Hundreds of invasive aquarium fish removed from San Marcos River

Suckermouth armored catfish removed from San Marcos, San Antonio rivers

Plecostomus (Hypostomus plecostomus) and the vermiculated sailfin catfish (Pterygoplichthys disjunctivus) are both commonly referred to as armored catfish. (San Antonio River Authority)

SAN MARCOS, Texas – A total of 406 invasive suckermouth armored catfish were removed from the San Marcos River in recent weeks.

Texas Rivers and Streams, a division of Texas Parks and Wildlife, posted a photo on Facebook Thursday stating that the fish were removed during a dewatering event at Rio Vista Park.

The fish “have been introduced to numerous water bodies in Texas through aquarium dumping — Never Dump Your Tank!” officials said.

“Dumping anything out of an aquarium — fish, animals, and plants — can have devastating consequences for Texas’ natural waterbodies,” according to “This is true for both freshwater and saltwater aquariums. Never dump them into a natural body of water or flush them down the toilet.”

The San Antonio River Authority (SARA) released a similar public service announcement last November saying aquarium fish are considered an invasive species.

More specifically, SARA officials said armored catfish burrow into riverbanks, which leads to erosion of the banks and eventually bank collapse.

Texas Parks and Wildlife officials echoed that sentiment in a Facebook post shared Tuesday saying “suckermouth armored catfish, aka ‘plecos,’ compete with native fishes and dig burrows in banks, leading to erosion and bank destabilization.”

An aquarium fish that was released into the wild has grown out of control. Suckermouth armored catfish, aka “plecos,”...

Posted by Texas Parks and Wildlife on Tuesday, January 18, 2022

In December researchers from Texas A&M and Texas State universities fitted some of the armored catfish with experimental tags to study their movements in an effort to help make the removal of the species from local rivers more effective.

Returning fish to pet stores or trying to rehome them are the two options pet owners should consider, according to SARA.

Related: People are dumping aquarium pets into San Antonio River and it could cause bank collapse

About the Author:

Mary Claire Patton has been a journalist with KSAT 12 since 2015. She has reported on several high-profile stories during her career at KSAT and specializes in trending news and things to do around Texas and San Antonio.