[Photo: Texas State University at San Marcos]

Toothless Blindcat
Trogloganis pattersoni

Description: The toothless blindcat, of the family Ictaluridae, is 1 of 2 cave-dwelling (troglobotic) catfish in North America. The toothless blindcat is the only member of the Trogloganis genus, distinguished from other Ictalurids by its many cave-adapted features. They can grow up to 4.1 inches (10.4 cm) long, with a weight of 0.6 ounces (16 grams). This catfish has large nostrils, a small, red toothless mouth with thin lips, well-developed barbels, and a snout which overhangs its mouth. This catfish has many cave-adapted features. These include its lack of eyes, pale white or pinkish body, a well-developed lateral line, and lack of an air bladder. The absence of an air bladder, which is present in most fish, gives the toothless blindcat the ability withstand the immense pressure in the deep caves it inhabits. This bladder has been replaced by an abundance of fatty tissue which gives it buoyancy.

Life History: The toothless blindcat does not have any external distinguishable sex characteristics. Females have frequent egg production and are mature when they reach greater than 2.4 inches (6 cm) in length. This catfish is herbivorous, utilizing a well developed olfactory system to find food, as well as utilizing vibrations detected by its lateral line. These fish feed on the detritus in mud which is consumed by sucking up mud on the bottom of its habitat.

Habitat: The toothless blindcat lives in the subterranean waters of Edwards Aquifer at depths of 1000-1900 feet (305-582 m) and temperatures of 80 degrees F (27 deg C). This fish lives in habitats under great hydrostatic pressure.

Distribution: Trogloganis pattersoni is restricted to the San Antonio Pool of Edwards Aquifer in Bexar County, TX (256,000 acres [103,600 ha]). The fish has been collected at five artesian wells in the Southern part of Bexar County.

The map below depicts the area where this species has been reported (according to literature review).

Reported Species Distribution of the Toothless Blindcat (Trogloganis pattersoni) [Figure: Houston Advanced Research Center]

Status: The toothless blindcat is a state listed threatened species. The population is abundant within its range; although due to their deep cave habitat, observations of the toothless blindcat can be difficult. This population is sensitive because its range is very small and a drop in groundwater could pose a risk to this species.

Resources:

Edwards Aquifer Research and Data Center, Toothless Blindcat Status

Texas State University at San Marcos, Biology Department, Texas Freshwater Fishes, Toothless Blindcat Species Profile