The Yucatan Peninsula extends northward from Central
America and includes the Mexican states of Campeche, Yucatan and Quintana Roo.
It is bordered to the west and north by the Gulf of Mexico and to the east by
the Caribbean Sea. Northern Yucatan is low and relatively flat with no surface
rivers or streams. Rocks along the coast are of Pleistocene and Holocene age,
while older Miocene and Eocene deposits are exposed farther inland.
Caves and karst features are common in nearly all
parts of the Peninsula. The most notable karst feature is the cenote. Cenote is
derived the Mayan word "dzonot" and refers to any subterranean chamber that contains permanent
water. While some cenotes are vertical, water-filled shafts, others are caves
that contain pools and underwater passageways in their interior.
Cave exploration in the Yucatan may have begun by the
Mayans as much as 3,000 years ago. The scarcity of surface water in the Yucatan
has necessitated use of cenotes and caves as primary water sources. Indeed,
pottery shards, charcoal, torches, and artwork can be found in virtually all
parts of the caves. Since caves and cenotes were the only source of water, and
therefore essential to survival, they played a vital role in the life of the
Maya. Caves were used as sources of drinking water, sources of "virgin" water
for religious rites, burial and/or sacrificial sites, art galleries, places of
refuge, and mines for clay or minerals.
Fortyone stygobitic species have been identified from Yucatan caves including 39 crustaceans and two fish. Most have marine origins and many belong to the same genera as cave species from Cuba and the Bahamas. In order of abundance, the fauna includes 11 species of shrimps, 10 copepods, 6 isopods and 5 amphipods.