Get complete information on Cave Adaptations

The caves are abandoned channels of Under-ground Rivers found in limestone regions. These caves forming animal habitat.

This lime stone is soluble in water so that instead of being confined to the surface of the earth, the water sink underground, enlarging the cervices through which they descend until the level of ground-water is reached, when the movement becomes lateral and subtarranean channels of considerable magnitude are formed. Distribution of Caves

In North America there is a large cave area extending through parts of Indiana, Kentucky, Tennessee and Missouri, embracing the so- called Mammoth cave region.

In Edmonson country, Kentucky, there are said to be at least 4000 sink holes or pipes through which surface waters pass underground and 500 caves are known. Wyandotte cave in Indiana, Luray Cavern in Virginia and Carlsbad Caverns are noted.

In Cuba there are extensive caves in communication with the sea. In Europe there are other caves. Few caverns exist in the glaciated regions of Europe or N. America, almost all of them lying south of the great terminal marine. _

Cave regions: The caves can be divided into three regions:

(i) Twilight (Transitional region). It is the region lying within the mouth of the cave between the outer world and the real cave. Therefore, in this region, conditions vary.

(ii) Region of Fluctuating Temperature. Here, the diurnal or seasonal variations of heat and cold can be felt.

(iii) Inner Cave Region. In this region, light is absent and the temperature remains constant. The moisture is uniform here.

The Fauna of Caves can be divided into two types:

(a) Temporary Fauna:

These show little or no special adaptations to deep cave life as they are temporary visitor. Viz. Myotis lucifugus of the brown bat.

(b) Permanent Fauna:

This includes those animals which permanently live in the caves. Among fishes a large number of cave dwellers are there e.g. Cave catfish (Gronias nigrilabis), Dismal swampfish, Chologaster cornutus, Ambloyoposis spelaeus, Typhilichthys subterraneus etc.

In Amphibia only the Salamanders are cave dwellers (Spelerpes maculicauda, S. Stejnegeri etc.) In Reptiles and birds there is no example of permanent cave-dweller. Besides bats only one mammal called white footed mouse Peromyscus leucopus is a truely cave dweller. Following are cave adaptations in cave dwellers: 1. Loss of pigmentation. A general effect of the lack of light is the bleaching of the skin of cave dwellers, examples are Stygicola (fish) and Proteus (Amphibian).

2. Reduction of eyes:

Eyes may become reduction or degenerate, may be covered by other tissues or become entirely obsolate. Blind forms are never the less sensative to light. Gronians is partially blind fish. Typhlichthys is an another animal in which eyes are functional in the young but become defective in the adult. Amphyopsis is a totally blind fish. Among amphibians, the blind form is Proteus and Typhlomolge with degenerate eyes. To compensate the loss of vision, tactile organs or sense of smell is highly developed.

3. Organ of digestion:

The absence of light means very poor vegetation and hence, there is scarcity of food. The organs of digestion so modified that they completely utilize the food which the animal takes.

4. Slender bodies: Cave dwellers have slander and attenuated appendages eg. Proteus etc.