Invertebrate
Japanese Sea Nettle
Chrysaora pacificaJapanese sea nettles drift through the coastal waters of the Northwest Pacific, using pulsing bells and long trailing tentacles to ensnare passing plankton and small fish. Their striking reddish-brown radial stripes make them conspicuous marine floaters and popular subjects in public aquariums. During seasonal blooms, large aggregations can exert significant predatory pressure on local planktonic ecosystems.
MarineVenomousInvertebrate
—observations
—countries
—peak records
Not EvaluatedConservation statusIUCN Red List categoriesLCNTVUENCREWEXNot Evaluated — not placed on the risk ladderRed List categories, explained →
Diet & preyZooplankton, Comb Jellies, Small Fish
Predators
- Ocean Sunfish
- Leatherback Sea Turtle
- Large Pelagic Fish
ThreatsMarine pollution, coastal development, severe ocean temperature shifts
HabitatsCoastal ocean waters, bays, and open seas
Life span1–2 years
Classification
- OrderSemaeostomeae
- FamilyPelagiidae
- GenusChrysaora
- SpeciesChrysaora pacifica
Range data is not available yet.
Interaction riskVery high
- Low
- Moderate
- High
- Very high
- Why interaction risk is very high
- Delivers a painful sting; maintain a safe distance in the water and on beaches.
- Why it is dangerous
- Nematocysts on trailing tentacles inject toxins causing burning pain, rash, and localized tissue inflammation.
- How to recognize a risky encounter
- Features a translucent bell with distinct dark orange-brown radiating bands and trailing fine tentacles.
- What to do
- Keep clear when swimming in coastal bays and avoid handling washed-up specimens.
Responsible observation
- Maintain Distance: Observe pulsing medusae from a boat or pier without reaching into trailing tentacles.
- Wear Protective Gear: Wear a full rash guard or wetsuit when swimming in waters during seasonal blooms.
Co-occurring Species (c) A H, some rights reserved (CC BY), uploaded by A H · cc-by
Close Relative (c) Ed Bierman, some rights reserved (CC BY) · cc-by
Close Relative (c) Erin McKittrick, some rights reserved (CC BY), uploaded by Erin McKittrick · cc-by
Close Relative (c) John Hepburn, some rights reserved (CC BY), uploaded by John Hepburn · cc-by
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