A new species of freshwater crayfish with a vividly violet shell and brilliantly blue claws has been discovered in Indonesia. Though new to science, the colorful crustacean has been very popular in the ornamental fish trade in Europe, North America, and Asia for about a decade already. 

Several years ago, independent researcher Christian Lukhaup of Hinterweidenthal, Germany, came across a photo of the gorgeous crayfish taken by a friend in New Guinea, The Washington Post reports. He then started seeing them in pet stores, but the dealers didn’t know for sure where they came from—or they weren’t willing to share their secret with potential competitors. "It is like an investigation in a crime case," Lukhaup tells New Scientist. "This is the only way to find out more." 

With some sleuthing, he learned that the critter comes from the clear waters of Hoa Creek near the village Teminabuan in the southern-central part of the Kepala Burung Peninsula of West Papua, Indonesia. Based on the shape of the body and the chelae (or claws), as well as the coloration of a dozen specimens from the wild and from aquariums, Lukhaup described the crawdad as a new species in the genus Cherax. 

"I think it's one of the most beautiful crayfish," Lukhaup tells The Post. "It's very striking." In fact its name, Cherax pulcher, comes from the Latin “pulcher” for beautiful. The new species was described in ZooKeys last week. 

Cherax pulcher comes in at least two different color forms: a white, blue, and violet morph and a greenish-gray morph. Both have blue and white chelae. The male specimens are between 83 to 96 millimeters (3.3 to 3.8 inches) long, and the slightly shorter females range between 83 and 90 millimeters (3.3 to 3.5 inches). To the right, you can see an immature male (top) from Hoa Creek and a female greenish-gray morph (below) from Maju Aquarium in Jakarta. 

You might remember the two striking new species of vampire crabs described earlier this year. One has purple claws, the other has orange nippers, and they both have an intense yellow stare that gives them their vampiric appearance. Lukhaup was an author on that paper as well. Prior to being named new species, the two had also been popular in the aquarium trade for years.

Images: C. Lukhaup, ZooKeys (2015)