, Volume 398, Issue 0, pp 247-252

First online:

Preliminary observations on the development of kelp gametophytes endophytic in red algae

  • David J. GarbaryAffiliated withDepartment of Biology, St. Francis Xavier University, Antigonish
  • , Kwang Young KimAffiliated withFaculty of Earth Systems and Environmental Science, Institute of Marine Sciences, Chonnam National University
  • , AFF3>Terrie KlingerAffiliated withFriday Harbor Laboratories, University of Washington
  • , David DugginsAffiliated withFriday Harbor Laboratories, University of Washington

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The development of kelp gametophytes is described from field collections from the San Juan Islands, Washington from November, 1997 to March 1998. All gametophytes were endophytic in the cell walls of red algae, especially species with filamentous or polysiphonous construction. Gametophyte density ranged from a few to many hundreds of distinct individuals per host plant. Gametophytes formed extensive vegetative growths of irregularly branching filaments, mostly parallel to the host surface, consisting of up to 50 or more cells. Antheridia were formed at/or just above the surface of the host thallus. The stalked egg apparatus was perpendicular to the host surface. Following presumed fertilization, the zygotes developed with typical kelp embryology to form small epiphytic blades. The specific identity of the gametophytes is unknown, although the host plants were collected from three sites where the dominant kelp species were: a) Agarum fimbriatum, b) Nereocystis luetkeana and c) Alaria marginata, Costaria costata and Laminaria groenlandica.

Agarum endophytism gametophytes Laminariales Phaeophyceae Pleonosporium reproduction symbiosis