Elusive bigfin squid have been seen and filmed in Australian waters for the first time. They were spotted by researchers in the Great Australian Bight on two separate scientific expeditions.

Bigfin squid (Magnapinna) can measure as long as 7m because of their trailing arms and tentacles, and live in deep ocean waters, so there have been relatively few sightings worldwide.

The two voyages were carried out by Australia’s national science research agency, the Commonwealth Scientific & Industrial Research Organisation (CSIRO), aboard its vessel Investigator. The sightings took place in 2015 and 2017, but the scientific study has only recently been published in Plos One.

On the first expedition underwater cameras were towed at depths between 946 and 3258m, resulting in two sightings, and ROV-mounted cameras were used two years later, capturing images of three more squid.

Although the expeditions were wide-ranging the five squid were recorded in one comparatively small area, but the scientists were able to confirm them as distinct individuals by their markings and colour.

Precise dimensions were obtained for the first time by projecting laser beams onto the squid. One of them was 1.8m long, with its body making up only about 15cm of that length.

At the start of November Divernet reported on the discovery on Australia’s Great Barrier Reef of another bizarre deepwater squid species but one that had never been recorded live before – a ram’s horn squid (Spirula spirula).