Anisus vorticulus | |
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Shells of Anisus vorticulus | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Mollusca |
Class: | Gastropoda |
Subclass: | Heterobranchia |
Superorder: | Hygrophila |
Family: | Planorbidae |
Genus: | Anisus |
Species: | A. vorticulus |
Binomial name | |
Anisus vorticulus | |
Anisus vorticulus (lesser ramshorn snail or little whirlpool ramshorn snail) is a species of minute, air-breathing, freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ramshorn snails.
The lesser ramshorn snail is a very small species growing to a maximum diameter of 5 mm (0.2 in). The shell lacks a keel and the peripheral angle is relatively prominent, with a slender, narrow periostracal fringe. [3]
Anisus vorticulus occurs in Czech Republic [4] - critically endangered (CR). [5] Its Conservation status in 2004–2006 is bad (U2) in report for European commission in accordance with Habitats Directive. [6] England - vulnerable (VU), [7] listed in List of endangered species in the British Isles. It is currently the focus of a Back from the Brink project. [8] Ireland, Germany - critically endangered (vom Aussterben bedroht), [9] Netherlands, [10] Poland, Slovakia - critically enangered, [4] [11] Latvia and Croatia - in the Krka National Park. First finding of this species in Croatia was in 2009. [1] [12]
In the British Isles, this species is restricted to a small number of sites in the Norfolk Broads and the Pevensey Levels and Arun Valley in Sussex and Surrey. [1] [13]
This small snail lives in pools with standing water and in oxbow lakes, but these biotopes are threatened because of sedimentation and ecological succession. It favours ditches with much aquatic flora but little emergent vegetation. Invasive plants such as floating marsh pennywort, (Hydrocotyle ranunculouides), that sometimes chokes ditches, and the Himalayan balsam (Impatiens glandulifera) are particularly harmful. [1]
This species often lives in places where there is abundant duckweed Lemna spp. [13] Water quality that is suitable for Anisus vorticulus is water without turbidity, with a high pH and a low level of nutrients. [1] [13] The main threats to this snail include land drainage, poor habitat management and eutrophication. [13]
The depressed river mussel or compressed river mussel, Pseudanodonta complanata, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. The species name comes from the flattened shape of its shell.
Gyraulus crista, commonly called the Nautilus ramshorn, is a minute species of freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Planorbis planorbis is a species of air-breathing freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ram's horn snails.
Viviparus contectus, common name Lister's river snail, is a species of large, freshwater snail with an operculum and a gill, an aquatic gastropod mollusk in the family Viviparidae, the river snails.
Pisidium tenuilineatum, the fine-lined pea mussel, is a species of very small freshwater bivalve in the family Sphaeriidae.
Anisus spirorbis is a species of small freshwater air-breathing snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Anisus vortex is a species of small freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ram's horn snails and their allies.
Anisus leucostoma is a European species of small air-breathing freshwater snail, an aquatic pulmonate gastropod in the family Planorbidae, the ram's horn snails and their allies.
Anisus septemgyratus is a species of air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Arion obesoductus is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae, the round-back slugs.
Vallonia declivis is a species of very small air-breathing land snail, a terrestrial pulmonate gastropod mollusk in the family Valloniidae.
Planorbis carinatus is species of air-breathing freshwater snail, a pulmonate gastropod mollusk in the family Planorbidae, the ramshorn snails.
Stagnicola fuscus is a species of freshwater snail, an aquatic gastropod mollusk in the family Lymnaeidae, the pond snails.
Physa fontinalis, common name the common bladder snail, is a species of air-breathing freshwater snail, an aquatic gastropod mollusk in the family Physidae. The shells of species in the genus Physa are left-handed or sinistral.
Bithynia transsilvanica is a species of freshwater snail, an aquatic prosobranch gastropod mollusk in the family Bithyniidae.
Gyraulus albus, common name white ramshorn, is a small species of freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Menetus dilatatus is a species of small air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.
Gyraulus chinensis is a species of small freshwater snail, an aquatic pulmonate gastropod mollusk in the family Planorbidae, the ram's horn snails.