Tuna - worldwide distribution

It is thought freshwater eels were originally marine fish which adapted to live most of their lives in fresh water, and that the present distribution of the 18 species of freshwater eel is largely a result of continental drift.

 

Kingdom:                          

Animalia                           

Phylum:

Chordata

Class:

Actinopterygii

Subclass:

Neopterygii

Order:

Anguilliformes

Suborder:

Anguilloidei

Family:

Anguillidae

Genus:

Anguilla

 

Anguilliformes are the order of fish that contain eels. Eels are distributed worldwide, and there are 720 species of 'true eels', or Anguilliformes. Almost all of these species are marine: for example, there are over 130 species of conger eels, 170 of moray eels, and 250 of worm (or snake) eels.

Anguillidae is the family of fish that contains the majority of the freshwater eels. There are currently 18 recognised freshwater eels (Anguilla) species/subspecies worldwide, distributed in both tropical (around the equator) and temperate (between the tropics and polar circles) zones, with some species overlapping between these two zones.

Recent studies indicate that tropical eels make much shorter migrations (100's of km) to spawn in areas near their freshwater habitats, compared to the long distances travelled by temperate eels (1000's of km).

 

Table: Geographic ranges of freshwater eel species from around the world.

Zone

 

Species

 

Geographical distribution

 

Mottled skin?

 

Tropical A. marmorata Indo-Pacific: Indian Ocean to Polynesia

 

Yes

 

 

 

A. bicolor Indo-Pacific: Indian Ocean to Papua New Guinea

 

No

 

 

 

A. celebesensis Tropical Pacific: Indonesia, South China Sea

 

Yes

 

 

 

A. borneensis Tropical Pacific: Indonesia, South China Sea

 

No

 

 

 

A. nebulosa Indo-Pacific: Indian Ocean

 

Yes

 

 

 

A. mossambica Indo-Atlantic: Indian Ocean

 

No

 

 

 

A. megastoma Tropical-Pacific: New Guinea to Polynesia

 

Yes

 

 

 

A. obscura Indo-Pacific: New Guinea to Polynesia

 

No

 

 

A. reinhardtii

(Australian longfin)

Australia, New Caledonia to North Island of New Zealand

Yes

 

 

 


 

 

 

 

Temperate A. anguilla Indo-Atlantic: Europe, North Africa, Mediterranean, Iceland

 

No

 

 

 

A. rostrata Indo-Atlantic: East coast of North, Central and South America, Greenland

 

No

 

 

 

A. japonica China and Japan

 

No

 

 

 

A. australis
(Shortfin)
Oceania: Australia and New Zealand

 

No

 

 

 

A. dieffenbachii
(New Zealand longfin)

Oceania: New Zealand, Chatham and Auckland Islands

No

 

 

References and further reading

Aoyama, J. (2009). Life history and evolution of migration in catadromous eels (Genus Anguilla). Aqua-BioScience Monographs 2(1): 1-42. http://www.terrapub.co.jp/onlinemonographs/absm/abstract/02/0201.html

Jellyman, D.J. (2003). The distribution and biology of the South Pacific species of Anguilla. In: Aida, K., Tsukamoto, K., Yamauchi, K (Eds). Eel Biology. Springer, Tokyo. pp. 275-292. http://www.springer.com/life+sciences/animal+sciences/book/978-4-431-00458-5

Tesch, F.W. (2003). The Eel. Fifth edition. Blackwell Science Ltd and The Fisheries Society of the British Isles, Oxford. 408 p.

Australian “speckled or spotted” longfin eel. Five of the world’s 18 different freshwater eel species have mottled skin. Credit: Ben Chisnall
Worldwide distribution of freshwater eels, shown as thick black lines. No freshwater eels are found in the South Atlantic, eastern Pacific or the polar regions. Credit: Aoyama (2009)
Unidentified marine eel photographed during a biodiversity survey of the Chatham Rise. Credit: NIWA