common freshwater nerite vs koala

Theodoxus fluviatilis compared with Phascolarctos cinereus

Key Differences

• common freshwater nerite is Least Concern while koala is Vulnerable.

Taxonomic Classification

Rank	common freshwater nerite	koala
Kingdom same	Animalia (动物界)	Animalia (动物界)
Phylum	Mollusca (软体动物门)	Chordata (脊索动物门)
Class	Gastropoda (腹足纲)	Mammalia (哺乳動物)
Order	Cycloneritida (Cycloneritida)	Diprotodontia (雙門齒目)
Family	Neritidae	Phascolarctidae (Koalas)
Genus	Theodoxus	Phascolarctos (Koalas)
Species	Theodoxus fluviatilis	Phascolarctos cinereus

Evolutionary Relationship

common freshwater nerite and koala share a common ancestor at the Kingdom level: Animalia. (动物界)

Conservation Status

common freshwater nerite

LC — Least Concern

koala

VU — Vulnerable

Population: ~100.0K

Trend: Decreasing ↓

Physical Characteristics

Attribute	common freshwater nerite	koala
Diet	—	Herbivore
Average Lifespan	—	15 years
Average Length	—	75 cm
Average Weight	—	10.0 kg

Habitat & Geographic Range

common freshwater nerite

Habitat

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

Range

Found across Europe (11 countries).

koala

Habitat

Typically found in grasslands, forests, and vegetated habitats.

Range

Found in Australia. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

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.

koala

澳大利亚东部和东南部的标志性有袋类动物，体重最大可达15千克，为了节省低热量桉树叶食物所提供的能量，每天最多睡眠22小时。高度特化，能够处理会致大多数其他哺乳动物死亡的有毒桉树成分，拥有专门适应解毒功能的肠道微生物群。因衣原体病、栖息地开发和气候变化导致种群锐减，2022年被列为濒危物种。