Tropical Fish Encyclopedia: Popular Species Features & Tank Compatibility Guide

The world of tropical fish encompasses thousands of species, but here we spotlight the most popular staples. Learn each species' characteristics and compatibility to build your ideal aquarium.

Small Characins: Beautiful Schooling Classics

Neon Tetra - **Size:** Approximately 3 cm - **Temperature:** 24-28 degrees C - **Temperament:** Peaceful - The iconic blue and red lined body color defines tropical fish - Schools of 10 or more create especially stunning visual impact - Hardy and easy to keep; ideal as a beginner's first fish

Cardinal Tetra - **Size:** Approximately 4 cm - **Temperature:** 24-28 degrees C - **Temperament:** Peaceful - Similar to neon tetras but with red extending across the entire belly, creating more vibrant coloration - Slightly larger than neons, with more presence when schooling - Prefers soft, slightly acidic water but adapts to a wide range of conditions

Guppies: Endlessly Fascinating Selective Breeding

• Size: Males 3-4 cm, Females 4-6 cm
• Temperature: 23-28 degrees C
• Temperament: Peaceful, though males may flare fins at each other
• Enormous variety of tail shapes and color patterns
• Livebearers (eggs develop internally) making breeding easy
• Watch for overpopulation. Separate males and females, or include tankmates that eat fry for natural population control

Compatibility note: Avoid housing long-finned varieties with fin-nippers (like tiger barbs).

Corydoras: Bottom-Dwelling Cleanup Crew

• Size: 4-7 cm (varies by species)
• Temperature: 22-26 degrees C
• Temperament: Very peaceful
• Adorable bottom-dwellers that shuffle through substrate
• Popular species include Sterbai, Panda, and Aeneus
• Groups of 3 or more behave more confidently

Substrate selection: Use smooth, rounded sand like Tahitian Moon Sand or fine river sand to protect corydoras barbels. Soil works too, but avoid sharp-edged gravel.

Angelfish: Tank Centerpieces

• Size: Up to about 15 cm including height
• Temperature: 25-30 degrees C
• Temperament: Somewhat aggressive (especially as adults)
• The elegant triangular silhouette swimming gracefully earns the title "Queen of Tropical Fish"
• Adults may prey on small fish, so caution is needed with neon tetra tankmates
• Territorial behavior increases when pairs form

Betta: Solo Beauty

• Size: 5-7 cm
• Temperature: 25-28 degrees C
• Temperament: Males are extremely combative toward each other
• Abundant varieties including Halfmoon and Crowntail with dramatically spread fins
• Can be kept in small tanks or jars, though 5 liters or more is recommended
• Labyrinth organ allows breathing atmospheric oxygen, enabling filterless and airless keeping

Compatibility note: Never house males together. Mixed-sex and multi-species setups require caution; avoid fin-nippers.

Quick Compatibility Reference

| Combination | Rating | Notes | |-------------|--------|-------| | Neon Tetra x Corydoras | Excellent | Different water levels---ideal pairing | | Guppy x Neon Tetra | Good | Similar water quality preferences | | Angelfish x Neon Tetra | Caution | Adult angelfish may prey on neons | | Betta x Guppy | Poor | Bettas attack long-finned fish | | Corydoras x Angelfish | Good | Different water levels, minimal conflict |

Find Tropical Fish on BuriChoku

BuriChoku lets you purchase carefully raised tropical fish directly from breeders. Getting firsthand information about housing conditions and compatibility track records means fewer mistakes in fish selection. Find your perfect fish today.