Divers have discovered a new population of what is considered to be one of the world’s rarest fish.
Until recently, scientists knew of only one tiny population of about 20 to 40 red handfish (Thymichthys politus), an unusual species that prefers to “walk” on the seafloor using its hand-shaped fins over swimming, from a strip of rocky reef in Frederick Henry Bay in southeast Tasmania.
But last month, seven divers from the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS) and the citizen science project Reef Life Survey counted eight more red handfish in a small area measuring 50 by 20 meters (164 by 66 feet) several kilometers away from Frederick Henry Bay. The team estimates that this new site, currently undisclosed, harbors about 20 to 40 individuals, doubling the number of known red handfish on Earth, according to a press release from the IMAS.
Antonia Cooper, technical officer at the IMAS, had spent more than two hours diving with her team and was about to turn back when she spotted the first red handfish.
“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,” Cooper said in the statement.
“Finding a new population that is definitely distinct from the existing one is very exciting,” she added. “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.”
Video courtesy of University of Tasmania/Reef Life Survey.
The new population is also helping scientists understand the rare fish better.
“We’ve already learned a lot from finding this second population because their habitat isn’t identical to that of the first population, so we can take some heart from knowing red handfish are not as critically dependent on that particular set of local conditions,” said Rick Stuart-Smith, a scientist at the IMAS.
The red handfish is one of three critically endangered species of handfish found in Tasmania. While the spotted handfish (Brachionichthys hirsutus) can still be seen in the waters off Hobart, the capital of Tasmania, the Ziebell’s handfish (Brachiopsilus ziebelli) is feared extinct.
“Ziebell’s handfish hasn’t been seen in over a decade, and there is a feeling that it’s quite possibly extinct, or at least very close to being so,” Stuart-Smith said.