The Banff Springs snail (''Physella johnsoni'') is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of small air-breathing
freshwater snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...
in the family
Physidae
Physidae, common name the bladder snails, is a monophyletic taxonomic family of small air-breathing freshwater snails, aquatic pulmonate gastropod molluscs in the superfamily Lymnaeoidea .MolluscaBase eds. (2021). MolluscaBase. Physidae Fitzin ...
.
Based on molecular research, it appears that ''Physella johnsoni'' separated out as a species from ''
Physella gyrina'' about 10,000 years ago.
Description, habitat and distribution
These
aquatic pulmonate
Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includ ...
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusk
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...
s are approximately the size of unpopped
corn kernels
Corn kernels are the fruits of corn (called maize in many countries). Maize is a grain, and the kernels are used in cooking as a vegetable or a source of starch. The kernel comprise endosperm, germ, pericarp, and tip cap.
One ear of corn c ...
. The largest ones are only about one centimetre long, and like all of the Physidae, the shells are sinistral or coiled left-handed. The snails' diet consists of
periphyton
Periphyton is a complex mixture of algae, cyanobacteria, heterotrophic microbes, and detritus that is attached to submerged surfaces in most aquatic ecosystems. The related term Aufwuchs (German "surface growth" or "overgrowth") refers to the col ...
.
The Banff Springs snail was first identified in 1926 in the nine sulphurous
hot springs
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
of
Sulphur Mountain in
Banff National Park
Banff National Park is Canada's oldest National Parks of Canada, national park, established in 1885 as Rocky Mountains Park. Located in Alberta's Rockies, Alberta's Rocky Mountains, west of Calgary, Banff encompasses of mountainous terrain, wi ...
,
Alberta
Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...
, Canada, and has been found nowhere else. It is very unusual because it is adapted to life in
thermal springs
A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...
where the water is low in
oxygen
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as wel ...
and high in
hydrogen sulfide
Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...
, an environment too harsh for most animals to survive in. Since its discovery, its range has shrunk to just five of the nine hot springs.
Conservation
The reduction in Banff Spring snail population and range is likely attributable to human use of the hot springs, although fluctuating water temperature is also a factor. In April 1997 it became the first living
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
to be placed on Canada's national list of species at risk. In 2000 it was classified as endangered by
COSEWIC and the Canadian
Species at Risk Act
The ''Species at Risk Act'' (SARA) (the ''Act'') is a piece of Canadian federal legislation which became law in Canada on December 12, 2002. It is designed to meet one of Canada's key commitments under the International Convention on Biological D ...
listed it in the
List of Wildlife Species at Risk
The List of Wildlife Species at Risk currently has more than 800 entries for Canadian wild life species considered vulnerable; including 363 classified as endangered species, —190 threatened species, —235 special concern, and 22 extirpated ( ...
as being endangered in Canada.
[COSEWIC. 2005]
Canadian Species at Risk
Committee on the Status of Endangered Wildlife in Canada. 64 pp., page 13.
Parks Canada
Parks Canada (PC; french: Parcs Canada),Parks Canada is the applied title under the Federal Identity Program; the legal title is Parks Canada Agency (). is the agency of the Government of Canada which manages the country's 48 National Parks, th ...
is trying to protect the species through education, law enforcement, facility closure and scientific research. In 1996
Parks Canada
Parks Canada (PC; french: Parcs Canada),Parks Canada is the applied title under the Federal Identity Program; the legal title is Parks Canada Agency (). is the agency of the Government of Canada which manages the country's 48 National Parks, th ...
started a research and recovery program for the snail including the closure of the swimming pool at the
Cave and Basin National Historic Site
The Cave and Basin National Historic Site of Canada is located in the town of Banff, Alberta, within the Canadian Rocky Mountains, at the site of natural thermal mineral springs around which Canada's first national park, Banff National Park, w ...
. The goals of the program are to maintain self-sustaining populations of the snail, re-establish populations at all historic locations, and hopefully to downlist the species' status.
The snail population fluctuates seasonally. During times when the numbers are critically low, the snail is most vulnerable to human disturbances or natural disasters (like the spring temporarily drying up). While scientists do not know exactly why the population fluctuates so much, it is probably due to changes in water temperature and chemistry or changes to the bacteria and algae. It is estimated that the population varies between 1,500 and 15,000 snails. At its lowest points, the entire population of snails can fit in an ice cream cone, and at its highest, in a one-litre milk carton.
Conservation biologist Dwayne Lepitzki believes that the leading cause of the thermal springs drying up and the decline in snail population is climate change. Until 1996, the only recorded instance of any Sulphur Mountain thermal spring drying up was the Upper Hot Spring in 1923, and now it's a regular occurrence.
Every four weeks researchers and volunteers count the snails and analyse the water chemistry. There is also a captive breeding program being performed, and if it is successful, the snails will be introduced back to the two additional springs where the species was historically present. Eggs are currently hatching in captivity; the time from laying to hatching is four to eight days.
Snails were no longer present at
Upper Hot, Upper Middle, Kidney, and Vermilion Cool springs. However, they are now present at the Upper middle and Kidney due to Parks Canada's Recovery actions in 2002 for the Upper Middle and 2003 for the Kidney spring.
The snails are most populated at the
Cave and Basin National Historic Site
The Cave and Basin National Historic Site of Canada is located in the town of Banff, Alberta, within the Canadian Rocky Mountains, at the site of natural thermal mineral springs around which Canada's first national park, Banff National Park, w ...
.
See also
*
Banff longnose dace
The Banff longnose dace (''Rhinichthys cataractae smithi'') was a diminutive (about five cm. long) version of the eastern longnose dace, its range restricted to a small marsh fed by two hot springs on Sulphur Mountain in Banff National Park i ...
References
External links
Parks Canada website
{{Taxonbar, from=Q3061785
Physidae
Molluscs of Canada
Gastropods described in 1926
Endemic fauna of Canada