Aquarium Fish Identification: Tropical & Freshwater Species

Why Aquarium Fish Identification Matters

Correct identification isn't just about naming your fish — it's about providing proper care. Different species have vastly different requirements for tank size, water temperature, pH, diet, and compatibility. A fish labeled "assorted cichlid" at the pet store could be a peaceful ram or an aggressive jack dempsey — and putting the wrong one in your community tank can be disastrous.

The Fish Identifier app lets you snap a photo of any fish — at the store, at an auction, or in your tank — and instantly know the species, along with care requirements. No more guessing or mislabeled fish causing problems.

Freshwater Community Fish

Community fish are peaceful species that coexist well in a shared tank. They're the backbone of most home aquariums.

Tetras

Tetras are small, colorful schooling fish from South America. Neon tetras are iconic — a brilliant blue-red stripe on a tiny body. Cardinal tetras look similar but the red extends the full length of the body (only halfway on neons). Rummy-nose tetras have a distinctive bright red head. Black skirt tetras have flowing dark fins. All tetras do best in groups of 6+ in planted tanks.

Livebearers: Guppies, Mollies & Platies

Livebearers give birth to free-swimming fry (no eggs). Guppies are tiny and come in endless color varieties — males have large, colorful tails while females are larger and plainer. Mollies are larger, available in black, gold, silver, and dalmatian patterns. Platies are chunky, colorful, and incredibly hardy — perfect for beginners. Swordtails are close relatives with a distinctive elongated lower tail fin in males.

Corydoras & Plecos

Corydoras catfish are adorable bottom-dwelling scavengers with armored plates. Bronze and peppered corys are most common, but there are over 170 species. They should be kept in groups of 5+. Plecostomus (plecos) are armored catfish known for algae eating — but beware, common plecos can reach 2 feet! Bristlenose plecos stay smaller (4-5 inches) and are much better for home aquariums.

Bettas & Gouramis: The Labyrinth Fish

Labyrinth fish have a special organ that lets them breathe atmospheric air. Betta fish (Siamese fighting fish) are the most popular aquarium fish worldwide. Males have spectacular flowing fins in every color imaginable — halfmoon, crowntail, plakat, and double tail are popular fin types. Males are aggressive toward each other and should be kept alone or in community tanks with peaceful tankmates.

Gouramis range from tiny sparkling gouramis (1.5 inches) to giant gouramis (2+ feet). Dwarf gouramis are popular for community tanks — males are vibrant red and blue striped. Pearl gouramis have beautiful iridescent spots. Honey gouramis are peaceful golden-orange fish perfect for nano tanks.

Cichlids: The Personality Fish

Cichlids are known for their intelligence, personality, and often aggressive territorial behavior. They range from tiny shell-dwellers to massive oscar fish.

Marine Aquarium Fish

Saltwater aquariums host some of the most spectacular fish on earth. They require more equipment (protein skimmers, live rock, RO/DI water) but reward you with incredible biodiversity.

Clownfish (made famous by Finding Nemo) are the most popular marine aquarium fish. Ocellaris clownfish are orange with white bars edged in black. They host in anemones and are among the easiest marine fish to keep. Royal gramma are stunning purple-and-yellow basslets. Yellow tangs are bright yellow herbivores that need large tanks. Mandarin dragonets have psychedelic blue-green-orange patterns and are considered the most beautiful marine aquarium fish.

Angelfish (marine, not freshwater angelfish) include the emperor angelfish (blue-yellow horizontal stripes), French angelfish (dark body with yellow scale edges), and flame angelfish (bright red-orange with blue-black accents). Butterflyfish, wrasses, and chromis round out popular reef-safe choices.

Identifying Aquarium Fish with AI

At the pet store, at a fish show, or looking at an unlabeled tank online — the Fish Identifier app lets you snap a photo and instantly know the species. It covers tropical freshwater, cichlids, marine species, and rare ornamental fish. Perfect for: