WhenToDive
Invertebrate · 🐙

Blue-Ringed Octopus

Hapalochlaena species

Blue-rings are tiny (palm-sized) octopuses with one of the most potent venoms in the ocean — tetrodotoxin, the same neurotoxin found in pufferfish. They are not aggressive and bites on divers are essentially unheard of, but the animal is famous enough that spotting one is a bucket-list sighting for many macro divers. The characteristic blue rings only appear when the animal is alarmed; at rest it is beige or brown. Lembeh, Anilao, and parts of southern Australia are the main destinations. Never touch or provoke one for a better photograph.

Blue-rings are tiny (palm-sized) octopuses with one of the most potent venoms in the ocean — tetrodotoxin, the same neurotoxin found in pufferfish. They are not aggressive and bites on divers are essentially unheard of, but the animal is famous enough that spotting one is a bucket-list sighting for many macro divers. The characteristic blue rings only appear when the animal is alarmed; at rest it is beige or brown. Lembeh, Anilao, and parts of southern Australia are the main destinations. Never touch or provoke one for a better photograph.

The year at a glance

Global aggregated reliability — at any given month, how reliably can you find this species somewhere in the world?

Score 1–5 · global aggregated reliability Rare Moderate Reliable

Where to see them in April

Sorted by April reliability and species status.

  1. 01

    Lembeh Strait

    Indonesia · southeast asia · peak
    4/5

Full season breakdown

Peak Present Rare

Destination
J
F
M
A
M
J
J
A
S
O
N
D
Notes
Lembeh Strait
Regular sightings with experienced guides
Malapascua
Rare / occasional