Spined loach
Small European freshwater fish with a defensive eye spine
The spined loach is a small bottom-dwelling fish native to temperate Europe. It buries in sand by day and feeds at night, using intestinal breathing to survive low oxygen. Anglers and aquarists value its unique behaviour and distinctive appearance.
- Females grow larger than males, reaching 12 cm
- Breathes air through its intestine in low oxygen
- Buries in sand during the day to hide
- Has a sharp spine under each eye for defence
- Found in five specific river systems in England
What it is
This slender fish belongs to the true loach family. Adults usually measure eight to ten centimetres, though females can reach twelve. Their backs display yellow-brown hues with small grey scales along the spine, while bellies appear pale yellow or orange. Six barbels surround the mouth for sensing food. A sharp two-pointed spine sits beneath each eye, capable of delivering a painful sting if the fish is handled roughly.
Where it lives
Its distribution spans temperate Europe from the Volga River basin west to France. It avoids Ireland, Scotland, Wales and northern Scandinavia. In Britain, it inhabits five east-flowing river systems including the Trent and Great Ouse. Populations south of the Alps were once grouped here but are now considered distinct species. Close relatives replace it in Greece, Romania and Turkey.
How it lives
It prefers clear water with high oxygen levels in slow brooks or still ponds. During daylight hours, it buries itself in sandy or stony beds, exposing only its head and tail. Night brings activity as it consumes sand to extract small animals and organic matter. Nutrient-stripped sand exits through the gills. When oxygen drops, it swallows air at the surface to breathe via its intestine, expelling waste gas through the anus.
Breeding and life cycle
Spawning occurs between April and June. Females lay three hundred to one thousand five hundred eggs near the bottom on stones, roots or plants. Males fertilise them externally. Larvae emerge after four to six days. In the wild, these fish live three to five years, but captive specimens may survive up to a decade.
Fish and people
Aquarium keepers appreciate this species for its unusual habits and compact size. Its ability to breathe air allows it to survive in tanks with poor filtration, though clean water remains ideal. The defensive eye spine requires careful handling during maintenance. It is not typically raised for food due to its small size and bony structure.
Questions people ask about Spined loach
Can the spined loach hurt humans?
Yes, it has a two-pointed spine under each eye. If handled carelessly, this spike can inflict a painful sting. It is a defensive mechanism rather than an aggressive attack.
How does it breathe out of water?
It uses intestinal breathing as a backup. The fish swallows air at the surface, extracting oxygen through the intestinal wall. The used air is then expelled through the anus.
What do spined loaches eat?
They are bottom feeders that consume sand at night. They filter out small animals and organic material from the sediment, ejecting the clean sand through their gills.
Good reading and sources
The facts on this page come from the Wikipedia article "Spined loach", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.
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