Aquarist Atlas · the freshwater eels

Every ‘eel’ on one map

3,852 georeferenced records across 131 species, drawn across most of the warm world — for these “eels” are three unrelated families. The spiny eels (Mastacembelidae) burrow in the rivers and rift lakes of Africa and tropical Asia; the swamp eels (Synbranchidae) breathe air in the paddies, swamps and caves of the Old- and New-World tropics; and the true eels (Anguilla) are near-global wanderers that grow in fresh water but slip back to the sea to spawn. Colour the cloud by group, or switch to compare mode and read two species’ ranges against each other.

© Adobe Stock

About this map. Scroll or pinch to zoom, drag to pan, and click a dot to identify the species. The 3,852 dots are real occurrence records pulled from GBIF, the Global Biodiversity Information Facility — an aggregator of museum specimens, scientific surveys and verified citizen-science sightings — queried for both each fish’s current name and its older genus combination (the African spiny eels in particular were long filed under Aethiomastacembelus and Caecomastacembelus). Treat them as a guide to where a species lives, not exact spots: many records are georeferenced to a locality centroid (a nearby village or river mouth) rather than the precise catch site, some are historical or low-precision, and the occasional point may be a misidentification, an aquaculture record, or a feral occurrence well outside the native range — the Asian swamp eel, for one, is an established invader in the Florida Everglades. Many small, recently-described spiny eels have no public records yet — an empty map is honest, not an error. No coordinates are invented.

← Browse the Eels index