419 Dive Log Australasia AUGUST 2026

A mating pair of Southern Blue-ringed Octopuses.

appear. Males use a specialised arm to transfer sperm to the female, but the process is not random or simple. Research suggests females may mate with more than one male, and males adjust their mating effort depending on the situation. This matters because both sexes have limited reproductive output. The female produces a single clutch, often around 50 large eggs, and the male has

a limited number of sperm packets. In an animal that breeds only once, every mating opportunity matters. There is also evidence that these octopuses can recognise sex and mating history through touch and chemical cues. It shows a small animal making fast, specialised decisions using sensory information we barely understand.

The mating chase got a bit chaotic. At one point, these Southern Blue-ringed Octo puses nearly ran over a Southern Velvetfish (Aploactisoma milesii) resting motionless on the bottom. They missed its face by only a centimetre or two .

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Dive Log Australasia #419 August‘26

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