The fish so rare we don’t know where it lives – for now

The clown wedgefish is a very cryptic species. So cryptic, in fact, that scientists don’t even know where it lives.

For decades, the only reason scientists knew the clown wedgefish (Rhynchobatus cooki) existed at all was its presence at markets in Singapore and Jakarta.

The fish disappeared off the map entirely in the early 21st century, only to be spotted again in pictures on social media in the late 2010s.

“It was such good news, after almost 20 years where there’s no record of this species. We thought it was possibly extinct, but it’s still there,” says Benaya Simeon, who is beginning a PhD on the wedgefish at Charles Darwin University.

Simeon is part of a team of Australian, Indonesian and US researchers who are hoping to figure out the habitat of the clown wedgefish, and how to conserve it.

The social media posts allowed the researchers to narrow the fish’s range to the southwest Riau Islands, in between Sumatra and Singapore.

Now, they’re using a combination of environmental DNA (eDNA) sampling, and working with local fishers, to learn more about the elusive creature.

“If we want to conduct any conservation management or fisheries management, of course, we will talk not only about the habitat, but also about the people,” says Simeon.

“I want to know what they know about the species, what they say about the species, and how they will support any conservation effort for the species. I want to dig out a local understanding about the species from the local people.”

A research team travelled to the island of Singkep in June to collect water samples, which are now being tested for traces of wedgefish DNA in the US.

“In these islands, the typical habitat is quite diverse: some of it is very rocky, some of it is very sandy, some of it is half seagrass and coral reef. So we want to understand the distribution where the species exists,” says Simeon.

“During our fieldwork we were able to collect 100 samples [of water] from 33 sites around the island,” says Associate Professor Nicole Phillips, from the University of Mississippi, US.

If any of these samples contain clown wedgefish DNA, that will give the researchers a much clearer sense of its habitat.

Simeon is also planning to tap into the social networks of the islands, to listen to local fishers. The research team includes local community members who are watching for the fish in markets.

“Fishers are a human resource who understand where these fishes exist, because they’ve fished every day for years,” says Simeon.

This will require local facilitators, since there are so many islands and communities where the fish could be.

“I can’t go one by one to each village […] so I need to make a good system to collect the data,” says Simeon.

Social media will also be helpful.

“The information from this species was collected from Facebook. So I thought besides making a social network to collect the data, I also need to use social media platforms which are commonly used by local people.”

With this combination of tactics, Simeon says she’s optimistic they’ll figure out the fish’s habitat. Then, the conservation effort can begin in earnest.

“Indonesia is a developing country, and very dependent on the fisheries – they’re socio-economically also very important for our people,” she says.

“So I think not only finding where the fish is, but how to promote the conservation and management effort for the species, will be important. That research and scientific baseline needs to be conducted in a robust way.”