The botanical magazine = Shokubutsu-gaku-zasshi

, 105:589

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

  • Hideo Ohba
  • Hiroaki Nashima
  • Sachito Enomoto
Article

DOI: 10.1007/BF02489433

Cite this article as:
Ohba, H., Nashima, H. & Enomoto, S. Bot Mag Tokyo (1992) 105: 589. doi:10.1007/BF02489433

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.laetevirensCaulerpa racemosa var.peltataChlorophyceaeDevelopmentMorphological VariationReproduction

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