Fish
Atlantic bluefin tuna
Thunnus thynnus
Epipelagic zone · Mesopelagic zone
One of the fastest fish in the ocean, able to keep its muscles warmer than the surrounding water to cross the Atlantic during its migrations.
🗺️ Geographic range
The Atlantic Ocean and Mediterranean Sea, with distinct populations migrating between spawning and feeding grounds.
📊 Population
After being listed as "endangered" in the 2010s, the Atlantic population recovered enough for the IUCN to reclassify the species as least concern in 2021 — one of the rare success stories of large-scale fisheries management.
Habitat
- Atlantic Ocean · High seas / open water · Epipelagic zone · Migration
- Mediterranean Sea · High seas / open water · Epipelagic zone · Migration
🥚 Reproduction
Spawns in warm water, laying clutches that can reach several million eggs.
Behaviour
- Diet
- Herring, mackerel, squid and occasionally lanternfish during deep dives.
- Hunting
- Hunts in high-speed groups, encircling schools of small fish.
- Communication
- Limited; group coordination during hunts is mostly visual.
- Social life
- Gregarious, undertakes transatlantic migrations of thousands of kilometres.
Physiology
- Anatomy
- A streamlined, hydrodynamic body with retractable fins to reduce drag.
- Respiration
- Continuous gill ventilation; never stops swimming.
- Vision
- Good eyesight suited to hunting in open water.
- Adaptations
- Regional endothermy: warms its muscles, eyes and brain above water temperature, rare among fish.
🔗 Web of marine life
⚡ Its extraordinary abilities
- Can keep its muscle temperature above that of the surrounding water (regional endothermy)
- Top speed among the highest of all bony fish
🏆 Records
Among the highest auction prices ever paid for a fish
A single specimen sold for several hundred thousand euros at the Tokyo fish market.
Source: Ifremer
If you cross paths with this animal…
Risk: No danger to humans.
Behaviour: Wary, naturally avoids divers.
Advice: A historically overfished species: choose certified sustainably-sourced tuna.
💡 Did you know?
- Can cross the entire Atlantic Ocean during its annual migrations.
- A single specimen once sold at a Tokyo auction for several hundred thousand euros.
