Bigeye thresher vs Red-breasted Merganser

Alopias pelagicus compared with Mergus serrator

Key Differences

• Bigeye thresher is Endangered while Red-breasted Merganser is Least Concern.

Taxonomic Classification

Rank	Bigeye thresher	Red-breasted Merganser
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Aves (Birds)
Order	Lamniformes (Mackerel Sharks)	Anseriformes (Anseriformes)
Family	Alopiidae	Anatidae
Genus	Alopias	Mergus
Species	Alopias pelagicus	Mergus serrator

Evolutionary Relationship

Bigeye thresher and Red-breasted Merganser share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Bigeye thresher

EN — Endangered

Red-breasted Merganser

LC — Least Concern

Physical Characteristics

Attribute	Bigeye thresher	Red-breasted Merganser
Diet	—	—
Average Lifespan	—	—
Average Length	—	—
Average Weight	—	—

Habitat & Geographic Range

Bigeye thresher

Habitat

Typically found in marine environments from coastal waters to deep ocean.

Range

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

Red-breasted Merganser

Habitat

Typically found in various aerial, terrestrial, and aquatic environments.

Range

Widely distributed across Asia (Taiwan), Europe (5 countries), North America (United States), and South America (Colombia).

Bigeye thresher

The Bigeye thresher (Alopias pelagicus) is a species in the genus Alopias. It is currently classified as Endangered on the IUCN Red List. Typically found in marine environments from coastal waters to deep ocean.

Red-breasted Merganser

Red-breasted Merganser (Mergus serrator) is classified as Least Concern (LC) on the IUCN Red List. Widespread and abundant across its range, with stable populations and no immediate conservation concerns.

Shared Countries

Both species can be found in 2 countries:

🇨🇴 Colombia 🇹🇼 Taiwan