The Northern Cavefish, scientifically known as Amblyopsis spelaca, resides exclusively in limestone caves in Indiana and Mammoth Cave in Kentucky, USA. Due to their challenging environment, they have adapted to consume a wide variety of food sources to survive. This blind fish spends its entire life in darkness and is well-adapted to the absence of sunlight.
It’s not that they lack eyes; rather, their tiny eyes are covered by a layer of skin. However, they possess over a hundred “fingers”: the head and entire body of this cave fish are covered with small, protruding fleshy spots that resemble tiny fingers. These “fingers” enable them to sense vibrations in the water. With just this simple adaptation, they can capture prey and swim effortlessly in the pitch-black water.
Another fascinating aspect is that cave fish incubate their eggs in their mouths: After the female lays eggs and they are fertilized, she swallows the eggs into her mouth. The eggs are retained in the gill chamber, where they are nurtured for two months until they hatch.
The blind cavefish has a slender, small body with a single dorsal fin. Its mouth is large, and the lower jaw protrudes slightly, with a slightly yellowish hue.
Amblyopsis spelaca thrives in freshwater, with adult males reaching an approximate length of 10.4 cm.
