Vegetative and Sexual Reproduction of Bloom-forming Dinoflagellate Noctiluca Scintillans (Ehrenberg) McCartney from Tropical Cochin Estuary (Southwest coast of India): In-situ and Laboratory Studies

• Twinkle Sathish ^[1] ; Lathika Cicily Thomas ^[1] ; K. B. Padmakumar ^[1]
  1. [1] Cochin University of Science and Technology

     Cochin University of Science and Technology

     India

     
• Localización: Thalassas: An international journal of marine sciences, ISSN 0212-5919, Vol. 37, Nº. 1, 2021, págs. 31-37
• Idioma: inglés
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• Resumen

  • The lifecycle of red tide forming dinoflagellate Noctiluca scintillans (Ehrenberg) McCartney was investigated from the estuarine waters of Cochin and also from their clonal cultures. Reproductive divisions including asexual binary fission and sexual isogamete formation were studied. Certain vegetative cells were observed to undergo binary fission. Gametocyte mother cells underwent meiosis followed by several synchronous mitotic divisions which resulted in the production of 256–1024 mature spindle-shaped haploid isogametes attached on the surface of the gametocyte mother cell body. After several hours, gametes were observed to fuse and form diploid zygotes. The zygote underwent differentiation from spindle to spherical, with a reduction in the flagellar number and develops into a minuscule trophont. These trophonts later attained maturity as the cell size increased. The life cycle of Noctiluca scintillans thus appear to be a diplontic type. Hence, the study illustrates different life cycle stages of N. scintillans based on both in-situ and clonal culture studies. In-situ life cycle study is first of its kind in the reproductive biology of the species.