Kanab ambersnail
Encyclopedia
The Kanab ambersnail, scientific name Oxyloma haydeni kanabensis or Oxyloma kanabense, is a critically endangered
subspecies
or species
of small, air-breathing land snail
, a terrestrial
pulmonate gastropod mollusc in the family
Succineidae
, the amber snails. The amber snails take their common name from the shell, which is translucent and when empty is often amber or brownish in color.
This species is endemic to the United States
, specifically the state of Arizona
and Utah
, where it was first collected in the early 20th century. It has been listed as endangered on the United States Fish and Wildlife Service list of endangered species
since 8 August 1991.
This snail lives in wetland
s, springs
, and seeps
, and only two of its natural habitat
s are known to exist: Three Lakes, a meadow
near Kanab, Utah
, and Vasey's Paradise
, a spring
along the Colorado River
within Grand Canyon National Park
. In its natural habitat it is rather polyphagous, feeding mainly on bacteria
, plant
s and fungi, and reproduces during the summer.
Now considered a Critically Endangered
species on the IUCN Red List
of Threatened Species due to a series of factors (such as anthropic influence), the Kanab ambersnail has been reintroduced to three springs above the historic high water level along the Colorado River
.
from: "The Greens", 10 kilometres (6.2 mi) above Kanab, Utah
on Kanab Wash, on a wet ledge among moss and cypripediums. These specimens were originally placed in the species Succinea hawkinsi.
Pilsbry (1948) transferred these specimens to the genus Oxyloma
and erected the subspecies kanabensis in the species haydeni for them. Arthur Clarke (1991) notes that Pilsbry’s decision to accord the Kanab ambersnail subspecific status was
preliminary, and that, as Pilsbry himself noted, “its taxonomic status should be reevaluated.”
Clarke (1991) and Shei K. Wu (Colorado Museum of Natural History, Boulder, Colorado, pers. comm. 1992, 1995) suggest that the Kanab ambersnail may deserve full species status. Earle Spamer (Academy of Natural Sciences of Philadelphia, Philadelphia, Pennsylvania, pers. comm. 1994) stated that although current published mollusk checklists (Turgeon et al. 1988 and Groombridge 1993) treat the Kanab ambersnail at species level rather that as a subspecies, nonetheless, until the criteria are derived (and published) by which the taxon can be known to be a separate species, it should continue to be called by its original name, the one published by Pilsbry (1948): Oxyloma haydeni spp. kanabensis. Despite this, NatureServe
does list this taxon as a species.
is a light amber color. The live snail has a mottled grayish-amber to yellowish-amber colored shell. The shell is dextral (right-handed spiral), thin-walled, with an elevated spire
and a broad, patulous (expanded) aperture
. Fully mature individuals are about 14 to 19 mm (0.5 to 0.75 inch)
long, 7 to 9 mm (0.25 to 0.33 inch) in diameter, with 3.25 to 3.75 whorls
in a drawn out spire.
Its eyes are borne at the ends of long peduncles (stalks), while the tentacle
s are reduced to small protuberances at the base of the eye
stalks.
s, the (American robin
), and deer mice.
was destroyed in a flood
, and a more disastrous previous flood in 1994 had probably already threatened the snail's habitat. The suitable area for habitat in Three Lakes is believed to extend to an area 1.3 km long, and 90 m wide, and genetic diversity seems to indicate that the area is more stable than Vasey's Paradise
. However their redistribution is also affected by the presence of their host plants and rock ledges.
Three Lakes, a privately-owned wet meadow near Kanab
, is one of only two natural habitats for the Kanab Ambersnail. The snail's habitat is threatened by commercial development by the owner of Three Lakes.
Despite being air-breathing molluscs, they can survive for up to 32 hours in cold, highly-oxygenated water, which may have helped to disperse its population around the Colorado Valley area since a controlled release was conducted in 1998.
and watercress
, but also sedge
s and rushes
. It feeds on plant
tissue, fungi, algae
, and bacteria
, using its radula
to scrape off food.
. The latter was not discovered until 1991 when a survey of mollusks in the area was conducted. There was formerly a third population present in Kanab, Utah, but it is believed to have become extirpated through the destruction of its habitat.
(USFWS) has listed the Kanab ambersnail as endangered since 1992.
The Kanab ambersnail is evaluated as Critically Endangered
on the IUCN Red List
of Threatened Species.
In Utah, its habitat was threatened by commercial development, whereas the Grand Canyon population is threatened by discharges from the Glen Canyon Dam
which can sweep the snail and its habitat downstream.
Reintroduction
releases have been conducted at three sites along the Colorado river, each releasing 150 snails. The first of these releases was conducted in September 1998, and all sites were sufficiently high enough to not be flooded by normal dam activity. A second release was conducted at the same three sites in July 1999 to boost population densities and improve genetic variability
, but only one of the three sites, Upper Elves Chasm, has established a new population.
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
or species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of small, air-breathing land snail
Land snail
A land snail is any of the many species of snail that live on land, as opposed to those that live in salt water and fresh water. Land snails are terrestrial gastropod mollusks that have shells, It is not always an easy matter to say which species are terrestrial, because some are more or less...
, a terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
pulmonate gastropod mollusc in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Succineidae
Succineidae
Succineidae are a family of small to medium-sized, air-breathing, land snails , terrestrial pulmonate gastropod molluscs. They are commonly called amber snails because their thin fragile shells are translucent and amber-colored...
, the amber snails. The amber snails take their common name from the shell, which is translucent and when empty is often amber or brownish in color.
This species is endemic to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, specifically the state of Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
and Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
, where it was first collected in the early 20th century. It has been listed as endangered on the United States Fish and Wildlife Service list of endangered species
United States Fish and Wildlife Service list of endangered species
This list contains only the bird and mammal species described as endangered by the United States Fish and Wildlife Service. It contains species not only in the U.S. and its territories, but also species only found abroad. It does not contain fish, amphibians, reptiles, plants, or invertebrates,...
since 8 August 1991.
This snail lives in wetland
Wetland
A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....
s, springs
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
, and seeps
Seep (hydrology)
A Seep is a moist or wet place where water, usually groundwater, reaches the earth's surface from an underground aquifer.-Description:Seeps are usually not of sufficient volume to be flowing beyond their above-ground location. They are part of the limnology-geomorphology system...
, and only two of its natural habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
s are known to exist: Three Lakes, a meadow
Pasture
Pasture is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep or swine. The vegetation of tended pasture, forage, consists mainly of grasses, with an interspersion of legumes and other forbs...
near Kanab, Utah
Kanab, Utah
Kanab is a city in and the county seat of Kane County, Utah, United States. The area was first settled in 1864 and the town was founded in 1870 when ten Mormon families moved into the area. The population was 3,564 at the 2000 census...
, and Vasey's Paradise
Vasey's Paradise
Vasey's Paradise also known as "Vaseys Paradise", is an oasis approximately 1.5 miles below the Mile 30 Sand Bar on the Colorado River in Coconino county, Arizona, United States. In a semi desert region it supports dense vegetation watered by waterfalls emanating from groundwater emerging from the...
, a spring
Spring (hydrosphere)
A spring—also known as a rising or resurgence—is a component of the hydrosphere. Specifically, it is any natural situation where water flows to the surface of the earth from underground...
along the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
within Grand Canyon National Park
Grand Canyon National Park
Grand Canyon National Park is the United States' 15th oldest national park and is located in Arizona. Within the park lies the Grand Canyon, a gorge of the Colorado River, considered to be one of the Wonders of the World. The park covers of unincorporated area in Coconino and Mohave counties.Most...
. In its natural habitat it is rather polyphagous, feeding mainly on bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s and fungi, and reproduces during the summer.
Now considered a Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
species on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
of Threatened Species due to a series of factors (such as anthropic influence), the Kanab ambersnail has been reintroduced to three springs above the historic high water level along the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
.
Taxonomy
Specimens of the Kanab ambersnail were first collected in 1909 by James FerrissJames Ferriss
James Henry Ferriss was an amateur conchologist. According to Henry Augustus Pilsbry, Ferriss was "the fore-most of American landshell collectors... as a collector he has probably never been surpassed."...
from: "The Greens", 10 kilometres (6.2 mi) above Kanab, Utah
Kanab, Utah
Kanab is a city in and the county seat of Kane County, Utah, United States. The area was first settled in 1864 and the town was founded in 1870 when ten Mormon families moved into the area. The population was 3,564 at the 2000 census...
on Kanab Wash, on a wet ledge among moss and cypripediums. These specimens were originally placed in the species Succinea hawkinsi.
Pilsbry (1948) transferred these specimens to the genus Oxyloma
Oxyloma
Oxyloma is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Succineidae, the ambersnails.-Species:The genus Oxyloma includes the following species and subspecies:...
and erected the subspecies kanabensis in the species haydeni for them. Arthur Clarke (1991) notes that Pilsbry’s decision to accord the Kanab ambersnail subspecific status was
preliminary, and that, as Pilsbry himself noted, “its taxonomic status should be reevaluated.”
Clarke (1991) and Shei K. Wu (Colorado Museum of Natural History, Boulder, Colorado, pers. comm. 1992, 1995) suggest that the Kanab ambersnail may deserve full species status. Earle Spamer (Academy of Natural Sciences of Philadelphia, Philadelphia, Pennsylvania, pers. comm. 1994) stated that although current published mollusk checklists (Turgeon et al. 1988 and Groombridge 1993) treat the Kanab ambersnail at species level rather that as a subspecies, nonetheless, until the criteria are derived (and published) by which the taxon can be known to be a separate species, it should continue to be called by its original name, the one published by Pilsbry (1948): Oxyloma haydeni spp. kanabensis. Despite this, NatureServe
NatureServe
NatureServe is a non-profit conservation organization whose mission is to provide the scientific basis for effective conservation action. NatureServe and its network of natural heritage programs are the leading source for information about rare and endangered species and threatened ecosystems in...
does list this taxon as a species.
Description
The Kanab ambersnail is a terrestrial snail in the family Succineidae. The empty shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is a light amber color. The live snail has a mottled grayish-amber to yellowish-amber colored shell. The shell is dextral (right-handed spiral), thin-walled, with an elevated spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
and a broad, patulous (expanded) aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
. Fully mature individuals are about 14 to 19 mm (0.5 to 0.75 inch)
long, 7 to 9 mm (0.25 to 0.33 inch) in diameter, with 3.25 to 3.75 whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
in a drawn out spire.
Its eyes are borne at the ends of long peduncles (stalks), while the tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
s are reduced to small protuberances at the base of the eye
stalks.
Ecology
The natural predators of this snail are passerinePasserine
A passerine is a bird of the order Passeriformes, which includes more than half of all bird species. Sometimes known as perching birds or, less accurately, as songbirds, the passerines form one of the most diverse terrestrial vertebrate orders: with over 5,000 identified species, it has roughly...
s, the (American robin
American Robin
The American Robin or North American Robin is a migratory songbird of the thrush family. It is named after the European Robin because of its reddish-orange breast, though the two species are not closely related, with the European robin belonging to the flycatcher family...
), and deer mice.
Habitat
In 1996, 16% of the Ambersnail's habitat at Vasey's ParadiseVasey's Paradise
Vasey's Paradise also known as "Vaseys Paradise", is an oasis approximately 1.5 miles below the Mile 30 Sand Bar on the Colorado River in Coconino county, Arizona, United States. In a semi desert region it supports dense vegetation watered by waterfalls emanating from groundwater emerging from the...
was destroyed in a flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
, and a more disastrous previous flood in 1994 had probably already threatened the snail's habitat. The suitable area for habitat in Three Lakes is believed to extend to an area 1.3 km long, and 90 m wide, and genetic diversity seems to indicate that the area is more stable than Vasey's Paradise
Vasey's Paradise
Vasey's Paradise also known as "Vaseys Paradise", is an oasis approximately 1.5 miles below the Mile 30 Sand Bar on the Colorado River in Coconino county, Arizona, United States. In a semi desert region it supports dense vegetation watered by waterfalls emanating from groundwater emerging from the...
. However their redistribution is also affected by the presence of their host plants and rock ledges.
Three Lakes, a privately-owned wet meadow near Kanab
Kanab, Utah
Kanab is a city in and the county seat of Kane County, Utah, United States. The area was first settled in 1864 and the town was founded in 1870 when ten Mormon families moved into the area. The population was 3,564 at the 2000 census...
, is one of only two natural habitats for the Kanab Ambersnail. The snail's habitat is threatened by commercial development by the owner of Three Lakes.
Despite being air-breathing molluscs, they can survive for up to 32 hours in cold, highly-oxygenated water, which may have helped to disperse its population around the Colorado Valley area since a controlled release was conducted in 1998.
Feeding habits
The Kanab ambersnail is typically found on host plants, primarily the scarlet monkeyflowerMimulus
Mimulus is a diverse plant genus, the monkey-flowers and musk-flowers. The about 150 species are currently placed in the family Phrymaceae. The genus has traditionally been placed in Scrophulariaceae. The removal of Mimulus from that family has been supported by studies of chloroplast DNA first...
and watercress
Watercress
Watercresses are fast-growing, aquatic or semi-aquatic, perennial plants native from Europe to central Asia, and one of the oldest known leaf vegetables consumed by human beings...
, but also sedge
Cyperaceae
Cyperaceae are a family of monocotyledonous graminoid flowering plants known as sedges, which superficially resemble grasses or rushes. The family is large, with some 5,500 species described in about 109 genera. These species are widely distributed, with the centers of diversity for the group...
s and rushes
Juncus
Juncus is a genus in the plant family Juncaceae. It consists of some 200 to 300 or more species of grassy plants commonly called rushes...
. It feeds on plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
tissue, fungi, algae
Algae
Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
, and bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, using its radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
to scrape off food.
Life cycle
Like all pulmonate land snails, ambersnails are hermaphroditic, having both male and female reproductive systems, and are believed to be capable of self-fertilization. In the wild they live for between 12 and 15 months. Young snails enter dormancy between October and November, becoming active again in March and April. Mature snails reproduce in the summer months.Population
Only two wild populations of the snail are known to exist, specifically, Three Lakes near Kanab, Utah and Vasey's ParadiseVasey's Paradise
Vasey's Paradise also known as "Vaseys Paradise", is an oasis approximately 1.5 miles below the Mile 30 Sand Bar on the Colorado River in Coconino county, Arizona, United States. In a semi desert region it supports dense vegetation watered by waterfalls emanating from groundwater emerging from the...
. The latter was not discovered until 1991 when a survey of mollusks in the area was conducted. There was formerly a third population present in Kanab, Utah, but it is believed to have become extirpated through the destruction of its habitat.
Conservation
The Kanab ambersnail was proposed for emergency listing in 1991, and the United States Fish and Wildlife ServiceUnited States Fish and Wildlife Service
The United States Fish and Wildlife Service is a federal government agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats...
(USFWS) has listed the Kanab ambersnail as endangered since 1992.
The Kanab ambersnail is evaluated as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
of Threatened Species.
In Utah, its habitat was threatened by commercial development, whereas the Grand Canyon population is threatened by discharges from the Glen Canyon Dam
Glen Canyon Dam
Glen Canyon Dam is a concrete arch dam on the Colorado River in northern Arizona in the United States, just north of Page. The dam was built to provide hydroelectricity and flow regulation from the upper Colorado River Basin to the lower. Its reservoir is called Lake Powell, and is the second...
which can sweep the snail and its habitat downstream.
Reintroduction
Reintroduction
Reintroduction is the deliberate release of a species into the wild in zones formerly inhabited by said species but where it has disappeared from for a number of reasons, from captivity or relocated from other areas where the species still survives in...
releases have been conducted at three sites along the Colorado river, each releasing 150 snails. The first of these releases was conducted in September 1998, and all sites were sufficiently high enough to not be flooded by normal dam activity. A second release was conducted at the same three sites in July 1999 to boost population densities and improve genetic variability
Genetic variability
Genetic variability is a measure of the tendency of individual genotypes in a population to vary from one another. Variability is different from genetic diversity, which is the amount of variation seen in a particular population. The variability of a trait describes how much that trait tends to...
, but only one of the three sites, Upper Elves Chasm, has established a new population.
External links
- Species profile of Kanab ambersnail (Oxyloma haydeni kanabensis) at U.S. Fish & Wildlife Service webpage
- http://www.gf.state.az.us/w_c/nongame_kanab_ambersnail.shtml
- 1991. Endangered and Threatened Wildlife and Plants; Emergency Rule to List the Kanab Ambersnail as Endangered / RIN 1018-AB67. United States Fish and Wildlife Service.