Off the east coast of the island of Tasmania, Australia, a very unusual fish is found — a fish that uses its fins not to swim but to push itself along the seafloor, almost like walking on its hands. And that, along with its color, gives it its name — red handfish.

Other than being quite unusual among fish, the red handfish (Thymichthys politus) is also very rare. It was thought till recently only 20-40 individuals survived in a single population off southeast Tasmania. But following a tip-off from someone who claimed to have seen a red handfish in a different area, researchers discovered another population with another 20-40 individuals.

Given the rarity of the creature, the new site where the fish was found is not being publicly disclosed till such time as authorities have decided a management mechanism. But it is several kilometers away from the other site — Frederick Henry Bay, also in southeast Tasmania — with a red handfish population. The two populations are definitely distinct because the range of the red handfish is limited to about the size of two tennis courts, given the way it moves.

Red Handfish Red handfish seen off the coast of Tasmania, Australia. Photo: Antonia Cooper

After receiving a tip-off, a team of seven divers from the Institute for Marine & Antarctic Studies (IMAS), at University of Tasmania in Hobart, spent two days looking for the fish, and were on the verge of giving up when Antonia Cooper, a technical officer at IMAS, spotted one.

“We were diving for approximately three and a half hours and at about the two hour mark we were all looking at each other thinking this is not looking promising. 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. Finding a new population that is definitely distinct from the existing one is very exciting.  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,” Cooper said in a statement Tuesday.

Eight individuals were identified from the area, leading researchers to conclude the population could actually be between 20 and 40 individuals. That effectively doubles the estimate of how many red handfish remain in total in the world.

IMAS scientist Rick Stuart-Smith said in the statement: “Finding this second population is a huge relief as it effectively doubles how many we think are left on the planet. 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.”

While the International Union for Conservation of Nature (IUCN) doesn’t have a listing for red handfish, it is listed as critically endangered by the Australian government. There are some other species of handfish in the region which are also extremely rare. For instance, there is the spotted handfish, which is critically endangered according the IUCN Red List of Threatened Species.

Even with an increased estimated population of between 40 and 80 individuals, the red handfish is still pretty rare, and could well be the world’s rarest fish, like the researchers said in the statement. It is possibly rarer than Deils Hole pupfish, which is found only in one location in Death Valley National Park, Nevada, and is often referred to as the rarest fish in the world. It is also listed as critically endangered in the IUCN Red List, with 63 individuals during a count in fall 2013.