Clustered Stonewort vs Hooded seal

Tolypella glomerata compared with Cystophora cristata

Key Differences

Clustered Stonewort is Vulnerable while Hooded seal is Endangered.

Taxonomic Classification

Rank	Clustered Stonewort	Hooded seal
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Charophyta (Charophyta)	Chordata (Chordates)
Class	Charophyceae (Charophyceae)	Mammalia (Mammals)
Order	Charales (Charales)	Pinnipedia (Seals & Sea Lions)
Family	Characeae	Phocidae (True Seals)
Genus	Tolypella	Cystophora
Species	Tolypella glomerata	Cystophora cristata

Conservation Status

Clustered Stonewort

VU — Vulnerable

Hooded seal

EN — Endangered

Physical Characteristics

Attribute	Clustered Stonewort	Hooded seal
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Clustered Stonewort

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.

Hooded seal

Habitat

Typically found in diverse terrestrial and aquatic ecosystems.

Range

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

Clustered Stonewort

Tolypella glomerata, the clustered stonewort, is a charophyte alga in the family Characeae, found in calcareous, nutrient-poor freshwater habitats including lakes, ponds, ditches, and slow-flowing water in northwestern and northern Europe. Charophytes are macroscopic green algae with a distinctive whorl-like arrangement of branches and a complex, plant-like structure that distinguishes them from other algae. T. glomerata is encrusted with calcium carbonate deposits (hence 'stonewort'), giving it a pale, grey-green appearance and rough texture. The species colonizes clear, low-nutrient water over fine sediment or gravel substrates where competition from vascular plants is reduced by nutrient limitation. It is listed as Vulnerable by the IUCN, reflecting significant declines driven by eutrophication (nutrient enrichment from agriculture and sewage), which promotes the growth of vascular plants and phytoplankton that shade out stoneworts. Drainage, water abstraction, and peat cutting also threaten its habitats. Charophyte diversity has declined substantially across lowland Europe and North America over the past century, with many species becoming locally extinct from sites they once colonized.