• View of Grand Canyon National Park at sunset from the South Rim

    Grand Canyon

    National Park Arizona

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  • Increasing Chances of Showers and Thunderstorms Through the Week.

    Monsoonal weather patterns have moved into the Grand Canyon area decreasing fire danger. As a result, on Tuesday, July 8 at 8 a.m. fire managers lifted fire restrictions within Grand Canyon National Park. More »

  • Two Bats Collected in the Park Have Tested Positive for Rabies

    One on the North Kaibab Trail and the other at Tusayan Ruin/Museum. Rabies can be prevented if appropriate medical care is given following an exposure. Any persons having physical contact with bats in Grand Canyon National Park, please follow this link. More »

Mollusks

Riparian: Eleven aquatic and 26 terrestrial species of mollusks have been identified in and around Grand Canyon National Park. Of the aquatic species, two are bivalves (clams) and nine are gastropods (snails). All of the aquatic snails located in Grand Canyon are of the subclass Pulmonata. This means that although they are aquatic, they are lung breathers. They do not have gills, but have a large pulmonary sac which they use for gaseous exchange. Three of the nine snail species found here are lymnaeids of the genus Fossaria. Lymnaeid snails have shells that coil to the right. Physids, of which Grand Canyon has five species of the genus Physella, are snails that possess shells that coil to the left. The remaining aquatic snail species is called a planorbid of the genus Gyralus. Planorbid snail shells are coiled in a single plane, appearing flatter than most snails.

The two aquatic bivalves are thought to be introduced species, since they were found in a cobble bar near Lees Ferry just downriver from the Glen Canyon Dam. These two clam species are of the genus Pisidium.

Twenty-six species of terrestrial gastropods have been identified, primarily land snails and slugs. The ambersnail family, Succineidae, is of special interest in Grand Canyon. This family of land snails gets its common name, "amber snail," from the snails' characteristic orange colored shell. One species of amber snail found in the park, the Kanab Ambersnail (Oxyloma haydeni kanabensis), is listed as endangered by the U.S. Fish and Wildlife Service. Only two populations of this species are known to exist.
 

Did You Know?

GRAND CANYON WONDER OF THE WORLD

The Grand Canyon is considered one of the natural wonders of the world largely because of its natural features. The exposed geologic strata, layer upon layer, rise over a mile above the river, representing one of the most complete records of geological history that can be seen anywhere in the world. More...