Overview

Cow and sevengill sharks are unmistakable once you notice the one dorsal fin and extra gill slits. This family profile fits sharks that feel ancient in outline: broad-headed, powerful, and often tied to deeper water. Hexanchids are easy to separate from most modern sharks because they have only one dorsal fin and six or seven gill slits instead of the usual five. Cow and sevengill sharks occur in many temperate and tropical seas around the world. Some species range from continental shelves into very deep offshore waters, while others are more coastal.

The family spans cold deep basins, fjords, shelf edges, and shallow coastal embayments, depending on species.

Added from the World Register of Marine Species (WoRMS).

Why it matters: Their extra gill slits make them look like a throwback to older shark lineages.

Common namebigeye sixgill shark
Scientific nameHexanchus nakamurai
FamilyHexanchidae
OrderHexanchiformes
Max length1.8 m
Depth range0 to 0 meters
RegionNorth Atlantic Ocean, European waters, Mozambique
DietData not available in this offline release.
HabitatMarine waters (habitat data not available locally).
Why it stands outFamily: Hexanchidae

What this shark is

Hexanchids are easy to separate from most modern sharks because they have only one dorsal fin and six or seven gill slits instead of the usual five.

Where it lives

Cow and sevengill sharks occur in many temperate and tropical seas around the world. Some species range from continental shelves into very deep offshore waters, while others are more coastal.

The family spans cold deep basins, fjords, shelf edges, and shallow coastal embayments, depending on species.

How it differs from similar sharks

Family: Hexanchidae

Compare it against bluntnose sixgill shark, sixgill shark, and broadnose sevengill shark.

Why it is notable

Direct encounters with people are uncommon outside a few coastal species and dive sites. Fisheries bycatch and local depletion are bigger issues than ordinary contact.

Species-level taxonomy was verified from Sharkipedia's current species list and taxonomy workbook. In this pass, the narrative fields are cautious family-level placeholders synthesized from broad shark references, chiefly the FAO Sharks of the World catalogue, because a stronger multi-source species-level synthesis was not assembled here without risking invented detail. Replace this with a direct species-level synthesis before publication in the app.

Related shark pages

These links are meant to help readers continue through related species, not force extra clicks.