Kanab Ambersnail

A Kanab Ambersnail moving along the edge of a dime for scale.

AZ Game & Fish

The Kanab Ambersnail (Oxyloma haydeni kanabensis)is one of Grand Canyon National Park's endangered species. This terrestrial snail has an amber colored shell typical of the family of mollusks known as Succineidae, in the class Gastropoda. There are only two known natural populations of the Kanab Ambersnail: one in a series of small ponds near the city of Kanab, Utah and the other in Grand Canyon National Park at a large spring along the Colorado River called Vasey's Paradise. These populations are considered relicts from the Pleistocene ice age when springs, seeps and wetland habitat in the southwest was more abundant.

The Kanab Ambersnail is dependent upon wetland vegetation for food and shelter. It is often found in association with monkeyflower, watercress, sedges and rushes. This species of land snail feeds on plant tissue, bacteria, fungi and algae. It scrapes this food off of plants by means of a radula or rasp tongue.

Kanab Ambersnails are hermaphroditic, meaning they possess both male and female reproductive parts. They are capable of self-fertilizing if other snails aren't around for mating. These snails have an annual life cycle, living 12-15 months, with reproduction occurring in the summer months. Baby snails measure about 1/10th of an inch long when they emerge from the gelatinous egg masses. They will grow to be 1 inch long upon maturity. During the winter, ambersnails recede into their shells and become dormant until environmental conditions prompt them to emerge again in the spring. Many die over the winter from cold temperatures.

Since the construction of the Glen Canyon Dam upriver from Grand Canyon National Park, Colorado River flows have been controlled by the Bureau of Reclamation. These flows have averaged around 18,000 cfs, much lower than natural, pre-dam spring runoff flows of over 100,000 cfs. In the absence of the pre-dam, beach-scouring high flows, the Kanab Ambersnail's habitat at Vasey's Paradise expanded down to the Colorado River's edge. This more stable environment allowed the snail population to prosper until recent management strategies changed. Experimental dam releases of 45,000 cfs have been allowed in an attempt to build downriver beaches. During these high experimental flows, Kanab Ambersnail individuals and their habitat get washed away downstream.

In order to protect this endangered species, the National Park Service and the Arizona Game and Fish Department have teamed up in an attempt to establish new wild populations of Kanab Ambersnails in three additional natural springs along the Colorado River. These sites are located above the historic high water mark, so that the new populations will be protected from the experimental scouring floods.

 

Related Information

Grand Canyon Invertebrate Species Collection (1.7MB XLS File)

Grand Canyon Threatened & Endangered Species List (52kb PDF File)

Arizona Game and Fish Web Site