Cnidaria: Anemones, Jellyfish, Hydrocorals, Corals, Zoanthids
Cnida...what? Pronounced "nI-dar-ee-uh", this group of invertebrates is characterized by tentacles laden with stinging cells. In fact, this is where they get their peculiar name. "Knidos" in Greek means "nettle". Each tentacle is armed with thousands of miniature harpoons all coiled up within a cell. When a creature brushes the Cnidarian's trigger, the harpoon uncoils and it's barbs stick quite well into the flesh of the unwary prey. How can you identify a cnidarian underwater? Cnidarians have radial symmetry (draw a line down their center and you have two equal halves). Their tentacles form a ring around the only opening of their body. They take on two forms - either a polyp shape like corals and anemones, or a medusa shape like jellyfish.
Cnida...what? Pronounced "nI-dar-ee-uh", this group of invertebrates is characterized by tentacles laden with stinging cells. In fact, this is where they get their peculiar name. "Knidos" in Greek means "nettle". Each tentacle is armed with thousands of miniature harpoons all coiled up within a cell. When a creature brushes the Cnidarian's trigger, the harpoon uncoils and it's barbs stick quite well into the flesh of the unwary prey. How can you identify a cnidarian underwater? Cnidarians have radial symmetry (draw a line down their center and you have two equal halves). Their tentacles form a ring around the only opening of their body. They take on two forms - either a polyp shape like corals and anemones, or a medusa shape like jellyfish.
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| Anemones | |
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Buried anemone (Urticina coriacera) |
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Burrowing anemone (Anthopleura artemisia) |
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Columbia sand anemone (Urticina Columbiana) |
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Fish-eating anemone (Urticina piscivora) |
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Painted anemone (Urticina crassicorus) |
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Pink-tipped anemone (Anthopleura elegantissima) |
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Short plumose anemone (Metridium senile) |
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Giant plumose anemone (Metridium farcimen) |
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Strawberry anemone (Corynactis californica) |
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Swimming anemone (Stomphia didemon) |
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Ten tentacled burrowing anemone (Halcampa decemtentaculata) |
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Tube-dwelling anemone (Pachycerianthus fimbriatus) |
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White-spotted anemone (Urticina lofotensis) |
| Jellyfish | |
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Tiny red sausage jelly (Euphysa spp.) |
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Fried egg jelly (Phacellophora camtschatica) |
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Sea nettle (Chrysaora fuscescens) |
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Unknown jelly (gelitinatus indeterminatus) |
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Windowed stalk jelly (Manania handi) |
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Moon jelly (Aurelia labiata) |
| Sea pens | |
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Orange sea pen (Ptilosarcus gurneyi) |
| Zoanthids | |
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Orange zoanthid (Epizoanthus scotinus) |