). The general morphology of U. fasciata specimens from the Mexican Pacific collected agrees with that of Japanese thalli. The identity of U. fasciata is confirmed by the comparative analyses of our material with specimens of this species collected from the Hawaiian Islands, deposited at UC (W.J. Gilbert No. 9526, 4/24/1959, Hanamaula Bay, Kauai, UC 273644; G.F. Papenfuss No. 10231, 4/4/1942, Waimea Bay, Oahu, UC 1470808; J. Chin-Chih No. 1611, 5/22/1936, Black Point, Oahu, UC 764341). Type material was not considered in this study. Culture studies have shown that the life cycle of U. fasciata is biphasic with an isomorphic alternation of generations (Migita and Fujita 1987). The diploid sporophyte produces quadriflagellate spores, while the haploid gametophyte releases biflagellate gametes (Smith 1947, Tanner 1981, Bold and Wynne 1985, van den Hoek et al. 1995). Reproductive plants were commonly observed in the material collected from Baja California, especially in the warm months of summer and autumn, when the seawater temperatures can reach 248C (Grijalva-Chon et al. 1985). As a result of the spore/gamete release, the thalli show biomass loss starting from the lateral and terminal margins, and this is reflected in a decrease in thallus size, which reaches a minimum in March; in April the plants disappear (Table 1), when water temperature is low, i.e., not above 178C (Grijalva-Chon et al. 1985). Thallus reduction due to propagule release (spores or gametes) also has been observed in the populations of U. fasciata from India (Subbaramaiah 1970). Previous floristic studies in Todos Santos Bay (including the harbor and Punta Banda Estuary) reported the presence of U. angusta, U. californica, U. costata, U. dactylifera and U. lactuca (Devinny 1978, Aguilar-Rosas and Bertsch 1983, Aguilar-Rosas et al. 1985, MendozaGonzález and Mateo-Cid 1985). These studies were conducted between 1973 and 1983, and did not report the presence of U. fasciata in the area. Populations of U. fasciata currently occur at only three sites (Monalisa Beach, El Faro Beach and mouth of Punta Banda Estuary), on the eastern side of Todos Santos Bay. This bay covers quite a large area and has been extensively searched, but we have not observed plants in surrounding areas, such as in Ensenada harbor or Cabo Punta Banda. We therefore speculate that this species was recently introduced into Baja California waters, and shows a seasonal behavior. The discovery of U. fasciata in Todos Santos Bay is not very surprising, as other introduced species have been recorded for this area, e.g., Sargassum muticum (Yendo) Fensholt (Aguilar-Rosas and Aguilar-Rosas 1993) and more recently Porphyra suborbiculata (Broom et al. 2002, Aguilar-Rosas and Aguilar-Rosas 2003). The occurrence of U. fasciata in Todos Santos Bay may be correlated with heavy traffic of commercial vessels and cruise ships to the port of Ensenada (Casarrubias-Garcı́a 2001). Port Table 2 Ulva species with blades reported for the west coast of Baja California. Species Ulva Ulva Ulva Ulva Ulva californica Wille dactylifera Setchell et Gardner expansa (Setchell) Setchell et Gardner lactuca Linnaeus nematoidea Bory de Saint Vincent Ulva rigida C. Agardh Ulva tanneri H.S. Hayden et J.R. Waaland Ulva fasciata Delile 49 Reference (first record in Baja California) Dawson 1945 Aguilar-Rosas and Bertsch 1983 Dawson 1962 (as U. latissima Linnaeus) Dawson 1945 Aguilar-Rosas and Bertsch 1983 was U. costata (Howe) Hollenbergx Aguilar-Rosas and Pacheco-Ruı́z 1986 Aguilar-Rosas and Bertsch 1983 (as Chloropelta caespitosa Tanner) This study 50 R. Aguilar-Rosas et al.: Ulva fasciata Delile: a species newly introduced into Pacific Mexico areas with international traffic are considered as places for species introduction, with ship hulls or ballast water acting as vectors (Ribera and Boudouresque 1995). With the presence of U. fasciata on the northwestern coast of Baja California, the number of Ulva species with blades recorded for the Mexican Pacific increases to eight (Table 2). However, a comparative study of the species in Baja California is necessary to better establish the morphological, cytological and reproductive criteria to identify and define these species. A molecular phylogenetic analysis of these taxa would help and clarify the species boundaries of these entities, since some of these taxa have similar morphological characteristics and show a high degree of phenotypic plasticity under different environmental conditions (Arasaki 1984, Tanner 1986, Stewart 1989, Chen and Shih 2000, Hayden and Waaland 2002, Shimada et al. 2003). Only one previous record of this species existed for Pacific Mexico (Mateo-Cid and Mendoza-González 2001), corresponding to a tropical region (Santa Elena, Oaxaca). However, based on the present records including the field collections from Baja California, and earlier herbarium specimens, we can say that the distribution of U. fasciata extends throughout most of the Pacific coast of Mexico (Figure 1). It is necessary to monitor the coast of Baja California to determine how fast this species is colonizing nearby areas and its impact on other algal communities, and perhaps to prevent its introduction to other areas of the Pacific coast of North America (USA and Vancouver), were U. fasciata does not occur (Hansen 1997, Gabrielson et al. 2000). Acknowledgements We thank Filiberto Núñez Cebrero for assistance in the field collection and sample preservation, as well as the following persons and institutions for the loan of herbarium specimens used in this study: Paul C. Silva, curator of the UC Herbarium (University of California at Berkeley); M. Ochoa, curator of the FCM Herbarium (Universidad Autónoma de Sinaloa); and C. Mendoza-González, curator of the ENCB Herbarium (Instituto Politécnico Nacional). Special thanks to Dr. Brigitte Gavio for the English translation of this manuscript. Funding was provided by the Universidad Autónoma de Baja California. We also acknowledge two anonymous reviewers for their useful comments on the manuscript. References Abbott, I.A. 1984. Limu: An ethnobotanical study of some edible Hawaiian seaweeds. Pac. Trop. Bot. Gard., Kauai, Hawaii. pp. 35. Abbott, I.A. and G.J. Hollenberg. 1976. Marine algae of California. Stanford University Press, Stanford, California. pp. 827. Aguilar-Rosas, R. and L.E. Aguilar-Rosas. 1993. Cronologia de la colonización de Sargassum muticum (Phaeophyta) en las costas de la Peninsula de Baja California, México. Rev. Inv. Cien. 4:41–51. Aguilar-Rosas, R. and L.E. Aguilar-Rosas. 2003. El género Porphyra (Bangiaceae, Rhodophyta) en la costa Pacifico de México. I. Porphyra suborbiculata Kjellman. Hidrobiológica 13: 51–56. Aguilar-Rosas, L.E. and H. Bertsch. 1983. Algas verdes (Chlorophyta) de la Bahı́a Todos Santos, Baja California, México. Cienc. Mar. 9: 111–124. Aguilar-Rosas, L.E. and I. Pacheco-Ruı́z. 1986. Variaciones estacionales de las algas verdes (Chlorophyta) de la costa noroccidental de la peninsula de Baja California. Cienc. Mar. 12: 73–78. Aguilar-Rosas, L.E., E. Baltazar-Valenzuela and I. Pacheco-Ruı́z. 1985. Las algas marinas bentónicas de la rada portuaria de Ensenada, Baja California. Cienc. Mar. 11: 121–126. Amjad, M.T. and M. Shameel. 1993. Two new species and two new reports of Ulva L. (Ulvophyceae) from the coast of Karachi, Pakistan. Pak. J. Mar. Sci. 2: 5–16. Arasaki, S. 1984. A new aspect of Ulva vegetation along the Japanaese coast. Hydrobiologia 116/117: 229–232. Arasaki, S. and T. Arasaki. 1983. Vegetables from the sea. Japan Publications, Inc., Tokyo. pp. 196. Bold, H.C. and M.J. Wynne. 1985. An introduction to the algae. Structure and reproduction. 2nd edition. Prentice Hall, Englewood Cliffs, New Jersey. pp. 720. Broom, J.E., W.A. Nelson, C. Yarish, W.A. Jones, R. AguilarRosas and L.E. Aguilar-Rosas. 2002. A reassessment of the taxonomic status of Porphyra suborbiculata, Porphyra carolinensis and Porphyra liliputiana (Bangiales, Rhodophyta) based on molecular and morphological data. Eur. J. Phycol. 37: 227–235. Casarrubias-Garcı́a, A. 2001. Puertos, potencialidades y auge de los cruceros. Mexicoa 3: 102–111. Chapman, V.J. 1961. The marine algae of Jamaica. Part 1. Myxophyceae and Chlorophyceae. Bull. Inst. Jam. Sci. Ser. 12(1). pp. 159. Chen, Y.-C. and H.-C. Shih. 2000. Development of protoplasts of Ulva fasciata (Chlorophyta) for algal seed stock. J. Phycol. 36: 608–615. Dawson, E.Y. 1945. Marine algae associated with upwelling along the northwestern coast of Baja California. Bull. So. Calif. Acad. Sci. 44: 57–71. Dawson, E.Y. 1962. Benthic marine exploration of Bahı́a de San Quintı́n Baja California 1960–61. Marine and marsh vegetation. Pacific Naturalist 3: 275–280. Delile, A.R. 1813. Florae aegyptiacae illustratio. In France (Comisión d’Egypte). Description de l’Egypte, ou recueil des observations et des recherches qui ont été failes en Égypte pendant l’expédition de l’armée Francaise (1798–1801). Histoire naturelle 2. pp. 49–82, 145–320. Devinny, J.S. 1978. Ordination of seaweed communities: environment gradients at Punta Banda, Mexico. Bot. Mar. 21: 357–363. Gabrielson, P.W., T.B. Widdowson, S.C. Lindstrom, M.W. Hawkes and R.F. Scagel. 2000. Keys to the benthic marine algae and seagrasses of British Columbia, southeast Alaska, Washington and Oregon. Phycological Contribution Number 5, Department of Botany, University of British Columbia, Vancouver. pp.189. Grijalva-Chon, J.M., R. Castro-Longoria and M. Gregory Hamman. 1985. Temperatura y visibilidad en la Bahı́a de Todos Santos, B.C., México, octubre de 1982 a septiembre de 1983. Cienc. Mar. 11: 39–48. Hansen, G.I. 1997. A revised checklist and preliminary assessment of the macrobenthic marine algae and seagrasses of Oregon. In: (T.N. Kaye, A. Liston, R.M. Love, D.L. Luoma, R.J. Meinke and M.V. Wilson, eds) Conservation and management of native flora and fungi. Native Plant Society of Oregon, Corvalis. pp. 175–200. Hayden, H.S. and J.R. Waaland. 2002. Phylogenetic systematics of the Ulvaceae (Ulvales, Ulvophyceae) using chloroplast and nuclear DNA sequences. J. Phycol. 38: 1200–1212. Hiraoka, M., S. Shimada, M. Uenosono and M. Masuda. 2003. A new green-tide-forming alga, Ulva ohnoi Hiraoka et Shimada sp. nov. (Ulvales, Ulvophyceae) from Japan. Phycol. Res. 51: 17–29. R. Aguilar-Rosas et al.: Ulva fasciata Delile: a species newly introduced into Pacific Mexico Holmgren, P.K. 1985. Additions to index herbariorum, Part I. The herbaria of the world, Edition 7. Taxon 34: 735–738. Krishnamurthy, V. 2000. Algae of India and neighbouring countries I. Chlorophycota. Science Publishers, Inc., NH, USA. pp. 268. Krishnamurthy, V. and H.V. Joshi. 1969. The species of Ulva L. from Indian waters. Bot. J. Linn. Soc. 62: 123–130. Mateo-Cid, L.E. and C.A. Mendoza-González. 2001. Algas marinas bentónicas de la costa de Oaxaca, México. Ann. Esc. Nac. Cienc. Biol., Méx. 47: 11–26. Mendoza-González, A.C. and L.E. Mateo-Cid. 1985. Contribución al estudio florı́stico ficológico de la costa occidental de Baja California, México. Phytologia 59: 17–33. Migita, S. and Y. Fujita. 1987. The life history of Ulva fasciata Delile (Chlorophyceae, Ulvales) in culture. Jap. J. Phycol. 35: 226–230. Pedroche, F.F., P.C. Silva, L.E. Aguilar-Rosas, K.M. Dreckmann and R. Aguilar-Rosas. 2004. Catálogo de las algas marinas bentónicas del Pacı́fico mexicano I. Chorophycota. Universidad Autónoma de Baja California, Ensenada, Baja California. pp. 135. Phillips, J.A. 1988. Field, anatomical and developmental studies on Southern Australian species of Ulva (Ulvaceae, Chlorophyta). Aust. Syst. Bot. 1: 411–456. Ribera, M.A. and C.F. Boudouresque. 1995. Introduced marine plants, with special reference to macroalgae: mechanisms and impact. In: (F.E. Round and D.J. Chapman, eds) Progress in phycological research. Vol. 11. Biopress Ltd, Bristol. pp. 187–268. Sahoo, D., N. Sahu and D. Sahoo. 2003. A critical survey of seaweed diversity of Chilika lake, India. Algae 18: 1–12. Saifullah, S.M. 1977. Studies of the marine algae from Pakistan: Ulvales. Bot. Mar. 20: 521–536. Schneider, C.W. and R.B. Searles. 1991. Seaweeds of the southeastern United States: Cape Hatteras to Cape Canaveral. Duke University Press, Durham and London. pp. 553. Setchell, W.A. and N.L. Gardner. 1920. Phycological contributions, I. Univ. Calif. Publ. Bot. 7: 279–324. 51 Shimada, S., M. Hiraoka, S. Nabata, M. Lima and M. Masuda. 2003. Molecular phylogenetic analysis of the Japanese Ulva and Enteromorpha (Ulvales, Ulvophyceae), with special reference to the free-floating Ulva. Phycol. Res. 51: 99–108. Shunula, J.P. 1983. Biomass trends in Ulva fasciata Delile and U. pulchra Jaasund (Chlorophyta, Ulotrichales) in Dar es Salaam-Tanzania. Seaweed Res. Utiln. 6: 49–52. Silva, P.C., P.W. Basson and R.L. Moe. 1996. Catalogue of the benthic marine algae of the Indian Ocean. University of California Press, Berkeley, Los Angeles, London. pp. 1259. Smith, G.M. 1947. On the reproduction of some Pacific coast species of Ulva. Am. J. Bot. 34: 80–87. Stewart, J.G. 1989. Marine algae and seagrasses of San Diego County. California Sea Grant College, La Jolla, CA. pp. 197. Subbaramaiah, K., S.R. Kale and V. Krishnamurthy. 1967. Gametes and germlings of Ulva fasciata Delile. Curr. Sci. 5: 128–129. Subbaramaiah, K. 1970. Growth and reproduction of Ulva fasciata Delile in nature and in culture. Bot. Mar. 13: 25–27. Tanner, C.E. 1981. Chlorophyta: life histories. In: (C.S. Lobban and M.J. Wynne, eds). The biology of seaweeds. Blackwell Science, Oxford. pp. 218–247. Tanner, C.E. 1986. Investigations of the taxonomy and morphological variation of Ulva (Chlorophyta): Ulva californica Wille. Phycologia 25: 510–520. Tseng, C.K. 1983. Common seaweeds of China. Science Press, Beijing, China. pp. 320. Van den Hoek, C., D.G. Mann and H.M. Jahns. 1995. Algae: an introduction to phycology. Cambridge University Press, Cambridge. pp. 623. Womersley, H.B.S. 1984. The marine benthic flora of Southern Australia. Part I. Government Printer, South Australia. pp. 329. Wynne, M.J. 2002. The reinstatement of the name Ulva nematoidea Bory de Saint-Vincent (Chlorophyta) and the placement of Ulva costata (Howe) Hollenberg in its taxonomic synonymy. Cryptogam. Algol. 23: 5–12. Received 20 November, 2003; accepted 17 December, 2004