Radix auricularia Temporal range: [1] | |
---|---|
A shell of Radix auricularia | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Heterobranchia |
Superorder: | Hygrophila |
Family: | Lymnaeidae |
Genus: | Radix |
Species: | R. auricularia |
Binomial name | |
Radix auricularia | |
Synonyms | |
|
Radix auricularia, the big-ear radix, is a species of medium-sized freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae. [4]
Radix auricularia is the type species of the genus Radix .
Forms of Radix auricularia include: [5]
The shell is thin, roundly ovate and very inflated, such that the last whorl comprises 90% of its volume. [6] [7] [8]
The shell has a rounded and broad spire that pinches in steeply at the apex. The spire short, conic, very small compared with the body whorl. [1]
There are 4–5 whorls with deep sutures between them. [6] [7] The whorls are convex, inflated, smooth and rapidly increasing. The body whorl is large and spreading. The surface is shining, lines of growth are fine, wavy, crowded, with occasionally a heavy ridge representing a rest period. Sutures are deeply impressed, channeled in some specimens. [1]
The color of the shell is yellow, beige or tan.
The ear-shaped aperture, which contains no operculum, is around 5 times higher than the spire. [7] [8] [9] The aperture is very large, ovate, occupying four-fifths of the length of the entire shell. It is rounded above and flaring in old specimens below. The peristome is thin and sharp. The columella is sigmoid with a plait across the middle, which is reflected over the umbilicus. [1]
The umbilicus is either wide or covered. Usually the umbilicus is narrow, deep, nearly closed. The epidermis is sometimes marked by light and dark lines of color, alternating. [1]
The shell of the species can grow to ~30 mm in height [7] and 25 mm in width [6] as a full grown adult. However, most individuals in a population only grow to approximately half the maximum size. [6] The width of the shell is from 12 to 18 mm, and the height of the shell is 14–24 mm. [5] The shell of Radix auricularia has a width to length ratio greater than 0.75.
The body is flecked with small white spots on the back of the head and tentacles, but not on the foot. [1] The mantle is pigmented with a line of dark spots along its edge, [10] irregular spots which show through the shell. The foot is roundly elongated, 18 × 11 mm. [1] [11]
The head is broad, auriculated. [1] This species also has tentacles that are large, flat, lobate, triangular, fan-shaped and wider than they are high. [1] [12]
The blood contains blue hemocyanin. [13] The heart pulsations are slow and regular: thirty-four per minute. The animal is slow and deliberate in its movements. [1]
Radix auricularia is native to Europe and most of the Palearctic including Oman, Tibet and Vietnam. [7]
In Europe it occurs in:
In Asia it occurs across the East Palearctic and in
Radix auricularia is an introduced species in the United States and New Zealand. [17]
In the Mid-Atlantic Region it is found in the Charles River in Massachusetts, Cayuga Lake and the Hudson River in New York State, in various ponds in New Jersey, New York, and Pennsylvania, and in Lake Champlain in Vermont. [17]
In the Great Lakes Region: The first record of Radix auricularia in North America is from the Hudson River (which is connected through the New York Canal System to Lakes Erie and Ontario) near Troy, New York, before 1869. [18] The next record is from Lincoln Park, Chicago, beside Lake Michigan in 1901. [18] Subsequently, it was found in Lake Erie and a tributary stream in 1911 and in 1948, and in Lake Ontario in 1930. [18] It is also reported from Lake Huron. [19]
This species has shown a potential to adapt to new environments within large lakes, as indicated by its recent history in Lake Baikal, Russia, where this introduced species was previously restricted to shallow bays and floodplain areas, but has recently been able to colonize the rocky drop-off in the lake. [20] The shells of those snails in the new habitat have a more inflated aperture and are more compact than those in the shallow zones, indicating that wave action may have selected for snails with a stronger suctioning foot in the newly colonized habitat. [20]
This species is found in freshwater lakes, ponds, and slow-moving rivers with mud bottoms. Radix auricularia can live on boulders or vegetation in low or high-flow environments, and is capable of tolerating anoxic conditions, but it tends to prefer very lentic waters in lakes, bogs or slow rivers where there is a silt substrate. [6] [7] [21]
It has been found in environments with a pH from 6.0 to 7.1. [7] [22] Its average thermal preference is ~19 °C, but there is great fluctuation around this mean, depending on the photoperiod for the time of year. [23] In Great Britain, the species is restricted to hard water. [24] It can tolerate polysaprobic waters, or areas of major pollution and anoxia with high concentrations of organic matter, sulfides and bacteria. [25] [26]
Radix auricularia is in the family Lymnaeidae, which consists of scrapers and collector-gatherers. This species feeds on such items as detritus, Cladophora spp. (algae), and sand grains. [24]
Like almost all pulmonate snails, it is a hermaphrodite. It undergoes oogenesis in spring as the daylight hours increase, and spermatogenesis in late summer and early fall as the daylight hours decrease. [27] It is iteroparous, breeding biennially. [24] It lays its eggs in clumps of 50 to 150 eggs. [28] Eggs develop faster as temperature increases from 10 °C upward, but the eggs fail to survive and develop when the water temperature reaches 36 °C. [29]
Various lymnaeid snails, including Radix auricularia, are vectors for a diverse range of parasites, particularly trematodes. [30] About 80% specimens of Radix auricularia from population near Wielkopolska National Park were found to contain trematodes. [31]
Radix auricularia serves as a host to numerous parasites including:
As a host for:
Some of these parasites may infect humans.
One study found that average shell height and infection severity with Trichobilharzia spp. are positively related. [45]
In its native habitat, this species preys on eggs of the parasite Ascaris suum , which survive and develop after passage through the gut, and are dispersed widely, due to the activity of the snail. [46]
Fasciola hepatica, also known as the common liver fluke or sheep liver fluke, is a parasitic trematode of the class Trematoda, phylum Platyhelminthes. It infects the livers of various mammals, including humans, and is transmitted by sheep and cattle to humans the world over. The disease caused by the fluke is called fasciolosis or fascioliasis, which is a type of helminthiasis and has been classified as a neglected tropical disease. Fasciolosis is currently classified as a plant/food-borne trematode infection, often acquired through eating the parasite's metacercariae encysted on plants. F. hepatica, which is distributed worldwide, has been known as an important parasite of sheep and cattle for decades and causes significant economic losses in these livestock species, up to £23 million in the UK alone. Because of its relatively large size and economic importance, it has been the subject of many scientific investigations and may be the best-known of any trematode species. F. hepatica's closest relative is Fasciola gigantica. These two flukes are sister species; they share many morphological features and can mate with each other.
Fasciola gigantica is a parasitic flatworm of the class Trematoda, which causes tropical fascioliasis. It is regarded as one of the most important single platyhelminth infections of ruminants in Asia and Africa. Estimates of infection rates are as high as 80–100% in some countries. The infection is commonly called fasciolosis.
Lymnaea stagnalis, better known as the great pond snail, is a species of large air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae. The great pond snail is a model organism to study parasitology, neurology, embryonal development and genetic regulation.
Galba truncatula is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
Planorbarius corneus, common name the great ramshorn, is a relatively large species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails, or planorbids, which all have sinistral or left-coiling shells.
Lymnaeidae, common name the pond snails, is a taxonomic family of small to large air-breathing freshwater snails, aquatic pulmonate gastropod mollusks, that belong to the clade Hygrophila.
Lymnaea is a genus of small to large-sized air-breathing freshwater snails, aquatic pulmonate gastropod mollusks in the subfamily Lymnaeinae ( of the family Lymnaeidae, the pond snails.
Radix is a genus of air-breathing freshwater snails, aquatic pulmonate gastropods in the family Lymnaeidae, the pond snails.
Pseudosuccinea columella, the American ribbed fluke snail, is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
Omphiscola glabra, commonly known as the pond mud snail, is a species of small to medium-size, air-breathing, freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae. Omphiscola glabra is the type species of the genus Omphiscola.
Radix balthica, common name the wandering snail, is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
Radix rubiginosa is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod in the family Lymnaeidae, the pond snails.
Indoplanorbis is a genus of air-breathing freshwater snail. Its only member species is Indoplanorbis exustus, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails. The species is widely distributed across the tropics. It serves as an important intermediate host for several trematode parasites. The invasive nature and ecological tolerance of Indoplanorbis exustus add to its importance in veterinary and medical science.
Radix luteola is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.
Lymnaea acuminata is a species of freshwater snail in the family Lymnaeidae. It is native to South Asia, where it occurs in Bangladesh, Burma, India, Nepal, and Pakistan. There it is a widespread and common species.
Hypoderaeum conoideum is a species of digenetic trematodes in the family Echinostomatidae.
Radix natalensis is a species of freshwater snail, an aquatic gastropod mollusc in the family Lymnaeidae.
Galba schirazensis is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
Galba neotropica is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
Austropeplea viridis is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae, the pond snails.
This article incorporates public domain text from references. [1] [17]