Largest Organisms - Animals - Invertebrates - Cnidarians (Cnidaria)

Cnidarians (Cnidaria)

The Lion's mane jellyfish (Cyanea capillata) is the largest cnidaria species, of the class Scyphozoa. The largest known specimen of this giant, found washed up on the shore of Massachusetts Bay in 1870, had a bell diameter of 2.5 m (8 ft), a weight of 150 kg (330 lb). The tentacles of this specimens were as long as 37 m (121 ft) and were projected to have a tentacular spread of about 75 m (246 ft) making it one of the longest extant animals.

• Corals and sea-anemones (Anthozoa)

The largest individual species are the sea-anemones of the genus Discoma, which can attain a mouth disc diameter of 60 cm (2 ft). Longer, but much less massive overall, are the anemones of the genus Ceriantharia, at up to 2 m (6.6 ft) tall. Communities of coral can be truly massive, a single colony of the Porites genus can be over 10 m (33 ft), but the actual individual organisms are quite small.

• Box jellyfish (Cubozoa)

The largest of the box jellyfish is the species Chironex fleckeri of the Australasian and South Pacific oceans, which can attain a mass of 6 kg (13 lb), a 30 cm (1 ft) bell and a tentacle length up to 2 m (6.6 ft). This species is also the most common and dangerous box jelly.

• Hydrozoans (Hydrozoa)

The colonial siphonophore Praya dubia can attain lengths of 40–50 m :(130–160 ft). The Portuguese man o' war's (Physalia physalis) tentacles can attain a length of up to 50 m (170 ft).