Sparkling Gourami (Trichopsis pumila)

Sparkling Gouramis are a labyrinth fish, meaning they've got an accessory breathing organ that lets them gulp air directly from the surface, and they use it constantly enough that you'll notice the trips even in a well-oxygenated tank. They're also one of the few aquarium fish that produce an audible sound — a soft croaking or clicking noise made during territorial displays and courtship, faint enough you'll need a quiet room to catch it, but it's genuinely there. Small, peaceful, and content in a quiet corner of a planted tank, they're a good pick for a calm community setup that doesn't need another fast-swimming schooling fish competing for attention.