Common harp ground beetle vs Compact Stonewort

Amara communis compared with Nitella tenuissima

Key Differences

• Common harp ground beetle is Least Concern while Compact Stonewort is Extinct.

Taxonomic Classification

Rank	Common harp ground beetle	Compact Stonewort
Kingdom	Animalia (Animals)	Plantae (Plants)
Phylum	Arthropoda (Arthropods)	Charophyta (Charophyta)
Class	Insecta (Insects)	Charophyceae (Charophyceae)
Order	Coleoptera (Beetles)	Charales (Charales)
Family	Carabidae	Characeae
Genus	Amara	Nitella
Species	Amara communis	Nitella tenuissima

Conservation Status

Common harp ground beetle

LC — Least Concern

Compact Stonewort

EX — Extinct

Physical Characteristics

Attribute	Common harp ground beetle	Compact Stonewort
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Common harp ground beetle

Habitat

Typically found in virtually all terrestrial and freshwater habitats.

Range

Found across Europe (5 countries) and North America (Canada, United States).

Compact Stonewort

Habitat

Native to Asia and Europe and North America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Brazil, Norway, Sweden, Taiwan, and United States.

Common harp ground beetle

The common harp ground beetle, <em>Amara communis</em>, is an insect belonging to the order Coleoptera, family Carabidae, the ground beetles. This species is distributed across Europe and North America, indicating a wide Holarctic range. Ground beetles of the genus Amara are typically found in a variety of terrestrial habitats including grasslands, agricultural fields, woodland margins, and disturbed areas. Members of this genus are generally omnivorous or seed-feeding, and some are known to consume weed seeds, giving them potential ecological significance in agroecosystems. <em>Amara communis</em> is assessed as Least Concern on the IUCN Red List, reflecting stable populations across its range. No dietary information has been provided specifically for this species in current records. Biological traits of this species remain poorly documented in the scientific literature.

Compact Stonewort

<em>Nitella tenuissima</em>, a stonewort formerly found in fresh and brackish water habitats, was a member of the charophyte family Characeae — the algal lineage most closely related to land plants. Historical records document its occurrence across Brazil, Norway, Sweden, Taiwan, and the United States, where it inhabited clear, oligotrophic lakes, ponds, and slow-flowing water bodies with low nutrient levels. Like other Nitella species, it was a delicate, translucent, submerged aquatic plant lacking the calcium carbonate encrustation of related genera, forming low-growing mats on soft sediments in well-illuminated shallow water. The species played a role in aquatic ecosystems by stabilising lake sediments, contributing to water clarity, and providing microhabitat for invertebrates and small aquatic organisms. <em>Nitella tenuissima</em> is classified as Extinct by the IUCN, having not been recorded from any of its former localities despite targeted searches. The primary causes of its extinction are believed to be widespread eutrophication of freshwater habitats driven by agricultural nutrient runoff and sewage discharge, which eliminated the clear, nutrient-poor conditions on which the species depended. The loss of this stonewort is emblematic of the broader decline of freshwater charophyte diversity across the Northern Hemisphere. Biological traits including historical morphological measurements and reproductive parameters are documented only in sparse historical herbarium specimens and early botanical literature.

Shared Countries

Both species can be found in 3 countries:

🇳🇴 Norway 🇸🇪 Sweden 🇺🇸 United States