#4879 · 🪼 jellyfish, starfish, worms & co
Sea Walnut
🇳🇱 Amerikaanse Ribkwal ·Mnemiopsis leidyi
9 photos from iNaturalist (Creative Commons) · credits & licences
- 1. © Vidar@aqua-photos · CC BY-NC-SA 4.0
- 2. © Rita Jansen · CC BY-NC-SA 4.0
- 3. © Sylvain Le Bris · CC BY-NC 4.0
- 4. © theSigmaArts · CC BY-NC 4.0
- 5. © Kent McFarland · CC BY-NC 4.0
- 6. © JaguarGozandoSelva · CC BY-NC 4.0
- 7. © Mike G. Rutherford · CC BY-NC 4.0
- 8. © Klaus Kevin Kristensen · CC BY 4.0
- 9. © Rita Jansen · CC BY-NC-SA 4.0
what is it?
Mnemiopsis leidyi , the warty comb jelly or sea walnut , is a species of tentaculate ctenophore (comb jelly), originally native to the western Atlantic coastal waters. Three species have been named in the genus Mnemiopsis , but they are now believed to be different ecological forms of a single species M. leidyi by most zoologists.
base stats
Bars compare against all animals on log scales: up to 300,000 Dutch and 600,000 worldwide sightings (the most-seen species), 150 t (blue whale), 30 m and 400 years (Greenland shark).
fun facts
- Spotted 41 times in the Netherlands on iNaturalist: the #33 most seen of the jellyfish, starfish, worms & co in NL.
- 3,538 observations worldwide on iNaturalist.
- Scientifically named by Alexander Emanuel Agassiz in 1865 (161 years ago).
- Not originally Dutch: it was introduced to the Netherlands.
fact sheet
- English
- Sea Walnut
- Nederlands
- Amerikaanse Ribkwal
- scientific name
- Mnemiopsis leidyi
- class
- Tentaculata
- order
- Lobata
- family
- Bolinopsidae
- in NL
- introduced
- sightings in NL
- 41
- sightings in Europe
- 807
- sightings worldwide
- 3,538
- GBIF records in NL
- 11,563
- weight
- —
- length
- —
- lifespan
- —
- named
- 1865 by Alexander Emanuel Agassiz
Sources: iNaturalist taxon 180788, Wikidata Q133630, GBIF 2501248, Wikipedia (EN), Wikipedia (NL). Intro text from Wikipedia (CC BY-SA 4.0).Updated 2026-10-24.