Ocellated Featherback

• It breathes air: it comes to the surface and fills its modified swim bladder, which lets it survive in stagnant, oxygen-poor water.
• Its anal fin, joined to the tail fin, works as a single undulating band that gives it control of its movement to within millimetres.
• Aquarium escapes have established it in the canals of southern Florida, where it is an invasive species.
• It swims with a single, extremely long anal fin that runs the whole length of its belly and undulates like a curtain. That lets it move forwards and backwards with precision without moving its body, useful among roots and dense vegetation.
• It breathes air with its modified, vascularised swim bladder, which allows it to survive in waters very poor in oxygen.
• Its arched back and small head give it a knife-like profile, which is where the name comes from.
• The male guards the eggs, laid on submerged wood, and fans them until they hatch.
• It has established itself as an invader in Florida and in several countries outside its range, stemming from the aquarium trade.

Skeleton type

Vertebrate - internal bony skeleton (fish)

Habitat & environment

Slow rivers, lagoons and canals of South-East Asia

Sources consulted: https://en.wikipedia.org/wiki/Clown_featherback