Basking shark vs Big Finner

Rhincodon typus compared with Balaenoptera physalus

Taxonomic Classification

Rank	Basking shark	Big Finner
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Mammalia (Mammals)
Order	Lamniformes (Mackerel Sharks)	Cetacea (Whales & Dolphins)
Family	Rhincodontidae (Whale Sharks)	Balaenopteridae (Rorquals)
Genus	Rhincodon (Whale Sharks)	Balaenoptera (Rorquals)
Species	Rhincodon typus	Balaenoptera physalus

Evolutionary Relationship

Basking shark and Big Finner share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Basking shark

EN — Endangered

Trend: Decreasing ↓

Big Finner

EN — Endangered

Physical Characteristics

Attribute	Basking shark	Big Finner
Diet	Omnivore	—
Average Lifespan	100 years	—
Average Length	12.0 m	—
Average Weight	20.0 t	—

Habitat & Geographic Range

Basking shark

Habitat

Found across multiple habitat types including temperate broadleaf and mixed forests, temperate grasslands and steppes, and montane grasslands and shrublands, among 5 distinct biome types within the Neotropic biogeographic realm.

Range

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

Big Finner

Habitat

Found across multiple habitat types including tropical and subtropical dry broadleaf forests, flooded grasslands and savannas, and montane grasslands and shrublands, among 4 distinct biome types within the Neotropic biogeographic realm.

Range

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

Basking shark

The world's largest fish, whale sharks can exceed 12 meters and 20 tonnes, inhabiting tropical and warm temperate oceans worldwide. Despite their massive size, they are harmless filter feeders, consuming plankton, fish eggs, and small fish by swimming open-mouthed through prey-dense water. They undertake vast seasonal migrations following plankton blooms. Endangered due to fishing, boat strikes, and the live fin trade, with population declining by approximately 50% over the past 75 years.

Big Finner

Big Finner (Balaenoptera physalus) is classified as Endangered (EN) on the IUCN Red List. At high risk of extinction in the wild, with significant population decline and ongoing threats to survival.

Shared Countries

Both species can be found in 3 countries:

🇵🇹 Portugal 🇹🇼 Taiwan 🇻🇪 Venezuela