Ricefield waternymph vs Spiny naiad

Najas graminea compared with Najas marina

Key Differences

• Ricefield waternymph is Least Concern while Spiny naiad is Endangered.

Taxonomic Classification

Rank	Ricefield waternymph	Spiny naiad
Kingdom same	Plantae (植物)	Plantae (植物)
Phylum same	Magnoliophyta (被子植物門)	Magnoliophyta (被子植物門)
Class same	Liliopsida (単子葉植物綱)	Liliopsida (単子葉植物綱)
Order same	Alismatales (オモダカ目)	Alismatales (オモダカ目)
Family same	Hydrocharitaceae	Hydrocharitaceae
Genus same	Najas	Najas
Species	Najas graminea	Najas marina

Evolutionary Relationship

Ricefield waternymph and Spiny naiad share a common ancestor at the Genus level: Najas.

Conservation Status

Ricefield waternymph

LC — Least Concern

Spiny naiad

EN — Endangered

Physical Characteristics

Attribute	Ricefield waternymph	Spiny naiad
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Ricefield waternymph

Habitat

Typically found in grasslands, wetlands, forests, and cultivated landscapes.

Range

Widely distributed across Africa (Guinea), Asia (Taiwan), Europe (10 countries), North America (United States), Oceania and the Pacific (Papua New Guinea), and South America (Brazil).

Spiny naiad

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and deserts and xeric shrublands, among 5 distinct biome types spanning the Indomalayan and Neotropic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Sri Lanka, Taiwan), Europe (5 countries), North America (6 countries), and South America (Brazil). Currently classified as Endangered on the IUCN Red List, this species faces significant conservation challenges across its range.

Shared Countries

Both species can be found in 6 countries:

🇧🇪 Belgium 🇧🇷 Brazil 🇫🇷 France 🇳🇴 Norway 🇹🇼 Taiwan 🇺🇸 United States