Common Nut Clam vs Common Silver Hairgrass

Nuculana pernula compared with Aira caryophyllea

Key Differences

• Common Nut Clam is Vulnerable while Common Silver Hairgrass is Endangered.

Taxonomic Classification

Rank	Common Nut Clam	Common Silver Hairgrass
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Mollusca (Mollusks)	Magnoliophyta (Flowering Plants)
Class	Bivalvia (Bivalvia)	Liliopsida (Monocots)
Order	Nuculanida (Nuculanida)	Poales (Grasses)
Family	Nuculanidae	Poaceae (Grass Family)
Genus	Nuculana	Aira
Species	Nuculana pernula	Aira caryophyllea

Conservation Status

Common Nut Clam

VU — Vulnerable

Common Silver Hairgrass

EN — Endangered

Physical Characteristics

Attribute	Common Nut Clam	Common Silver Hairgrass
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common Nut Clam

Habitat

Native to Europe, inhabiting ecosystems characteristic of the region.

Range

Distributed across Denmark, Norway, and Sweden. Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Silver Hairgrass

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical grasslands and savannas, and flooded grasslands and savannas, among 11 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (Cameroon), Asia (Japan, South Korea), Europe (6 countries), North America (4 countries), Oceania and the Pacific (Australia), and South America (4 countries). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Common Nut Clam

<em>Nuculana pernula</em>, sometimes referred to as a nut clam, is a small marine bivalve mollusk in the family Nuculanidae, part of the subclass Protobranchia. Like other protobranchs, <em>Nuculana pernula</em> is a deposit feeder that typically burrows into fine-grained marine sediments, using its palp proboscides to gather organic detritus and microorganisms from surface sediment layers. It typically inhabits subtidal and deep-water soft-bottom habitats along cold-temperate and boreal Atlantic coasts, with documented occurrences in Denmark, Norway, and Sweden. The species is currently assessed as Vulnerable by the IUCN, indicating that it faces a higher level of extinction risk than related species, potentially reflecting sensitivity to habitat degradation, bottom trawling disturbance, and shifts in sediment quality. Biological traits such as lifespan, body size, and diet remain poorly documented at a standardized population level for this species. <em>Nuculana pernula</em> contributes to benthic ecosystem function through sediment bioturbation and organic matter processing, and its Vulnerable status highlights the importance of protecting deep-sea and subtidal soft-sediment habitats from physical disturbance.

Common Silver Hairgrass

<em>Aira caryophyllea</em>, commonly known as Common Silver Hairgrass, is a slender annual grass belonging to the family Poaceae within the order Poales. This delicate grass is currently classified as Endangered on the IUCN Red List, reflecting significant conservation concern despite its historically broad distribution. It is typically found across a remarkable diversity of biome types, including tropical and subtropical moist broadleaf forests, grasslands, savannas, and flooded habitats, demonstrating notable ecological versatility. Its geographic range spans multiple continents, with documented populations in Africa (Cameroon), Asia (Japan, South Korea), Europe, North America, Australia, and South America. As an annual grass, it completes its life cycle within a single growing season, reproducing via wind-dispersed seeds. The inflorescence typically bears silvery, shimmering spikelets that give the species its common name. Biological traits such as average lifespan, body dimensions, and dietary specifics follow typical patterns for annual grasses — drawing nutrients from soil through root absorption rather than consuming other organisms. The endangered status suggests populations may be declining due to habitat loss, land-use change, or invasive species pressure across parts of its range.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden