Invasive crayfish threatens Texas, causing many experts to worry

Scientists from the University of Texas Rio Grande Valley obtained several specimens of the red crayfish (Cherax quadricarinatus) in the Brownsville area this year, according to an August 12 announcement by the Parks and Wildlife Service. Texas (TPWD). During January and February of this year, the team discovered three specimens in a complex pond connected to the nearby horseshoe lake, located in Cameron County. Following the discovery, aquatic biologist Archis Grubh checked several sites in the area in July and found three more crayfish.

A crayfish caught in Texas.

Before that, red crayfish had only been recorded once in the state of Texas. In 2013, an individual notified the public biodiversity database iNaturalist of the California Academy of Sciences and the National Geographic Society after seeing a female and three juvenile crayfish in Brownsville. The only other place where this species is found in the wild in the US is California. However, experts believe they have the ability to spread and harm native ecosystems.

"We don't know when this invasive crayfish species was first introduced or how far they have spread. But we do know they have a negative effect on local species," Grubh said.

The crayfish is native to the environment in many parts of northern Australia and Papua New Guinea, according to the Great Lakes Non-Indigenous Aquatic Species Information System (GLANSIS). They prefer stagnant water such as horseshoe lakes or still ponds, slow currents, rocky environments and burrows. They can also live in rivers, lakes, fast-flowing lagoons.

This is a large crayfish with a green - blue color combined with red - dark brown. Adult males have a characteristic red patch on the claws. They can reach a length of about 25 cm and weigh 0.9 kg. Red crayfish has a high reproductive rate, female shrimp lay eggs up to 1,000 eggs / time and 5 times a year. In addition, they grow very quickly, reaching their maximum size in less than a year.

Together with their high adaptability to a wide range of environments and diverse food consumption, the red crayfish has the potential to become a successful invasive species around the world. Once populations of red crayfish have formed, eradicating them is nearly impossible.

Both male and female crayfish were caught recently in Texas, meaning they are breeding in the state. Experts fear they will negatively affect local ecosystems as they compete with native crayfish, eat fish and alter the natural environment. They also carry many viruses, bacteria, fungi and parasites that can be transmitted to crayfish locally.