Coastal Mushoom vs common freshwater nerite

Agaricus litoralis compared with Theodoxus fluviatilis

Taxonomic Classification

Rank	Coastal Mushoom	common freshwater nerite
Kingdom	Fungi (Fungi)	Animalia (Animals)
Phylum	Basidiomycota (Club Fungi)	Mollusca (Mollusks)
Class	Agaricomycetes (Mushrooms)	Gastropoda (Gastropoda)
Order	Agaricales (Gilled Mushrooms)	Cycloneritida (Cycloneritida)
Family	Agaricaceae (Agarics)	Neritidae
Genus	Agaricus (Button Mushrooms)	Theodoxus
Species	Agaricus litoralis	Theodoxus fluviatilis

Conservation Status

Coastal Mushoom

LC — Least Concern

common freshwater nerite

LC — Least Concern

Physical Characteristics

Attribute	Coastal Mushoom	common freshwater nerite
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Coastal Mushoom

Habitat

Typically found in forest floors, decomposing wood, and soil ecosystems.

Range

Distributed across Belgium, Denmark, Norway, and Sweden.

common freshwater nerite

Habitat

Typically found in terrestrial and aquatic habitats including forests and freshwater.

Range

Found across Europe (11 countries).

Coastal Mushoom

Agaricus litoralis, the coastal mushroom, is a saprotrophic agaric fungus in the family Agaricaceae occurring in sand dunes, coastal grassland, and sandy soil habitats along the coasts of northwestern Europe, with confirmed records from Belgium, Denmark, Norway, and Sweden. The genus Agaricus contains the familiar cultivated button mushroom (A. bisporus) along with hundreds of wild species, and members are characterized by a ring on the stem and browning, discoloring, or non-discoloring flesh when cut, features used in field identification. Agaricus litoralis is a medium-sized mushroom producing white to cream-colored caps 4–10 centimeters across with pinkish then dark brown gills and a stout stem with a double ring, fruiting in sand dune hollows and the grassy margins of coastal habitats from summer through autumn. The specific epithet litoralis refers directly to its coastal habitat preference. As a saprotroph, it decomposes organic matter in the sandy soil substrate, releasing nutrients back into the ecosystem. The species is classified as Least Concern by the IUCN, being relatively widespread in suitable coastal sandy habitat across northwestern Europe. Like many coastal fungi, it is specifically adapted to the nutrient-poor, well-drained, alkaline conditions of stabilized sand dune systems.

common freshwater nerite

<em>Theodoxus fluviatilis</em>, commonly known as the common freshwater nerite, is a small aquatic gastropod mollusc belonging to the family Neritidae. This species is widely distributed across Europe, with documented occurrences in Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Hungary, Latvia, Norway, and Sweden. It typically inhabits freshwater environments, including rivers, streams, and lakes, where it grazes on algae and biofilm on hard substrates such as rocks and submerged wood. The common freshwater nerite is assessed as Least Concern on conservation metrics, reflecting its broad distribution and relatively stable populations across much of its European range. Biological traits of this species remain poorly documented in the scientific literature. <em>Theodoxus fluviatilis</em> plays an ecological role as a grazer in freshwater benthic communities, contributing to the regulation of algal growth on hard surfaces. The species typically favors clean, well-oxygenated waters and can serve as an indicator of water quality in freshwater systems. Its distinctive small, dome-shaped shell with variable patterning makes it recognizable among freshwater invertebrates.