A new invasive species has surfaced in Texas: the Australian redclaw crayfish. Native to northern Australia and Papua New Guinea, this freshwater crustacean has been spotted in the Rio Grande Valley, nearly 8,000 miles from home. Environmental officials are concerned, and of course we need to know if this invader is friend or foe.
So how did this crayfish get here? The first U.S. sighting occurred in 2013 in Los Angeles, recorded on the website iNaturalist. Nearly a decade later, a second was found in a Texas apartment complex pond in 2022. That discovery led researchers to find three more nearby.
Now scientists, including Texas Parks and Wildlife Aquatic Biologist Dr. Archis Grubh, are investigating its spread in Southern Texas. Each female can lay up to 5,000 eggs annually, though officials haven’t yet confirmed widespread breeding. To track their movement, researchers have set traps with hot dogs—a snack the critters seem to love—around Brownsville.
How the species arrived remains unclear, but experts suspect "aquarium dumping"—owners releasing unwanted pets into the wild. Texas Parks and Wildlife’s senior scientist Monica McGarrity warned that such releases can introduce invasive species that threaten native ecosystems.
Is it dangerous? While not dangerous to humans, redclaw crayfish pose a threat to local wildlife. Growing up to two pounds within a year, they can outcompete native species for food and habitat. They may also carry a parasite known as crayfish plague, which could harm native crayfish populations.
Typically bottom dwellers, redclaws hide under rocks and debris, making them difficult to spot. However, their rapid reproduction and adaptability make them a potential ecological threat.
If you want to prevent their spread, you can eat them. Redclaw crayfish are farmed for consumption in Australia and resemble large crawfish, growing up to 10 inches long. However, there probably aren’t enough in Texas to make them a reliable source for dinner.
If you spot one, Texas Parks and Wildlife urges you to report it by emailing a photo and location to aquaticinvasives@tpwd.texas.gov.