Invasive critters were collected from a Texas apartment complex pond earlier this year — and wildlife experts say the females can lay up to 1,000 eggs at a time.
University of Texas Rio Grande Valley researchers first collected three Australian redclaw crayfish in January and February, according to an Aug. 11 news release from the Texas Parks & Wildlife Department. They were found in a pond that connects to a Brownsville-area resaca, a type of oxbow lake.
This was only the second place the species, also discovered in California, has been found in the U.S.
Experts say a female crayfish and several of its young were spotted at this same location and identified on iNaturalist in 2013, “indicating this species has been present at this location for some time.”
As a Texas aquatic biologist began surveying the area in July, he found three more Australian redclaw crayfish between the pond and the resaca about two miles away.
“We don’t know when these invasive crayfish were first introduced or how far they have spread, but we do know they can have a negative effect on local species and biodiversity,” Dr. Archis Grubh said in the news release. “Spreading the word about this invasive species and reporting sightings to TPWD can help us better understand where it is distributed and potentially take steps to help prevent its spread.”
The species can be identified by their “large size, large left claws with a red patch on the outer edge and the presence of four distinct ridges on the top of the head.” Officials say they prefer slow-moving streams and stagnant water, and they can move between bodies of water.
Because officials found both males and females, there’s concern for reproduction in the area. Females brood up to five times a year with 1,000 eggs per clutch.
“Australian Redclaw Crayfish grow rapidly and can reach maximum size, up to two pounds, in under a year,” officials said. ”These large crayfish can significantly alter habitat and vegetation, competitively exclude native crayfish, and impact native fish communities by direct predation. Australian Redclaw Crayfish can also carry Crayfish Plague as well as other parasites/diseases that could impact native crayfish.”
It is illegal to buy, sell, own or release Australian redclaw crayfish in Texas.
If you see one, you are asked to email photos and location information to firstname.lastname@example.org.
Brownsville, in southern Texas, is right across the Mexico border and along the western Gulf Coast.