RECOGNITION OF SYMBIOTIC ALGAE BYHYDRA VIRIDIS.A QUANTITATIVE STUDY OF THE UPTAKE OF LIVING ALGAE BY APOSYMBIOTICH. VIRIDIS

作者：Rosevelt L. Pardy, LEONARD MUSCATINE · 发表于：Biological Bulletin · 年份：1973 · DOI：10.2307/1540637 · 被引用次数：73 · 研究领域：Marine Invertebrate Physiology and Ecology、Cephalopods and Marine Biology、Planarian Biology and Electrostimulation

1. An individual Hydra viridis (Florida Strain) harbors approximately 1.5 x 105 unicellular green algae. These algae are normally found in the basal portion of gastrodermal digestive cells. An average of approximately 18 algae per digestive cell is encountered in the central region (stomach and budding zone) of the hydra under a given set of maintenance conditions.2. The average number of algae per digestive cell may range from 7 to 22 depending on feeding schedules and photoperiod under which hydra cultures are maintained.3. The symbiosis can be synthesized artifically by injecting symbiotic algae from H. viridis into the coelenteron of aposymbiotic H. viridis. Within 15 minutes after injection the algae are taken up by the digestive cells, apparently by phagocytosis. During the next hour, the algae move from the site of uptake to the basal part of the digestive cell.4. Both green and aposymbiotic H. viridis can take up only about 8 ± 2 algae from an injected suspension of cells. Uptake may be limited by the extent to which the cell can sustain phagocytosis, rather than by availability of intracellular space. In aposymbiotic H. viridis, the full complement of 18 algae is attained by algal cell division and requires about 18 days.5. An assortment of free-living and symbiotic algae were injected into H. viridis aposymbionts. All were rejected immediately with the exception of hydra algae and a symbiotic alga from Paramecium (NC64A) which formed a stable hereditary endosymbiosi...