The Alabama cavefish (Speoplatyrhinus poulsoni) is a critically endangered species of amblyopsid cavefish found only in underground pools in Key Cave, located in northwestern Alabama, United States in the Key Cave National Wildlife Refuge.

[6] It was discovered underneath a colony of gray bats in 1967 by researchers Robert A. Kuehne and John E. Cooper[7] and scientifically described in 1974.

However, researchers agree that the flooding of the cave triggers a hormonal change in the cavefish, prompting the fish to begin the reproductive cycle.

[13] Annual rainfall and flooding in the cave produce changes in water level, temperature, and food availability for the fish.

[9] The Alabama cavefish is roughly 7.2 cm (2.8 in) in length and has no eyes or discernible pigmentation, appearing semitransparent with a slight pink hue.

[6] It has an elaborate system of sensory papillae arranged in ridges on the head and sides, an adaptation to the dark environment of the cave.

[7] The Alabama cavefish, like most fish, utilizes seasonal cues to trigger hormonal changes that lead to its growth and reproduction.

[9][10] This flooding results in an increased inflow of water into the cave and a small temperature change, signaling to the cavefish to begin reproduction.

[12] In 2019, amendments to the recovery plan were made that changed the criteria for down-listing and created a criterion for delisting.

[1] The species was last assessed in April 2012, and although its population trend is stable, it is still listed as critically endangered.

[7] This makes it unlawful to import, export, transport, sell, receive, acquire, or purchase (alive or dead, including parts, products, eggs, or offspring) the Alabama cavefish.

[7] Secondly, The Tennessee Valley Authority, which owns the two entrances to the caves, has installed a fence to limit human disturbance.

[14] The largest human-induced threat to the survival of the Alabama cavefish is groundwater contamination within the recharge area of Key Cave.

[10] Furthermore, the collection of the species by amateurs or for scientific purposes poses a major threat due to the already small population size.

[7] All of these factors, combined with the already small population size and limited home range, pose severe threats to the Alabama cavefish.