The bloody-belly comb jelly, Lampocteis cruentiventer, is a deep-water ctenophore with a red stomach and shimmering comb rows. Its appearance under lights is striking, but the red color helps conceal it in its dark natural habitat.
Where it lives
MBARI’s species account records this animal in North Pacific midwater, from Canada to Baja California and off Japan, at approximately 250–1,500 meters (820–4,900 feet). It reaches about 16 cm, or roughly 6 inches.
MBARI’s references identify the formal species description as a 2001 publication by Harbison, Matsumoto and Robison. Calling it “discovered 20 years ago” or assigning a 2003 discovery date makes a permanent article misleading.
Why a red stomach helps it hide
Very little red light reaches these depths. Red tissue therefore appears dark rather than bright crimson under natural deep-water conditions. A pigmented stomach can also conceal light from swallowed bioluminescent prey.
The detailed diet remains incompletely known; MBARI lists it as unknown. That uncertainty should not be replaced with a precise menu inferred from another comb-jelly species.
The rainbow shimmer is not bioluminescence
The Monterey Bay Aquarium account distinguishes this animal’s iridescence from biological light production. Incoming light interacts with its moving cilia, creating the traveling rainbow effect seen in illuminated footage. The bloody-belly is not itself bioluminescent.
The comb rows also propel the animal. Ctenophores belong to a different phylum from cnidarian jellyfish; the shared “jelly” name does not make their feeding structures or life cycles identical.
Studying a fragile deep-water animal
Remotely operated vehicles allow researchers to observe these animals in their habitat. Monterey Bay Aquarium also reports that years of husbandry work, including reducing oxygen to reflect the species’ preferred environment, helped extend its survival in managed care.
This is specialized institutional work, not a recipe for a home aquarium. Exact display settings should not be copied into a general jellyfish care guide or attributed solely to water pressure.
For a contrasting light-producing animal, read about the crystal jelly and GFP. Our jellyfish feeding overview explains cnidarian feeding, which should be kept distinct from assumptions about this ctenophore.
