True tunas facts for kids

Quick facts for kids True tunas Temporal range: Tertiary–holocene PreЄ Є O S D C P T J K Pg N
Yellowfin tuna
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Scombriformes
Family:	Scombridae
Tribe:	Thunnini
Genus:	Thunnus South, 1845
Type species
Scomber thynnus Linnaeus, 1758
Subgenus
T. (Thunnus) (bluefin group) T. (Neothunnus) (yellowfin group)
Synonyms
Albacora Jordan, 1888 Germo Jordan, 1888 Thynnus Aguilera, 2020 Kishinoella Jordan & Hubbs, 1925 Neothunnus Kishinouye, 1923 Orcynus Cuvier, 1816 Parathunnus Kishinouye, 1923 Semathunnus Fowler, 1933

Thunnus is a group of amazing ocean fish. They are part of the mackerel family, called Scombridae. These fish are also known as true tunas or real tunas. There are eight different kinds of Thunnus tuna. They are split into two main groups.

These tunas have cool coloring. Their backs are metallic blue, and their bellies are shiny silver-white. This helps them hide from other animals. From above, they blend with the deep blue water. From below, they blend with the bright surface.

Some tunas, like the Atlantic bluefin tuna, can get very big. They can grow up to 15 feet (4.6 m) long. They can also weigh as much as 1,500 pounds (680 kg). All tunas are super fast swimmers. The yellowfin tuna can swim up to 50 miles per hour (80 km/h) when chasing food!

What's special about Thunnus tunas is that they are warm-blooded. Most fish are cold-blooded. Being warm-blooded helps tunas live in cold water. It also lets them dive very deep. For example, bluefin tunas live in cold places like Newfoundland and Iceland. But they also go to warm places like the Gulf of Mexico and the Mediterranean Sea to lay their eggs.

Sadly, too many of these fish have been caught. This is called overfishing. Because of this, Thunnus tunas are not found in as many places as before. For instance, they have almost disappeared from the Black Sea.

What's in a Name?

The name Thunnus comes from an old Latin word. That word came from the Greek word thýnnos. It means "tuna" or "to rush" or "to dart." The famous writer Homer was the first to use this word a long time ago.

True Tuna Families

Scientists group Thunnus tunas into two main families, or subgenera. These are Thunnus (Thunnus) and Thunnus (Neothunnus).

• Thunnus (Thunnus) is known as the bluefin group.
• Thunnus (Neothunnus) is known as the yellowfin group.

Scientists used to sort tunas by looking at their bodies. They also looked at tiny bits of their DNA. But new studies using different DNA have changed some ideas. These studies suggest that some tunas might be grouped differently. For example, some think the Bigeye Tuna might belong with the yellowfin group instead of the bluefin group.

A fossil of a Thunnus tuna.

This group of tunas has eight different kinds, split into two main families:

• Subgenus Thunnus (Thunnus) (the bluefin group):
  • Albacore, T. alalunga
  • Southern bluefin tuna, T. maccoyii
  • Bigeye tuna, T. obesus
  • Pacific bluefin tuna, T. orientalis
  • Atlantic bluefin tuna, T. thynnus
• Subgenus Thunnus (Neothunnus) (the yellowfin group):
  • Yellowfin tuna, T. albacares
  • Blackfin tuna, T. atlanticus
  • Longtail tuna, T. tonggol

Relative sizes of different tunas. The Atlantic bluefin tuna (top) is about 8 ft (2.4 m) in this picture.

Different Kinds of True Tunas

For a long time, people thought there were seven types of Thunnus tuna. They also thought that Atlantic bluefin tuna and Pacific bluefin tuna were just different versions of the same fish. But in 1999, a scientist named Collette showed they are actually different kinds of fish. He looked at their bodies and their DNA to figure this out.

Thunnus, the true tunas
Image	Common name	Scientific name	Maximum length	Common length	Maximum weight	Maximum age	Trophic level	Source	IUCN status
Thunnus (Thunnus) – the bluefin group
	Albacore tuna	T. alalunga (Bonnaterre, 1788)	1.4 m (4.6 ft)	1.0 m (3.3 ft)	60.3 kg (133 lb)	9–13 yrs	4.31		Least Concern
	Southern bluefin tuna	T. maccoyii (Castelnau, 1872)	2.45 m (8.0 ft)	1.6 m (5.2 ft)	260 kg (570 lb)	20–40 yrs	3.93		Endangered
	Bigeye tuna	T. obesus (Lowe, 1839)	2.5 m (8.2 ft)	1.8 m (5.9 ft)	210 kg (460 lb)	5–16 yrs	4.49		Vulnerable
	Pacific bluefin tuna	T. orientalis (Temminck & Schlegel, 1844)	3.0 m (9.8 ft)	2.0 m (6.6 ft)	450 kg (990 lb)	15–26 yrs	4.21		Near Threatened
	Atlantic bluefin tuna	T. thynnus (Linnaeus, 1758)	4.6 m (15 ft)	2.0 m (6.6 ft)	684 kg (1,508 lb)	35–50 yrs	4.43		Least Concern
Thunnus (Neothunnus) – the yellowfin group
	Blackfin tuna	T. atlanticus (Lesson, 1831)	1.1 m (3.6 ft)	0.7 m (2.3 ft)	22.4 kg (49 lb)		4.13		Least concern
	Longtail tuna, northern bluefin tuna, tongol tuna	T. tonggol (Bleeker, 1851)	1.45 m (4.8 ft)	0.7 m (2.3 ft)	35.9 kg (79 lb)	18 years	4.50		Data deficient
	Yellowfin tuna	T. albacares (Bonnaterre, 1788)	2.4 m (7.9 ft)	1.5 m (4.9 ft)	200 kg (440 lb)	5–9 yrs	4.34		Least Concern

This chart shows the biggest sizes recorded for different kinds of Thunnus tunas.

Why Tunas Need Our Help

People around the world love to eat tuna, especially in dishes like sushi and sashimi. More and more people are eating tuna. This has led to too many tunas being caught. This is called overfishing. Bluefin tuna is especially at risk. It is a serious concern for people who work to protect animals.

It's hard to manage tuna fishing because these fish travel very far. They swim across huge parts of the ocean. These areas are not owned by any one country. So, fishing boats from many countries can catch them. This makes it hard to agree on rules and make sure everyone follows them.

Some countries, like Japan and Australia, have tried to farm tuna. This means raising them in special pens. But tuna grow very slowly. This makes it harder to farm them than other fish. So, farmed tuna is still very expensive. For example, in 2012, a huge bluefin tuna weighing 222-kilogram (489 lb) was sold for a record $1.76 million in Tokyo!

See also

In Spanish: Thunnus para niños