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Invasive Australian Redclaw Crayfish found in Rio Grande Valley

Posted at 12:04 PM, Aug 12, 2022
and last updated 2022-08-12 14:16:17-04

University of Texas Rio Grande Valley researchers recently found the first known evidence of an invasive crayfish species in Texas.

Earlier this year, according to a press release from Texas Parks and Wildlife, three Australian Redclaw Crayfish specimens were collected at an apartment complex pond that connects to a nearby resaca, or channel, in the Brownsville area.

California is the only other place the species has been found in the United States.

Texas Parks and Wildlife Department (TPWD) Aquatic Biologist Archis Grubh looked in several other sites in the Rio Grande Valley during July and found three more Australian Redclaw Crayfish between the apartment pond and a nearby channel 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,” said Grubh. “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.”

Male and female Australian Redclaw Crayfish were found, so reproduction is a concern.

The species can reproduce quickly, with females breeding up to five times a year. They can lay 1,000 eggs per reproduction.

Australian Redclaw Crayfish grow very fast and can get as big as 2 less than a year. They can alter their habitat significantly and out-compete native crayfish for food.

All members of the crayfish family Parastacidae are considered exotic species in Texas and cannot be legally purchased, sold, or possessed in aquariums. Releasing these crayfish also are illegal in public waters.

"Release of aquarium life is, unfortunately, a key means by which invasive species such as these crayfish are introduced,” said TPWD Senior Scientist for Aquatic Invasive Species Monica McGarrity.. “Well-meaning, uninformed aquarium owners sometimes release their pets thinking they’re doing the best thing for them, but if they do survive, they can become invasive and harm the native aquatic species and ecosystem. Aquarium owners should research alternatives to aquarium dumping and help prevent introductions of the next invasive species.”

Australian Redclaw Crayfish sightings should be reported to TPWD by emailing photos and location information to