ハクトウワシ vs Common Water-Nymph

Haliaeetus leucocephalus compared with Najas guadalupensis

Taxonomic Classification

Rank	ハクトウワシ	Common Water-Nymph
Kingdom	Animalia (動物)	Plantae (植物)
Phylum	Chordata (脊索動物)	Magnoliophyta (被子植物門)
Class	Aves (鳥類)	Liliopsida (単子葉植物綱)
Order	Accipitriformes (タカ目)	Alismatales (オモダカ目)
Family	Accipitridae (Hawks & Eagles)	Hydrocharitaceae
Genus	Haliaeetus (Sea Eagles)	Najas
Species	Haliaeetus leucocephalus	Najas guadalupensis

Conservation Status

ハクトウワシ

NE — Not Evaluated

Population: ~316.7K

Trend: Increasing ↑

Common Water-Nymph

NE — Not Evaluated

Physical Characteristics

Attribute	ハクトウワシ	Common Water-Nymph
Diet	Carnivore	—
Average Lifespan	28 years	—
Average Length	90 cm	—
Average Weight	5.0 kg	—

Habitat & Geographic Range

ハクトウワシ

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and flooded grasslands and savannas, among 10 distinct biome types spanning the Neotropic and Palearctic realms. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Europe (8 countries), North America (United States), and South America (Ecuador).

Common Water-Nymph

Habitat

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

Range

Widely distributed across Asia (Israel, Taiwan), Europe (4 countries), North America (4 countries), and South America (Brazil, Colombia).

ハクトウワシ

アメリカの国鳥であり保全の成功を象徴するハクトウワシは翼開長が最大2.4 mに達し、北米全域の水辺近くの森林や湿地に生息する。強力な空中捕食者兼腐肉食者で魚を主食とするが、水鳥や腐肉も捕食する。DDT汚染と狩猟によって1960年代にほぼ絶滅に瀕したが、農薬の使用禁止と絶滅危惧種法の施行により劇的に回復した。

Common Water-Nymph

<em>Najas guadalupensis</em>, commonly known as the common water nymph or southern naiad, is a submerged aquatic plant in the family Hydrocharitaceae. Its conservation status is listed as Not Evaluated by the IUCN. The species has an extensive distribution spanning Asia, Europe, and the Americas, where it inhabits a wide range of lentic and lotic freshwater environments including ponds, lakes, slow streams, and irrigation channels. It typically grows fully submerged, rooting in sandy or muddy substrates in water ranging from shallow margins to depths exceeding two meters. The plant is slender and branching, with narrow, finely toothed leaves arranged oppositely or in whorls along the stem. <em>Najas guadalupensis</em> is adapted to a range of water quality conditions and can persist in turbid, nutrient-enriched environments where other aquatic macrophytes cannot. It typically reproduces through both seed and fragmentation, with stem fragments readily establishing new colonies. Pollination occurs underwater, with pollen dispersed directly through the water column. Biological traits including average lifespan, stem length, and mass remain poorly documented in standardized databases. Ecologically, common water nymph provides important submerged habitat structure for fish, invertebrates, and waterfowl, offering spawning substrate, foraging areas, and refuge from predators in the diverse freshwater systems it occupies throughout its broad geographic range.