Caption

Blue ringed octopus (Hapalochlaena lunulata). This small octopus inhabits the tropical waters of the Indo-Pacific region. It is highly poisonous, paralysing its prey using poison in its saliva. The poison is tetrodotoxin (TTX), one of the most toxic chemicals known, which is also found in puffer fish. TTX is produced by symbiotic bacteria which inhabit the salivary glands of this octopus. A bite can be fatal to a human within an hour. The octopus uses the poison to paralyse its prey and as a form of defence. It mainly eats small fish and crustaceans. It reaches a length of around 15 centimetres. Photographed in Mabul, Malaysia.