A New Crayfish Species Was Hiding in Plain Sight Among Common Aquarium Pets, Researchers Find

Scientists have described a new species of colorful crayfish—and it might already be sitting in your aquarium. The researchers detailed their discovery in the journal Zootaxa last week.

Though crayfish—also called crawdads or crawfish—may not be everyone’s idea of the perfect animal companion, scientists in the Czech Republic found the newly named Cherax pulverulentus in a shipment of Indonesian pet crayfish they’d purchased for their lab in March 2023.

The lobster-like crustacean is a burrowing freshwater crayfish endemic to the Indonesian part of New Guinea, according to the study. Specimens have large eyes and claws, as well as smooth bodies. The species comes in two color forms: Blue form crayfish are a dark hue with orange joints and tails, while purple form crayfish are turquoise with purple spots and white along their joints and tails.

“Like the other members of this genus, this crayfish is aggressive, strictly freshwater (inhabiting streams and maybe also lake ecosystem), probably moderately burrowing, omnivorous and gonochorist,” meaning it has distinct male and female individuals, Jiří Patoka, a zoologist at the Czech University of Life Sciences Prague and a co-author of the study, tells Popular Science’s Laura Baisas. They grow more than four inches long and might live between five and ten years.

Despite the fact that Cherax pulverulentus has been sold as an aquarium pet for more than two decades in places including Europe, Japan, Indonesia and the United States, it was never differentiated from similar species. It was referred to as “Hoa Creek,” “Irian Jaya” or “Blue Moon” crayfish, names that were also used for other types of crayfish, according to the study.

The new formal name, Cherax pulverulentus, means dusty crayfish in Latin, in homage to the crustacean’s dotted exoskeleton.

This recent find coincides with another crayfish discovery: Two other species were newly described in North Carolina this month. Like the “dusty” aquarium crayfish, they had been mistakenly lumped together with another species, as Frank Graff reports for PBS North Carolina.

“Taxonomy is essential for conservation,” Bronwyn Williams, a research curator at the North Carolina Museum of Natural Sciences, tells PBS. “If a unique creature does not have a formal name, it is not eligible for the resources needed to manage and protect it.”

The New Guinea crayfish discovery has also been tied to conservation. It “highlights the need for better management and identification in the aquatic pet trade as well as recognition and protection for the creatures in their natural habitat,” writes Micah Hanks for the Debrief.

To confirm their finding, the researchers conducted morphological and genetic analyses of six specimens. Broadly, however, not much is known about the species, since it has been mostly observed in captivity. One exception is a blue form specimen discovered in a Hungarian thermal spring, which the researchers suspect was previously a pet, dumped there by its former owner.

They now aim to study the newly identified species in its natural environment.

“Crayfish are just one group of awesome animals native to New Guinea, the island facing many environmental risks. In this regard, we believe that our findings will help to highlight the importance of this island from a biodiversity perspective, and more conservation activities will apply there,” Patoka tells Popular Science. “Last but not least, I would like to alert aquarium owners: Do not release your pets outdoors!”

Margherita Bassi | READ MORE

Margherita Bassi is a freelance journalist and trilingual storyteller. Her work has appeared in publications including BBC Travel, Discover magazine, Live Science, Atlas Obscura and Hidden Compass.