Spring Cavefish - Ecology

Ecology

Spring cavefish stay underground after dawn, but then emerge into surface waters at dusk. They are dark brown dorsally and fade to a creamy brown towards the pelvis and reach a maximum length of three and a half inches (90 mm). The head is sloped, and it has a protruding lower jaw. The fish has no pelvic fin or adipose fin. Their dorsal fin is set further back. This species is susceptible to developing retinoblastomas.

The spring cavefish is well adapted to its environment, as it has a well-developed sensory system. This system occurs in clusters on the head. Most fish detect food by sight, taste, touch, or smell, or by a combination of these senses. Sight is important in the detection of food by most species, but this is presumably excluded with the slightly blind spring cavefish. They use their underdeveloped eyes to distinguish between light and darkness. However, spring cavefish cannot readily distinguish between edible and non-edible substances by touch alone, but once in contact with the lips, the sense of taste enables the fish to distinguish among these items.

Another hurdle for this species is that food is often lacking in their habitats, so they compensate for this scarcity of food with cannibalistic behavior. Cannibalism in the spring cavefish presumably serves two purposes: it enables the adults to survive in an environment where food is the principal limiting factor, and it serves as a means of population control. The spring cavefish can be considered its own predator, because of the cannibalism behavior and the lack of natural predators within the caves. However, they are also known to eat a wide range of insects, small crustaceans, smaller fish, and some detritus.

Cave environments are known to provide a relatively stable habitat in terms of temperature fluctuations. However, the different species living in caves are reliant on food being brought to them by underground streams. This makes spring cavefish highly vulnerable to external factors as subterranean aquifers are becoming increasingly tapped for irrigation purposes, and many sites may be at risk from drying out either temporarily or permanently ).