Mexican Blind Cave Fish
Meet astyanax mexicanus also known as the mexican blind cavefish or blind cave tetra.
Mexican blind cave fish. The male is smaller and slimmer than the female. These fish are unique within the expansive tetra family and come in two distinct forms. 100 l 22 imp gal 26 us gal.
6 5 to 8 hardness. They can reach up to. But what about a species of fish that has evolved and adapted to having no eyes at all.
A larger tetra blind cave tetras need a minimum of 20 gallons for a school of 5. 3 4 the type species of its genus it is native to the nearctic realm originating in the lower rio grande and the neueces and pecos rivers in texas as well as the central and eastern parts of mexico. The blind cave tetra lives in deep caves in the wild.
It is a natural occurrence of genetic chance. And scientifically the fish is named as astyanax fasciatus mexicanus the most unusual thing about this fish is that the fry is born with fully developed eyes. 9 cm 3 5 to 12 cm 4 7.
One with eyes and one without any eyes. Because mexican cavefish are a variant of the mexican tetra the fish can interbreed with some of the surface dwelling fish migrating and joining the cave populations the study showed. Over the past few million years blind forms of the mexican tetra astyanax mexicanus have evolved in caves.
There are more than 200 scientifically described species of obligate cavefish found on all continents except antarctica. They range from texas to mexico with the sighted version from mexico to panama. There is no need for eye sight in the pitch black caves so they have evolved to adapt to these conditions.
Hence the fish is commonly known as blind cavefish or blind ave blind cave tetra. Mexico guatemala usa biotope. 20 to 25 c or 68 to 77 f ph.
Related terms are subterranean fish troglomorphic fish troglobitic fish stygobitic fish phreatic fish and hypogean fish. One such process in mexican blind cavefish is a phenomenon called pleiotropy in which genes usually involved in eye development are reassigned to features more useful to life in caves such as. Mexican tetra blind cave fish.
The mexican tetra astyanax mexicanus also known as the blind cave fish blind cave characin and blind cave tetra is a freshwater fish of the family characidae of the order characiformes.
