Researchers Discover Big, Invasive Australian Crayfish in Texas

This smaller redclaw was one of many specimens present in south Texas final month. TPWD / Fb

Researchers from the College of Texas Rio Grande Valley and the Texas Division of Parks and Wildlife just lately got here throughout an enormous species of crayfish in a pond close to Brownsville. The redclaw crayfish, which comes from Australia, has been in america for a while, however these are a number of the first to be documented within the wild in Texas. 

Between January and March of this 12 months, a crew of researchers at UT collected three of the crayfish from an condo advanced pond that connects to an area resaca close to Brownsville, which is positioned in South Texas close to the Mexican border. (A resaca is a small, remoted lake that outcomes from seasonal flooding.) Then, in July, aquatic biologists from TPWD collected three extra specimens from the identical location.

“We don’t know when these invasive crayfish had been first launched or how far they’ve unfold, however we do know they will have a unfavourable impact on native species and biodiversity,” TPWD aquatic biologist Dr. Archis Grub mentioned in a press release. 

These weren’t the primary Australian redclaws present in Texas both. In 2013, Seth Patterson found and recorded a feminine crayfish with just a few infants on iNaturalist and reported the encounter to TPWD. Patterson’s crayfish was additionally discovered within the Rio Grande Valley.

Australian redclaw crayfish are a lot bigger than their North American counterparts. The species can develop as giant as two kilos, which is roughly the burden of an average-sized Maine lobster. This dimension distinction is one purpose the species considerations native biologists. 

“Due to their bigger dimension, they will have a much bigger ecological imprint on habitat modification,” Grubh explains. “One good factor is these are usually not burrowers, so we’re not too involved they’re going to begin digging by means of the stream banks in a bigger method, however they’re undoubtedly identified to change the vegetation.” 

Along with their huge dimension, Australian redclaw crayfish are prolific reproducers, and wholesome females will drop hundreds of eggs per 12 months. At this price, the species can alter habitat, outcompete native crayfish species, and instantly feed on native fish communities. As soon as the crayfish set up their inhabitants, they’re almost unattainable to eradicate, in keeping with the Australian New South Wales Government. 

The species can also be identified to hold crayfish plague, a illness that has decimated crayfish populations in Europe and elsewhere. The illness is a priority for aquatic managers, however the dangers are at the moment unknown. 

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Redclaws are farmed in aquaculture operations worldwide, together with Belize, Indonesia, and China. There have been makes an attempt in america to lift the species in captivity, however most have failed. As we speak, Florida is among the solely states that enables the species to be farmed.

Texas officers think about the non-native crayfish an unique species and it’s unlawful to lift them for buy, sale, or launch within the state. Because of this, TPWD officers imagine the species was almost definitely launched by means of the aquatics commerce.

“Launch of aquarium life is sadly a key means by which invasive species reminiscent of these crayfish are launched,” TPWD senior scientist Monica McGarrity defined within the press launch. She added that well-meaning aquarium house owners typically assume they’re doing the precise factor by releasing their pets into the wild, however doing this normally ends in hurt to the ecosystem.

“Proper now, it’s simply making the general public conscious and getting some info so you possibly can put pins on the map to see how far the unfold is,” says Grubh. “Spreading the phrase about this invasive species and reporting sightings to TPWD will help us higher perceive the place it’s distributed so we will probably take steps to assist stop its unfold.”