The Red Claw Crayfish with a Reproductive Rate of 1,000 Eggs at a Time Recently Discovered in Texas Raises Concerns Among Experts.
Scientists from the University of Texas Rio Grande Valley have collected several specimens of Red Claw Crayfish (Cherax quadricarinatus) in the Brownsville area this year, according to a statement from the Texas Parks and Wildlife Department (TPWD) on August 12. In January and February of this year, the research team discovered three specimens in a complex pond connected to a nearby horseshoe lake located in Cameron County. Following this discovery, aquatic biologist Archis Grubh examined several locations in the region last July and found three more Red Claw Crayfish.
A Red Claw Crayfish captured in Texas. (Photo: TPWD)
Previously, the Red Claw Crayfish had only been recorded once in Texas. In 2013, an individual reported to the public biodiversity database iNaturalist of the California Academy of Sciences and the National Geographic Society after spotting a female Red Claw Crayfish and three juveniles in Brownsville. The only other location where this species has been found in the wild in the U.S. is California. However, experts believe they have the potential to spread and harm native ecosystems.
“We do not know when this invasive crayfish species was first introduced or how far they have spread. But we know they negatively impact local species,” Grubh stated.
The Red Claw Crayfish is native to many areas in northern Australia and Papua New Guinea, according to the Great Lakes Nonindigenous Aquatic Species Information System (GLANSIS). They prefer stagnant waters such as horseshoe lakes or still ponds, slow-flowing environments with rocks and burrows. They can also thrive in rivers, lakes, and estuaries with fast-moving water.
This species is a large crayfish that features a combination of green-blue and reddish-brown coloration. Mature males have distinctive red patches on their claws. They can grow to about 25 cm in length and weigh up to 0.9 kg. The Red Claw Crayfish has a high reproductive rate, with females laying up to 1,000 eggs at a time and reproducing five times a year. Additionally, they grow very quickly, potentially reaching full size in less than a year.
With a high adaptability to various environments and a diverse diet, the Red Claw Crayfish has the potential to become a successful invasive species worldwide. Once a population of Red Claw Crayfish is established, eradication becomes nearly impossible.
Both male and female Red Claw Crayfish have been recently captured in Texas, indicating that they are reproducing within the state. Experts are concerned they will negatively impact the local ecosystem by competing with native crayfish, preying on fish, and altering natural habitats. They also carry various viruses, bacteria, fungi, and parasites that can be transmitted to local crayfish.
