Acanthicus hystrix is the type species of its genus, the fish the entire Acanthicus group gets measured against, and it shares the same uncomfortable trade reality as its only relative: juveniles sell steadily, adults are almost never seen in private tanks. In practice, that gap between what’s bought and what actually gets kept says everything…

Acanthicus adonis gets sold as an adorable, spotted 10 cm juvenile, and that sale rarely comes with a warning about what happens next. In practice, this is one of the more honest test cases in the aquarium trade for the gap between “cute at the store” and “realistic to keep.” This guide covers what the…

Abramites hypselonotus rests at a steep head-down angle in the water, a posture so distinctive it gave the entire headstander group its name. In practice, this South American characin brings genuine personality to a planted tank, provided the tank is large enough and the plants tough enough to survive it. This guide covers the tank…

Abramis brama grows to 80 cm and 9 kilograms in the wild, which rules it out as an aquarium fish before diet or water chemistry even come up. In practice, this is a European pond, lake, and river species, the kind anglers target rather than something anyone keeps in a home tank. This guide covers…

Aborichthys garoensis carries an IUCN Vulnerable rating, a status its close cousin Aborichthys elongatus doesn’t share, and that single fact should shape how anyone approaches keeping it. In practice, this small loach from a single patch of hills in northeastern India comes with real conservation stakes attached, not just a care sheet. This guide covers…

Aborichthys elongatus needs water moving hard enough to challenge a powerhead, and that single requirement rules it out for most standard community tanks before diet or tankmates even enter the conversation. In practice, this loach comes from a genuinely narrow slice of the hobby: fast Himalayan foothill streams, cool water, and a body built to…