Compact Stonewort vs Mexican Agouti

Nitella tenuissima compared with Dasyprocta mexicana

Key Differences

• Compact Stonewort is Extinct while Mexican Agouti is Critically Endangered.

Taxonomic Classification

Rank	Compact Stonewort	Mexican Agouti
Kingdom	Plantae (Plants)	Animalia (Animals)
Phylum	Charophyta (Charophyta)	Chordata (Chordates)
Class	Charophyceae (Charophyceae)	Mammalia (Mammals)
Order	Charales (Charales)	Rodentia (Rodents)
Family	Characeae	Dasyproctidae
Genus	Nitella	Dasyprocta
Species	Nitella tenuissima	Dasyprocta mexicana

Conservation Status

Compact Stonewort

EX — Extinct

Mexican Agouti

CR — Critically Endangered

Physical Characteristics

Attribute	Compact Stonewort	Mexican Agouti
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

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.

Mexican Agouti

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical coniferous forests, among 5 distinct biome types within the Neotropic biogeographic realm.

Range

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

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.