100

Alabama Cavefish

North America

100

Speoplatyrhinus poulsoni

Endangered

Slow and complex reproductive cycle
Changes in groundwater quality and level
Competition with other cavefish species

The Alabama Cavefish which can only be found in underground pools in the north-western part of the state is considered as one of the rarest cavefish species in North America. It is classified as a troglobite creature, which means completely well-adapted to living in a subterranean environment and possessing highly-developed senses in order to survive in total darkness.

Discovered in 1967 by biologist John E. Cooper, this cave-dwelling freshwater fish does not have eyes. Instead, it has an elongated flattened head and translucent but spiky-looking fins. Its diet consists of bat guano, crustaceans, insects, and other water organisms.

According to scientists, the Alabama Cavefish is suspected to have the slowest reproductive rate among all cavefish species. Its breeding cycle is also highly reliant on the amount of flooding the caves receive as well as the nutrients in the water. Whatever food resources are available, the Alabama Cavefish has to compete with other cavefish species which makes it difficult to grow in number.

Continued and drastic variations in flooding patterns and seasonal weather affect the groundwater quality and level. It is expected to reproduce at least once a year but it seems that it only does so during seasonal flooding. Without flooding, there would be no positive hormonal response from the Alabama Cavefish and no juvenile fish produced. And because there is less and less amount of bat guano that is its vital food source, it also affects its health and lifespan in general. Moreover, the pollution level and chemical contamination that can be found in the water also compromises the existence of an already declining population.