Robsonella huttoni

The club pygmy octopus, *Robsonella huttoni*, is found in the waters of New Zealand and Australia. It was first formally described in 1943 by zoologist William Benham, who named it after Frederick Hutton, a prominent New Zealand naturalist. Adults display reddish, orangish, and greenish colouration and can grow to a length of 240 millimetres. The species is widespread across New Zealand, but in Australia it is restricted to southern regions. Its habitat includes tidal and subtidal reefs, reaching depths of 386 metres. The octopus’s distribution along the shore seems to shift with age, a pattern known as an ontogenetic niche shift. Unlike many octopus species, it has a paralarvae stage that lasts between 40 and 70 days. While records show individuals living up to 250 days, they likely survive longer. Information on conservation needs is scarce, though climate change may affect their range.

In terms of taxonomy, Benham, then a professor emeritus at Otago University, originally classified it as *Octopus huttoni* based on specimens from New Zealand’s Otago region. The specific name honours Frederick Hutton, who had earlier described New Zealand’s first octopus species, *Macroctopus maorum*. The species was most recently redescribed in 1999 by marine biologist Steve O’Shea. Its common name is the club pygmy octopus.

Phylogenetic work in 2020, using genetic data from cytochrome oxidase I, cytochrome oxidase III, and 16s rRNA, moved the species into the genus *Robsonella*. Researchers pointed to skin texture and radula morphology as supporting this placement. They also suggested the species likely evolved after the Antarctic Circumpolar Current formed during the Cenozoic era.

Adults reach up to 240 millimetres in total length, with especially large individuals recorded from Fiordland and smaller ones from southern Australia. The mantle is about 57 millimetres long. Living animals vary in colour, appearing reddish, orangish, or greenish. The head is well developed and covered in small, rounded papillae, with one or two hair-like appendages above each eye called occular cirri. The arms are also papillose. In adults, the tenth to thirteenth suckers are noticeably enlarged. The male’s third arm is hectocotylised, modified for storing and transferring spermatophores, and bears 69 to 74 suckers.