List of cnidarians of Ireland

There are 302 species of cnidarians (phylum Cnidaria) recorded in Ireland.[1]

The cnidarians' distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Their bodies consist of mesoglea, a non-living jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell thick. They have two basic body forms: swimming medusae and sessile polyps, both of which are radially symmetrical with mouths surrounded by tentacles that bear cnidocytes. Both forms have a single orifice and body cavity that are used for digestion and respiration. Many cnidarian species produce colonies that are single organisms composed of medusa-like or polyp-like zooids, or both (hence they are trimorphic).[2][3][4]

Cnidarians found in Ireland and Irish waters include sea pens, sea anemones, hydroids, sea jellies ("jellyfish") and corals.

Order Actiniaria (sea anemones)

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Actinia fragacea (strawberry anemone)
 
Stomphia coccinea
 
Calliactis parasitica living on the shell of a common whelk, occupied by soldier crab.

Order Alcyonacea (soft corals)

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Alcyonium digitatum (dead man's fingers)
 
Eunicella verrucosa

Order Ceriantharia (tube-dwelling anemone)

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Arachnanthus sarsi, photographed off Rathlin Island
 
Pachycerianthus multiplicatus (firework anemone)

Order Pennatulacea (sea pens)

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Isozoanthus sulcatus in Lough Hyne

Order Anthoathecata (athecate hydroids)

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Bougainvillia muscus
 
Spanish shawl feeding on Eudendrium ramosum
 
Clava multicornis

Family Hydridae (hydras)

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Family Porpitidae (chondrophores)

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Velella velella colony
 
Tubularia indivisa (oaten pipes hydroid)

Order Leptomedusae (thecate hydroids)

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Craspedacusta sowerbii

Order Siphonophorae (siphonophores)

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Apolemia uvaria (string jellyfish)
  • Apolemia uvaria (string jellyfish, barbed wire jellyfish, long stringy stingy thingy)
 
Portuguese man-o'-war

Class Scyphozoa (true sea jellies)

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Rhizostoma pulmo

Order Semaeostomeae (flag-mouth sea jellies)

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Cyanea capillata (lion's mane jelly)

Order Scleractinia (stony corals, hard corals)

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Caryophyllia smithii
 
Zigzag coral

Order Stauromedusae (stalked jellies)

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References

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  1. ^ "Irish Biodiversity: a taxonomic inventory of fauna" (PDF). Retrieved 2023-08-21.
  2. ^ "Species Browser".
  3. ^ "Home" (PDF).
  4. ^ "Sea Anemones and Corals - OceanAddicts".
  5. ^ a b "Common Hydra (Hydra vulgaris) - Detail - Biodiversity Maps".
  6. ^ "Craspedacusta sowerbyi - Detail - Biodiversity Maps".
  7. ^ a b "Coral reefs in Irish Waters".
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