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The widemouth blindcat (Satan eurystomus) is a species of North American freshwater catfish endemic to Texas in the United States. It is the only representative of the genus Satan.

Widemouth Blindcat
Conservation status
Vulnerable  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Siluriformes
Family:	Ictaluridae
Genus:	Satan C. L. Hubbs & R. M. Bailey, 1947
Species:	S. eurystomus
Binomial name
Satan eurystomus C. L. Hubbs & R. M. Bailey, 1947

The widemouth blindcat's closest relative is the much larger flathead catfish, Pylodictis olivaris.[2]

It was first discovered inhabiting a well, and is adapted for a lightless underground environment. This species is distributed in five artesian wells penetrating the San Antonio Pool of the Edwards Aquifer in and near San Antonio, Texas.[3] These fish have been found with crustacean exoskeletons in their stomachs, and may be the top carnivore in their habitat.[2]

Like other cavefish, the widemouth blindcat lacks pigmentation and has no externally visible eyes. The eye remnants are extremely reduced in size with very little or no trace of a retina or lens; the optic tract is present, but always regresses before reaching the brain. The swim bladder in these fish is reduced, and the skull is mostly cartilaginous and not well-ossified, unlike the adults of most larger ictalurids. The lateral line is fragmentary and never reaches past the anterior part of the anal fin. This species also has a few paedomorphic traits (indicated by small size, kidney morphology, and weak ossification of the skeleton).[2] This species grows to about 13.7 cm (5.4 in) TL.[3]

The widemouth blindcat is a vulnerable species, and is threatened by groundwater pollution.[3]

See also

• Blindness in animals

References

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