Fish of the Day
Today's fish of the day is the Alabama Cavefish!
The Alabama Cavefish, scientific name Speoplatyrhinus poulsoni, is known for being one of the rarest troglobitic fish species in North America. Discovered in 1967, by the time the alabama cavefish was scientifically described in 1974, there were only about 100 fish left. On any visit to the cave, only about 10 fish have ever been seen, but they are consistently different fish, so the estimated number is a little under 100, making them critically endangered. This also makes them a possibility for the rarest cavefish in North America!
Despite the large waterways connecting caves in Key Cave National park to several other cave systems, the Alabama cavefish has restricted itself to only one cave for reasons we don't understand. A search of over 120 caves in the surrounding area revealed no populations or signs of populations. With a range consisting only of Key cave in Lauderdale county, Alabama; these fish are constantly faced by the threat of extinction, and most of their worries are based on the limited home range, and waters entering the cave. Any water with chemicals, especially fertilizers and other agricultural runoff are a large concern. That along with competition from more aggressive cavefish, and predation from nearby crawfish. Due to their living situation and delicate population, much is unknown about these fish. But, let us go over what we do know!
The diet of the Alabama cavefish consists mostly of invertebrates found in the caves: copepods, isopods, smaller cavefish, spiders, beetles, and anything else it can find that will fit in its mouth. They grow up to a size of 2-3 inches in length. They have no eyes or pigment, and hunt solely based off of sensory protrusions that dot the head and sides, a trait evolved to handle the almost complete darkness. These fish have no breeding season, and instead breed based off of the environmental signal: when the caves flood in the winter and spring. Insufficient flooding can lead to years where no breeding or spawning occurs, and when it does females carry few eggs, and even fewer eggs hatch. Their lifespans, based off of the lifespan of Northern cavefish, are an estimated 5-10 years.
