Freshwater Fish

Paradise Fish

Macropodus opercularis

The hobby's first tropical fish, with a temper · Intermediate

Lifespan: 6-8 years, occasionally 10
Adult size: 3-4in / 8-10cm including tail streamers
Min. habitat: 20 gallon long (75L) minimum, planted, tight lid, heater optional
Social needs: One male alone, or one male with 2-3 females in 30gal+; never two males
Diet: Omnivore, insect-leaning (pellets, frozen bloodworm, brine shrimp)
Time: 10-15 min daily; weekly water change
Cost: Low

Overview

The paradise fish was the first tropical aquarium fish kept in the West, arriving in Paris in 1869 and captivating keepers decades before the betta.
Males wear alternating blue and red-orange vertical bars and trail a deeply forked tail into long streamers, so a good specimen still looks remarkable today.

What separates it from the dwarf, honey, and pearl gouramis elsewhere on this site is that it is subtropical, not tropical, and lives happily in an unheated indoor tank between about 61 and 79F (16-26C).
It pairs that toughness with the sharpest temper of any gourami here, behaving more like a territorial wild betta than like its placid cousins.

The hardiness is real, but so is the aggression, and the species suits a keeper willing to plan the whole tank around one fish.
It rates Intermediate not because it is hard to keep alive, but because it is hard to keep with anything else.

A single paradise fish needs a 20 gallon long (75L) at minimum, and the long, shallow footprint matters because this is a patrolling surface-oriented fish, not a tall-tank fish.
Furnish densely with plants, floating cover, and broken sight lines, keep flow gentle, and leave a calm surface, because like all gouramis it is a labyrinth breather that must sip air.
A tight-fitting lid is non-negotiable, both because it is an accomplished jumper and because it needs a layer of warm, humid air above the water.

Room temperature is genuinely fine, which makes this one of very few striking fish for heaterless setups, though it should not sit below about 55F (13C) for long and sustained temperatures above 80F (27C) run its metabolism hot.
Water chemistry is exceptionally forgiving, with soft to hard water and a pH anywhere from about 6.0 to 8.0 accepted.

Never house two males together, because they will fight until one is seriously injured or dead.
One male with two or three females can work in a heavily planted 30 gallon (110L) or larger, and females alone can be kept in small groups though they will still squabble, but the classic arrangement is a single male as the tank's only paradise fish.

Paradise fish are omnivores that lean strongly toward insects and other live prey.
Feed a quality insect-based pellet or flake as the staple, rotated with frozen or live bloodworm, brine shrimp, daphnia, and mosquito larvae to keep colour and condition up.

Anything that fits in its mouth is food, so cherry shrimp, fry, and the smallest nano fish are prey items, not tankmates.
It will also pick snails and small pest invertebrates off the glass, which some keepers count as a feature.

Feed once or twice daily, offering only what is finished within two minutes.
This is a greedy, gorging feeder that becomes obese on generous portions, so lean feeding with an occasional fast day serves it better.

This is one of the hardiest aquarium fish ever kept, and that reputation is the biggest threat to its welfare, because it is still used to excuse bowls, unfiltered tanks, and neglected water.
A paradise fish surviving bad conditions is not thriving in them, and proper filtration plus a weekly water change is what turns survival into a 6-8 year lifespan.

Most real injuries are social rather than infectious, with torn fins and scale damage from fights or harassment opening the door to fungus and bacterial infection.
Check fins weekly, and treat any ragged edges as a stocking problem to fix, not just a wound to medicate.

Beyond that, watch for ich after temperature swings in unheated rooms, and keep the surface air warm and humid under the lid to protect the labyrinth organ.
Quarantine new arrivals as standard.

Expect a bold, intelligent fish that watches the room, learns the feeding routine, and begs at the glass with real personality, much like a betta but with more presence.
Kept alone, it makes an outstanding single wet pet in the way a betta does.

Toward other fish it is the least forgiving gourami in the hobby.
Males flare and fight each other seriously, and slow, long-finned, or small tankmates such as bettas, fancy guppies, dwarf gouramis, and shrimp will be harassed, shredded, or eaten.

In larger tanks, fast, robust, similar-sized schoolers such as giant danios or larger barbs can hold their own, but every community attempt needs an exit plan.
Males build bubble nests and drive females hard during spawning, so a spawned female needs cover and usually removal afterward.