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Came across this Blue-Ringed Octopus late in the afternoon when they are most likely coming out to hunt/feed. The pictures above shows it catching a crab (Pic#1) as its tentacles envelopes the crab giving the roundish and bulky look. Pics#2 & #3 were taken as it swam away, carrying the crab. When they are swimming, their body colour tends to change to yellowish/brown compared to whitish/grey as in Pic#1. The greater blue-ringed octopus is despite its vernacular name a small octopus whose size does not exceed 10 centimeters, arms included, for an average weight of 80 grams. Its common name comes from the relatively large size of its blue ring (7 to 8 millimeters in diameter), so they are indeed larger than those of the other members of the genus and help to distinguish them. The head is slightly flattened dorsoventrally and finished in a tip. Its height arms are short. The coloration of this octopus varies with the circumstances and the ambient environment from yellow ocher to light brown through whitish (when inactive). The blue rings are about 60, spread throughout the entire animal's coat. The rings are roughly circular and are based on a darker blotch than the background color of the coat. A black line, whose thickness can vary to increase the contrast and be more visible, borders the electric blue circles. The blue rings are an aposematic adornment whose purpose is to clearly show to all potential predators that this octopus is highly venomous.
The greater blue-ringed octopus is widespread throughout the tropical and subtropical waters of the Indo-West Pacific from Sri Lanka to the Philippines and from Australia to south Japan. The greater blue-ringed octopus likes shallow waters with mixed seabed (rubble, reefs, sandy areas ...). Like all octopuses, it lives in a burrow and only comes out to search for food or a mate. The entrance of the shelter is littered with legs from meals (empty shells and crab shell and legs) and it's quite easily identifiable.
Spotted on Jan 11, 2016
Submitted on Jan 20, 2016
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