HELPING HANDS

These bizarre, shy fish that walk instead of swim face a precarious future in the waters of southern Australia.

- AMANDA FREEMAN

THERE WAS GREAT excitement on board CSIRO’s RV Investigator. “I found you a handfish,” Dr Candice Untiedt told Carlie Devine as they scanned images of the sea floor captured by the ship’s deep-sea camera. Carlie, a research technician, and Candice, a marine ecologist, both with CSIRO, were working on the Investigator when Candice spotted the strange fish. “I was sitting right next to her,” Carlie says. “It was so exciting because I’d said, ‘We’ve got to find one’, and there it was, just sitting on the bottom.”

Sitting on the bottom is what handfish do. Unlike most fish, they don’t have a swim bladder to regulate their buoyancy and so don’t often swim, although they can dart short distances. Instead, these fish walk along the sea floor, using their hand-shaped fins to move about and eating small crustaceans, worms and molluscs as they go.

While obviously a handfish, the identity of the species Candice and Carlie saw remains a mystery. It looked most like a narrowbody handfish, collected only twice in scientific trawls, in 1984 and 1996. But it was bigger. “The narrowbody specimens are both about 5.5cm long, whereas the one we found was probably more than 10cm,” Carlie explains. “We don’t know how big the narrowbody species gets, so we don’t actually have a lot of information to go on.” It could even be a new species.