Bigeye Sixgill Shark vs common bottlenose dolphin

Hexanchus nakamurai compared with Tursiops truncatus

Key Differences

• Bigeye Sixgill Shark is Near Threatened while common bottlenose dolphin is Least Concern.

Taxonomic Classification

Rank	Bigeye Sixgill Shark	common bottlenose dolphin
Kingdom same	Animalia (животные)	Animalia (животные)
Phylum same	Chordata (хордовые)	Chordata (хордовые)
Class	Elasmobranchii	Mammalia (млекопитающие)
Order	Hexanchiformes (многожаберникообразные)	Cetacea (Whales & Dolphins)
Family	Hexanchidae	Delphinidae (Oceanic Dolphins)
Genus	Hexanchus	Tursiops (Bottlenose Dolphins)
Species	Hexanchus nakamurai	Tursiops truncatus

Evolutionary Relationship

Bigeye Sixgill Shark and common bottlenose dolphin share a common ancestor at the Phylum level: Chordata. (хордовые)

Conservation Status

Bigeye Sixgill Shark

NT — Near Threatened

common bottlenose dolphin

LC — Least Concern

Population: ~600.0K

Trend: Stable →

Physical Characteristics

Attribute	Bigeye Sixgill Shark	common bottlenose dolphin
Diet	—	Carnivore
Average Lifespan	—	45 years
Average Length	—	3.0 m
Average Weight	—	300.0 kg

Habitat & Geographic Range

Bigeye Sixgill Shark

Habitat

Native to Asia and South America, inhabiting ecosystems characteristic of the region.

Range

Distributed across Taiwan and Venezuela. Listed as Near Threatened, this species requires ongoing monitoring to prevent population decline.

common bottlenose dolphin

Habitat

Found across multiple habitat types including tropical and subtropical moist broadleaf forests, tropical and subtropical dry broadleaf forests, and tropical and subtropical grasslands and savannas, among 12 distinct biome types. Populations are also found in montane and highland environments at higher elevations.

Range

Widely distributed across Asia (Taiwan), Europe (6 countries), and South America (Colombia, Ecuador, Venezuela).

Bigeye Sixgill Shark

The Bigeye Sixgill Shark (Hexanchus nakamurai) is a species in the genus Hexanchus. It is currently classified as Near Threatened on the IUCN Red List. Native to Asia and South America, inhabiting ecosystems characteristic of the region.

common bottlenose dolphin

The most studied and recognized dolphin species, bottlenose dolphins inhabit warm and temperate oceans worldwide, from coastal shallows to the open sea. Highly intelligent with large brains relative to body size, they demonstrate self-recognition, complex communication, and social learning. They live in fluid fission-fusion societies and cooperate to herd fish. A keystone indicator species for marine ecosystem health.

Shared Countries

Both species can be found in 2 countries:

🇹🇼 Taiwan 🇻🇪 Venezuela