The Americas
From the Amazon's blackwater basins to Caribbean reefs — the Americas hold the most popular freshwater biotopes and a wealth of Atlantic and Pacific saltwater life.
765 species · freshwater
Sub-regions
Northern Snakehead
FishChanna argus
A true apex predator that can survive days out of water. And is banned in many countries.
Oaxaca Cichlid
FishVieja zonata
A rare Mexican cichlid with big personality and even bigger space requirements.
Ocellate Freshwater Stingray
FishPotamotrygon motoro
A disc-shaped apex predator that can learn to recognize its keeper.
Ogre Catfish
FishAsterophysus batrachus
A gulper catfish that can swallow prey nearly twice its own size.
Olga
FishCorydoras simulatus
A rarely documented Colombian cory with a color pattern that keeps even experts guessing.
One-lined Pencilfish
FishNannostomus unifasciatus
A tiny pencilfish that swims at a permanent angle, day and night.
One-spot Eartheater
FishSatanoperca lilith
A rarely traded eartheater with a single bold flank spot and surprising social depth.
Orange dwarf toothcarp
FishNeoheterandria elegans
A tiny Colombian livebearer with a fascinating near-mammalian reproductive twist.
Orangefin Tetra
FishBryconops affinis
A restless, fast-moving shoaler from the Guiana Shield's coastal streams.
Orangeflossen
FishLaetacara fulvipinnis
A tiny blackwater cichlid with warm-toned fins and a gentle personality.
Orange Head
FishGeophagus sp. "Orange Head"
A vividly capped cichlid that rewards patient keepers with fascinating mouthbrooding family life.
Orinoco
FishAndinoacara sp. "Orinoco"
A mellow Orinoco cichlid that pairs easily and rewards patient breeders.
Orinoco Eartheater
FishBiotodoma wavrini
A slender eartheater that thrives in groups and rewards patient, experienced keepers.
Orinoco sailfin catfish
FishPterygoplichthys multiradiatus
A dinosaur-sized algae grazer built for decades of service in large tanks.
Orinoco Tetra
FishHemigrammus barrigonae
A rare Orinoco tetra that rewards patient keepers willing to seek it out.
Ornate Corydoras
FishCorydoras ornatus
A long-lived Tapajós bottom-dweller that thrives in sociable, peaceful groups.
Oscar
FishAstronotus ocellatus
The cichlid that recognizes your face and rearranges its own tank.
Otocinclus
FishOtocinclus vittatus
Tiny algae-grazing catfish that plasters itself to glass and plants alike.
Otocinclus affinis
FishMacrotocinclus affinis
Tiny Brazilian algae-eater with a habit of resting right on the front glass.
Otocinclus Catfish (Tank-Bred)
FishOtocinclus macrospilus
The most commonly sold oto, fragile at first but rewarding once settled.
Otocinclus cocama
FishA tiny Peruvian algae grazer with bold, zebra-like blotches and a gentle disposition.
Oyapock Cory
FishCorydoras condiscipulus
A long-lived Oyapock armored catfish that breathes air and blinks its eyes.
Oyapock Eartheater
FishGeophagus camopiensis
A rarely seen eartheater with elaborate mouthbrooding behavior and real personality.
Pacific Fat Sleeper
FishDormitator latifrons
A chunky estuarine predator that breathes air and swallows anything it can fit in its mouth.
Pacific Molly
FishPoecilia butleri
A personable little livebearer that grazes algae and practically eats from your hand.
Pacu
FishPiaractus mesopotamicus
A seed-crunching giant from South American floodplains that outgrows almost any home aquarium.
Painted Sailfin Catfish
FishLeiarius pictus
A majestic sailfin catfish only suited to those with truly enormous tanks.
Palespotted Corydoras
FishCorydoras gossei
A long-lived, peaceful bottom dweller that breathes air and blinks its eyes.
Panamanian Eartheater
FishGeophagus crassilabris
A rare Panamanian cichlid with a reddish glow and fascinating sand-sifting habits.
Panda Cory
FishCorydoras panda
The panda-patterned cory that's as personable as it is peaceful.
Panda Dwarf Cichlid
FishApistogramma nijsseni
A panda-patterned dwarf cichlid with fierce maternal instincts and blackwater roots.
Panda Uaru
FishUaru fernandezyepezi
A rare Orinoco cichlid that few hobbyists ever get to keep.
Pantanal Eartheater
FishSatanoperca pappaterra
A sand-sifting cichlid that fearlessly charges piranhas in the wild.
Pantano Cichlid
FishHerichthys pearsei
A surprisingly gentle giant from Mexican and Guatemalan river systems.
Parnaíba Eartheater
FishGeophagus parnaibae
A sand-sifting cichlid from Brazil that's gentler than its reputation suggests.
Parrot Cichlid
FishHoplarchus psittacus
A rare blackwater cichlid that defies its aggressive reputation in the right company.