Imagine a tiny fish with hands for fins, a grumpy downturned mouth, and a flamboyant mohawk. That’s the red handfish (Thymichthys politus) for you. This unique anglerfish, found only in two small patches of reef off the coast of Tasmania, Australia, grows no bigger than 4 inches long and comes in a range of reds, browns, and pinks, often with brighter colors around its fins. Individual red handfish can be distinguished by their unique markings.
Unlike many fish, this odd creature, which lives on the seabed, lacks a swim bladder for buoyancy. Instead, its pectoral fins have evolved into large “hands” that it uses to walk across the seafloor. “It’s an amazing curiosity of evolution,” Andrew Trotter, leader of the red handfish conservation breeding project at the University of Tasmania’s Institute for Marine and Antarctic Studies (IMAS), told Live Science in an email. “While walking with fins is rare, some fish can even do this on land. The loss of a swim bladder is a common trait among many benthic fish, as fine-tuned buoyancy control is no longer needed.”
Despite their unusual appearance, researchers find red handfish quite endearing. “Of course, you would have to say they are a bit cute,” Trotter said. This critically endangered fish is highly vulnerable to threats such as habitat loss, pollution, and urban development. Because they can’t move very far on their hand-like fins, they are particularly susceptible to these threats. “The red handfish is probably in the rarest ‘handful’ of fish in the world, no pun intended,” Trotter said. “It’s really hard to know exact numbers, but it has to be right up there with the most imperiled fish species that we know of.”
Their rarity led researchers in Australia to take 25 of the 100 known wild individuals into captivity for several months, fearing that marine heatwaves could wipe out the entire species. Trotter, who cared for the captive fish, observed that some individuals had distinct personalities. “One might call this ‘attitude’,” he said. While caring for these endangered animals was “wonderful, but also very stressful at times,” Trotter noted, three died in captivity. However, 18 were returned to the wild once the heatwaves subsided. The remaining four are now in IMAS’ captive breeding program to help protect the species’ future.
But their chances of survival are still uncertain. “When you have so few animals left in one place, it seems likely an extreme event could lead to extinction,” Trotter said.
