My red-tailed shark seems peaceful. Will it nip my neon tetras?

Red-tailed sharks often appear calm when young but develop aggressive territorial behavior as they mature. Most attacks occur between 3-5 inches.

Will a 55-gallon tank prevent red-tailed sharks from nipping neon tetras?

Larger tanks give tetras more room to escape but do not eliminate the nip-and-chase behavior. Sharks patrol the mid-levels where tetras swim.

Can I keep two red-tailed sharks with neon tetras?

Red-tailed sharks are highly territorial toward their own kind. Multiple sharks will fight, stressing the entire tank including the tetras.

Can Neon Tetra Live With Red-Tailed Shark?

By Alex WalshLast reviewed Apr 18, 2026

No, red-tailed sharks are aggressive fish that nip fins and stress neon tetras even in large community tanks.

Why

Red-tailed sharks grow to 4-6 inches and are aggressive territorial fish that claim large portions of the tank.
Neon tetras stay at 1.5 inches. Sharks of 4-6 inches are fast enough to catch and nip slow-moving tetras.
Red-tailed sharks are notorious fin-nippers, especially toward fish that share their swimming level.
Tetras nipped repeatedly develop ragged fins, infections, and chronic stress that lowers their lifespan.
Water parameters overlap (72-79F, pH 6.5-7.0), which makes the pairing look viable on paper.

Minimum shared tank

55 gallons

Shared temperature range

72-79°F

What could go wrong

Red-tailed sharks chase and nip neon tetras repeatedly, causing stress, injuries, and eventual death even without outright eating them.

If you keep them in separate tanks

Sized for the 55 gallon minimum this pairing needs. Affiliate links — we earn a small commission if you buy through them.

Fluval 307 Performance Canister Filter

Oversized filtration is what lets you stock two species together without water quality crashing. Rated for a tank slightly larger than the 55 gallon minimum.

Check Price on Amazon See full guide

Eheim Jager 300W Thermostat Heater

Holds a steady temperature inside the 72-79°F window both species need.

Check Price on Amazon

API Freshwater Master Test Kit

Keep ammonia, nitrite, and nitrate in check. Two-species tanks have more bioload and less margin for error than single-species setups.

Check Price on Amazon See full guide

Better pairings to consider

Red-tailed sharks do well with larger barbs or gouramis that can hold their own. Neon tetras do well with peaceful community fish like rasboras or corydoras.