Renilla reniformis
ORDER
Pennatulacea
FAMILY
Renillidae
TAXONOMY
Pennatula reniformis Pallas, 1766, "Mare Americum."
OTHER COMMON NAMES
English: Atlantic coral.
PHYSICAL CHARACTERISTICS
Colonial; a large primary polyp up to 3 in (7.5 cm) long and wide has a heart-shaped frond arising from a fleshy stalk. Smaller polyps are embedded in the upper surface of the frond: typical octocoral feeding polyps and tiny nonfeeding polyps lacking tentacles. Primary polyp appears purple because of colored sclerites in its tissue. The smaller embedded polyps are transparent.
DISTRIBUTION
Western Atlantic from North Carolina, United States, south to Tierra del Fuego, Argentina.
HABITAT
Stalk anchored in sand with frond lying flat on the surface, from low intertidal to shallow subtidal zones.
BEHAVIOR
Produces bioluminescent bright green waves of light that run across the surface of the colony when disturbed at night. Small tentacle-less polyps act as water pumps, allowing colony to quickly deflate to half its normal size or expand.
FEEDING ECOLOGY AND DIET
Polyps secrete a sticky net of mucus that can trap small zooplankton.
REPRODUCTIVE BIOLOGY
Nothing is known.
CONSERVATION STATUS
Not listed by IUCN.
SIGNIFICANCE TO HUMANS
Bioluminescence is created by a protein called "Green Fluorescent Protein" (GFP). The GFP gene has been isolated and is sold commercially for use in molecular biological studies of gene expression in mammals. Scientists have isolated from the sea pansy unique diterpene lipids known as renillafoulins that prevent fouling organisms (e.g., barnacles) from settling on boats and other manufactured marine structures without killing them.
