Green Jelly Ball
Ophrydium versatile
The Green Jelly Ball is a single-celled, colony-forming ciliate found in clean freshwater lakes and ponds. Individual trumpet-shaped cells reside within a shared gelatinous matrix that can grow to the size of a human fist. They derive their characteristic green color from endosymbiotic Zoochlorellae (algae) which provide the ciliate with products of photosynthesis. The colonies are typically attached to submerged substrates such as stones or aquatic plants.
Details
Identification
Green, gelatinous, elastic spheres; microscopically visible individual cells in loricae; trumpet-shaped body of individuals when extended.
Social behavior
Lives in highly organized colonies with a shared gelatinous envelope.
Diet
Mixotrophic: Filters bacteria and detritus from the water and additionally utilizes photosynthetic products from symbiotic algae.
Hunting strategy
Generation of a water current via an apical ring of cilia for filtration.
Overwintering
Formation of resting stages (cysts) in the sediment.
Ecology
Ecological role
Important component of the microbial loop; links bacterial biomass to higher trophic levels.
Natural predators
Gastropoda (snails), aquatic insect larvae, various zooplankters.
Competitor species
Other sessile Peritricha and benthic algae for settlement space.
Ecosystem service
Water clarification through filtration of bacteria; oxygen release through photosynthesis.
Threats
Eutrophication (nutrient input), herbicide use, destruction of littoral habitats.
Scientific profile
Profile
Habitat
Freshwater; prefers oligotrophic to mesotrophic lentic waters (lakes, ponds) or slow-moving streams; usually attached to substrates such as macrophytes, wood, or stones in the littoral zone.
Reproduction
Asexual reproduction by longitudinal binary fission; sexual reproduction via conjugation (exchange of micronuclei).
Ecological role
Important component of the microbial loop; functions as both primary producer and consumer; the gelatinous colonies provide habitat for other microorganisms.