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Violet Sea Snail

Scientific name: Janthina janthina
Phylum Mollusca

Distribution: This floating snail is found in Queensland, New South Wales, Victoria, South Australia, Western Australia and eastern Tasmania. Widespread overseas in Atlantic, Pacific and Indian Oceans in tropical and subtropical waters.

Description: The Violet Snail is a pretty purple colour and is sometimes found washed ashore, along with other members of the “blue armada” being the Blue bottles, By the wind sailors and Glauca,the sea lizard.

Ecology: The Violet sea snail inhabits the ocean surface by secreting a raft of mucus bubbles to keep it afloat. It spends its whole life drifting on the ocean surface in warm seas at the mercy of the winds. It is blind and has a paper-thin shell. It feeds on by-the-wind sailors and other colonial hydroids that drift through the oceans. This gastropod molluscs grows up to 4 cm.. It manages to float by producing its own mucus-covered bubble raft, and feeding on floating cnidarians such as Blue Bottles (Physalia physalis) and By-the-wind Sailors (Velella velella).

Violet snails are protandric hermaphrodites, meaning they are born male and develop into females over time. Fertilization is internal, but males lack a penis, so there is no direct mating. Instead, the males release their sperm into a case that drifts to a female, where the sperm fertilizes the eggs.The Violet Snail broods its young and releases the miniature adults directly into the sea.The tiny purple snails are immediately able to build their own rafts. They use their foot to agitate the water, creating bubbles, which they bind together with mucus. If the bubble raft ever breaks apart, the snail will sink into the ocean and die.

Interesting facts: The head of the violet snail has a long cylindrical snout . They have no eyes. The flesh of this species is deep violet or black and in adults the operculum is absent.

Mucus trail from a Violet Sea Snail
Photo by odonatah from Flickr


Status: Janithina janthina is the commonest member of the Janthinidae family.There appears to be increasing numbers washed up by the winds which may be related to many areas experience in increasing winds and a change in the dominant wind direction. Generally they are in plentiful numbers in the open ocean habitat.


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