Black Bent vs Common Nut Clam

Agrostis gigantea compared with Nuculana pernula

Key Differences

• Black Bent is Least Concern while Common Nut Clam is Vulnerable.

Taxonomic Classification

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

Conservation Status

Black Bent

LC — Least Concern

Common Nut Clam

VU — Vulnerable

Physical Characteristics

Attribute	Black Bent	Common Nut Clam
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Black Bent

Habitat

Inhabits tropical and subtropical moist broadleaf forests within the Neotropic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Africa (South Africa), Asia (Japan), Europe (11 countries), North America (4 countries), Oceania and the Pacific (Australia), and South America (5 countries).

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.

Black Bent

The Black Bent (Agrostis gigantea) is a species in the genus Agrostis. It is currently classified as Least Concern on the IUCN Red List. Inhabits tropical and subtropical moist broadleaf forests within the Neotropic biogeographic realm. Populations are also found in montane and highland environments at higher elevations.

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.

Shared Countries

Both species can be found in 3 countries:

🇩🇰 Denmark 🇳🇴 Norway 🇸🇪 Sweden