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Culture studies onCaulerpa (caulerpales, chlorophyceae) III. Reproduction, development and morphological variation of laboratory-culturedC. racemosa var.peltata

  • Hideo Ohba
  • Hiroaki Nashima
  • Sachito Enomoto
Article

Abstract

Reproduction, development and morphological variation of the marine green algaCaulerpa racemosa var.peltata from the southern part of Japan were studied in culture in the laboratory. Anisogamous biflagellate male and female gametes were produced monoeciously and copulated with each other. Settled zygotes became spherical and increased in volume. After five weeks, they formed two germ tubes which extended in opposite directions. Both germ tubes became elongated and branched, resulting in the formation of creeping, filamentous, protonema-like plants. These plants formed primary shoots which differentiated into creeping rhizomes and upright axes. Each upright axis successively formed ramuli and developed into an assimilator. The morphology of assimilators, i.e., shape and arrangement of ramuli, varied with culture coditions. The effects of temperature and light intensity on the formation of assimilators were investigated with 25 combinations of 5 temperatures (20.0–30.0C) and 5 light intensities (0.5–8.0 klux). The morphological plasticity of this alga is identical to that ofCaulerpa racemosa var.laetevirens, which was previously described by the present authors. Thus, apparently, the plasticity of this taxon is correlated with environmental factors. It appears, moreover, thatC. racemosa var.peltata andC. racemosa var.laetevirens are ecophenes (ecads) of a single species.

Key words

Caulerpa racemosa var.laetevirens Caulerpa racemosa var.peltata Chlorophyceae Development Morphological Variation Reproduction 

References

  1. Børgesen, F. 1907. An ecological and systematic account of the Caulerpas of the Danish West Indies. Kgl. Danske Vidensk. Selsk. Skrifter, Ser. 7,4: 337–392.Google Scholar
  2. —. 1925. Marine algae from the Canary Islands. I. Chlorophyceae. Kgl. Danske Vidensk. Selsk., Biol. Medd.5(3): 1–123.Google Scholar
  3. Calvert, H.E. 1976. Culture studies on some Florida species ofCaulerpa: morphological responses to reduced illumination. Br. Phycol. J.11: 203–214.Google Scholar
  4. Egerod, L. 1975. Marine algae of the Andaman Sea coast of Thailand: Chlorophyceae. Bot. Mar.18: 41–66.CrossRefGoogle Scholar
  5. Enomoto, S. andH. Ohba. 1987. Culture studies onCaulerpa (Caulerpales, Chlorophyceae) I. Reproduction and development ofC. racemosa var.laetevirens. Jpn. J. Phycol.35: 167–177.Google Scholar
  6. Eubank, L.L. 1946. Hawaiian representatives of the genusCaulerpa. Univ. Calif. Publ. Bot.18: 409–432.Google Scholar
  7. Gilbert, W.J. 1942. Notes onCaulerpa from Java and the Philippines. Pap. Mich. Acad. Sci., Arts & Letters27: 7–26.Google Scholar
  8. Kajimura, M. 1976. On swarmer production inCaulerpa peltata var.peltata from the Oki Islands, Shimane Prefecture. Bull. Jpn. Soc. Phycol.24: 25–28 (in Japanese with English abstract).Google Scholar
  9. Lüning, K. 1981. Light.In C.S. Lobban and M.J. Wynne, ed., The Biology of Seaweeds, pp. 326–355. Blackwell Sci. Publ.Google Scholar
  10. McLachilan, J. 1973. Growth media-marine.In J.R. Stein, ed., Handbook of Phycological Methods: Culture Methods and Growth Measurements, pp. 25–51. Cambridge Univ. Press, Cambridge.Google Scholar
  11. Ohba, H. andY. Aruga. 1982. Seaweeds from Ishigaki Island and adjacent islets in Yaeyama Islands, southern Japan. Jpn. J. Phycol.30: 325–331 (in Japanese with English abstract).Google Scholar
  12. — andS. Enomoto. 1987. Culture studies onCaulerpa (Caulerpales, Chlorophyceae) II. Morphological variation ofC. racemosa var.laetevirens under various culture conditions. Jpn. J. Phycol.35: 178–188.Google Scholar
  13. Okamura, K. 1930. On the algae from the Island Hatidyo. Rec. Oceanogr. Wk. Japan2: 92–110, pls. 6–10.Google Scholar
  14. — 1936. Nihon kaisô-shi (Algae of Japan). Uchida Rokakuho, Tokyo (in Japanese).Google Scholar
  15. Peterson, R.D. 1972. Effects of light intensity on the morphology and productivity ofCaulerpa racemosa (Forsskal) J. Agardh. Micronesica8: 63–86.Google Scholar
  16. Tandy, G. 1934. Experimental taxonomy in marine algae, with special reference toCaulerpa. Proc. Linn. Soc. London146: 63–64.Google Scholar
  17. Taylor, W.R. 1928. The marine algae of Florida with special reference to the Dry Tortugas. Carnegie Inst. Wash. Publ. No. 379: 1–219, pls. 1–37.Google Scholar
  18. — 1950. Plants of Bikini and other northern Marshall Islands. Univ. Michigan Press, Ann Arbor.Google Scholar
  19. — 1960. Marine Algae of the Eastern Tropical and Subtropical Coasts of the Americas. Univ. Michigan Press, Ann Arbor.Google Scholar
  20. Weber-van Bosse, A. 1898. Monographie des Caulerpes. Ann. Jardin Bot. Buitenzorg15: 243–401, pls. 20–34.Google Scholar
  21. Yamada, Y. andT. Tanaka. 1938. The marine algae from the Island of Yonakuni. Sci. Pap. Inst. Algol. Res., Fac. Sci., Hokkaido Imp. Univ.2: 55–86.Google Scholar

Copyright information

© The Botanical Society of Japan 1992

Authors and Affiliations

  • Hideo Ohba
    • 1
  • Hiroaki Nashima
    • 2
  • Sachito Enomoto
    • 2
  1. 1.Department of Aquatic BiosciencesTokyo University of FisheriesTokyoJapan
  2. 2.Marine Biological Station, Faculty of ScienceKobe UniversityHyogo-kenJapan

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