12 August 2022

There are invasive crayfish in South Texas and I have nothing to do with it

Australian red-clawed crayfish, Cherax quadricarinatus
Yesterday, Texas Parks and Wildlife released a press release about Australian red-clawed crayfish (Cherax quadricaratus) in South Texas.

What is kind of weird is that it the press release mentions “Researchers from the University of Texas Rio Grande Valley” (UTRGV) but didn’t say which researchers or even which department.

This morning, I get emails from people thinking I was involved, because I was the only crayfish researcher at UTRGV for a long time. Never mind that I haven’t worked there for while. I don’t know who from UTRGV had a hand in this.

Dan Johnson, who knows Texas crayfish better than I do, says that this is not a new discovery. He stated that red-clawed crayfish were found in one pond nine years ago. (I am a little annoyed that I was around at the time and nobody saw fit to mention this to me. I could think of a bunch of ways I could have used that information.) 

Edit: This might be a reference to this record of red-claws on iNaturalist.

They have now spread to one more location a few mile away. That’s... not much of an invasion?

Red-clawed crayfish were imported into Mexico years ago for aquaculture and the food market. They escaped, because crayfish are good at that, and now they are very widespread in Mexico. I don’t think there is any interest in trying to contain them in Mexico. One researcher joked, “They’ve been given their Mexican passports.”

Worth noting that there were people in Texas aquaculturing redclawed crayfish. But either spread from Mexico or release of pets seems the most likely source of these crayfish. That one of the ponds is right next to an apartment building suggests aquarium dumping to me .

External links

Invasive Australian Redclaw Crayfish Present in Texas

Photo from here.

No comments: