The red handfish is a funny little critter that uses its fins to scuttle along the rocky seafloor. Dwelling exclusively in the waters off Tasmania, it is also one of the rarest fish in the world. So researchers were excited to find an entirely new population of red handfish hiding amidst Tasmania’s reefs. As Calla Wahlquist reports for the Guardian, the discovery may double the number of known red handfish.
Previously, scientists were aware of only one red handfish population of between 20 and 40 individuals, which swim along a stretch of reef in the Frederick Henry Bay. But a member of the public recently reported seeing a little handfish in a nearby area. So seven divers from the University of Tasmania’s Institute for Marine and Antarctic Studies and the citizen science project Reef Life Survey set out to try and find these elusive marine creatures.
After spending about two hours under water without any success, the team was nearly ready to call off the search. “My dive partner went to tell the other divers that we were going to start heading in and I was half-heartedly flicking algae around when, lo and behold, I found a red handfish,” IMAS Technical Officer Antonia Cooper says in a statement.
In total, the divers spotted eight individuals, but they suspect that the new site is also home to between 20 and 40 red handfish. “Finding this second population is a huge relief as it effectively doubles how many we think are left on the planet,” IMAS scientist Rick Stuart-Smith explains in the statement.
There are 14 known species of handfish endemic to the waters off the coast of Tasmania, several of which are endangered. As Elaina Zachos of National Geographic explains, these little fish are particularly vulnerable because they have a low reproduction rate—and when they do breed, they lay their eggs on pieces of seaweed, which tend to get knocked around by swimmers and boats. People also keep handfish as pets, which leads to poaching.
The Australian government has instituted a recovery plan for four species of handfish, and a captive breeding program for the spotted handfish was launched in September. Researchers held back on breeding red handfish, however, because they feared their populations were too small to withstand the removal of a few individuals. But now that a new group has been found, scientists are once again investigating the viability of a breeding program for these peculiar creatures.
Scientists are also heartened by the fact that the new population of red handfish is likely genetically isolated from the other known group. Handfish are small—they typically grow between two and five inches—and are not strong swimmers, so they don’t tend to wander very far.
“Finding a new population that is definitely distinct from the existing one is very exciting,” Cooper says. “It means there’s potentially a bigger gene pool and also that there are potentially other populations out there that we’re yet to find, so it’s very exciting indeed.”