Common hammerhead vs European otter

Sphyrna zygaena compared with Lutra lutra

Key Differences

• Common hammerhead is Not Evaluated while European otter is Vulnerable.

Taxonomic Classification

Rank	Common hammerhead	European otter
Kingdom same	Animalia (Animals)	Animalia (Animals)
Phylum same	Chordata (Chordates)	Chordata (Chordates)
Class	Chondrichthyes (Cartilaginous Fish)	Mammalia (Mammals)
Order	Carcharhiniformes (Ground Sharks)	Carnivora (Carnivorans)
Family	Sphyrnidae (Hammerhead Sharks)	Mustelidae (Weasels & Otters)
Genus	Sphyrna (Hammerhead Sharks)	Lutra (Otters)
Species	Sphyrna zygaena	Lutra lutra

Evolutionary Relationship

Common hammerhead and European otter share a common ancestor at the Phylum level: Chordata. (Chordates)

Conservation Status

Common hammerhead

NE — Not Evaluated

European otter

VU — Vulnerable

Trend: Stable →

Physical Characteristics

Attribute	Common hammerhead	European otter
Diet	—	Carnivore
Average Lifespan	—	10 years
Average Length	—	1.0 m
Average Weight	—	10.0 kg

Habitat & Geographic Range

Common hammerhead

Habitat

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

Range

Distributed across Chile, Denmark, Portugal, Sweden, and Taiwan.

European otter

Habitat

Typically found in diverse ecosystems where prey species are available.

Range

Found across Europe (6 countries). Currently classified as Vulnerable on the IUCN Red List, this species faces significant conservation challenges across its range.

Common hammerhead

The common hammerhead, <em>Sphyrna zygaena</em>, is a cartilaginous fish belonging to the order Carcharhiniformes, family Sphyrnidae. This species is typically found in marine environments and has a distribution that includes the waters of Chile, Denmark, Portugal, Sweden, and Taiwan, reflecting a wide range across both Atlantic and Pacific Ocean systems. As a hammerhead shark, <em>Sphyrna zygaena</em> possesses the characteristic cephalofoil, the laterally expanded head structure that provides enhanced sensory capabilities and hydrodynamic benefits. Hammerhead sharks are generally known to be active, wide-ranging predators within marine ecosystems. No dietary information has been provided for this specific species in current records. Biological traits of this species remain poorly documented in the scientific literature.

European otter

Sleek semi-aquatic mustelid found along clean rivers, streams, and coastlines across Europe and Asia. European otters can reach 1.3 meters in length and are highly skilled fish hunters, using sensitive whiskers to detect prey movements. Requiring unpolluted water with abundant fish, they are an indicator species for freshwater ecosystem health. Once nearly extinct in Western Europe from hunting and pollution, populations have recovered significantly following water quality improvements.

Shared Countries

Both species can be found in 2 countries:

🇩🇰 Denmark 🇸🇪 Sweden