How to Choose Healthy Neon Tetras, Panda Corydoras & 8 More Aquarium Fish

What to notice

Neon Tetras are small schooling fish with an iridescent blue stripe and red coloration on the rear half of the body. Shop lighting and recent transport can temporarily reduce color, so judge color alongside body shape, breathing, swimming control, and participation in the group.

A brief scatter when someone approaches can be normal. Persistent separation becomes more concerning when it is combined with weight loss, breathing effort, poor posture, fading that does not improve, or failure to respond to the school.

What to notice

The trade name remains Panda Corydoras, while FishBase lists Hoplisoma panda as the accepted name and retains Corydoras panda as the familiar former combination. The dark eye mask, dorsal marking, and tail-base marking should be clear, but pattern strength can vary with stress and lighting.

Corydoras alternate between resting and quick bursts of activity. A fast trip to the surface can be normal air-gulping behavior. Repeated distressed surfacing, heavy gill movement, poor balance, or similar behavior across the tank is a reason to stop and ask about water quality and recent handling.

What to notice

The Lambchop Rasbora is a small copper-to-orange schooling fish with a dark, narrow marking that widens toward the rear. Retail labels can be confused with Harlequin and Glowlight or Hengel's Rasboras, so identity belongs in the purchase check.

The group may tighten when startled and spread out once calm. Short chases can occur during display, but one fish should not be relentlessly driven away from food or shelter. Judge a quieter fish by breathing, condition, posture, and ability to rejoin the group rather than activity alone.

What to notice

Black Ghost Knifefish have a long dark body, a pale band near the tail, and an extended anal fin that produces smooth forward and backward movement. They are often reserved under bright shop lighting. Look for straight posture, steady breathing, and controlled movement when the fish emerges.

Hiding in a tube, cave, or dark corner during the day can be normal. Ask to observe the fish under calmer or dimmer conditions and ask whether staff have seen it feed. Frantic exposure, body damage from inadequate shelter, or inability to swim normally is different from choosing cover.

What to notice

An Oranda combines a deep fancy-goldfish body with a fleshy head growth called a wen. The wen is normal for the variety; injury, inflamed tissue, trapped debris, or tissue compromising the eyes or gill covers should not be dismissed as just an Oranda feature.

The rounded body and wen are intentional, and an Oranda will not swim like a Comet. That does not make chronic loss of balance normal. Watch long enough to see the fish turn, stop, rise, descend, and feed. A specialized body shape should still function.

What to notice

Blood Parrot Cichlids are domestic hybrids with a compact body and a characteristically restricted mouth. Individual form and color vary. Focus on function: can this fish breathe, swim, turn, feed, and compete without obvious distress? No single scientific binomial should be presented as though this trade form were a natural species.

Individuals may be shy, territorial, or pushy. Hiding after a disturbance is not automatically illness; persistent inability to feed, relentless attack, damaged fins, heavy breathing, or failure to recover is more concerning.

What to notice

Red Zebra Cichlids are Lake Malawi mbuna. Despite the common name, trade fish can be orange, red-orange, or blue depending on sex and color form. Color alone is a poor identity or health test; body condition, jaw alignment, fins, breathing, swimming, and the social setting provide better evidence.

Territorial display and chasing are normal parts of mbuna behavior, but the sales tank should still allow fish to escape, rest, and feed. Continuous attack, injury, collapse in a corner, or inability to reach food is not a harmless display.

What to notice

Featherfin Squeakers have three pairs of barbels and, in larger fish, a tall dorsal fin with extended rays. Juvenile pattern and proportions differ from adults. Shop specimens often rest under cover, so condition, breathing, barbel and fin integrity, and controlled movement matter more than constant daytime activity.

Sheltering during bright hours can be normal. A Featherfin may also use an unusual resting angle against decor, but it should be able to right itself and swim with control. Ask to observe it during feeding or under calmer lighting rather than assuming hiding equals sickness—or that total unresponsiveness is normal.

What to notice

Phoenix Rasboras are tiny red-toned schooling fish with dark side markings. At their size, loss of body condition can be easy to miss and a retailer label can be confused with other Boraras. View the fish from the side, compare several individuals, and confirm the identity before using species-specific compatibility data.

A shoal may compress, fade, or hide after transport or sudden movement. Give the group time to settle. One fish remaining apart and weak after the others recover deserves closer attention, especially when it is also thin or breathing fast.