Red Squirrelfish (Sargocentron rubrum)

What is a Red Squirrelfish?

The Red Squirrelfish (Sargocentron rubrum) is a striking nocturnal marine fish known for its vibrant red coloration, large reflective eyes, and bold silver-white markings. Found throughout the Indo-Pacific and Red Sea, this species inhabits caves, ledges, and reef overhangs where it remains sheltered during the day before emerging at dusk to feed.

Red Squirrelfish are popular among marine aquarists seeking an unusual and eye-catching display fish. Their bright red colour remains visible under aquarium lighting, and their fascinating nocturnal behaviour adds a unique dimension to reef and fish-only aquariums. While generally peaceful towards similarly sized fish, they may prey upon small crustaceans and very small fish that can fit into their mouths.

Care Guide

Scientific Name

Sargocentron rubrum

Common Names

• Red Squirrelfish
• Redcoat Squirrelfish
• Soldierfish

Care Level

Easy to Moderate

Temperament

Peaceful to Semi-Aggressive

Reef Safe

With caution

Minimum Tank Size

250 Litres

Adult Size

Up to 30 cm

Diet

Carnivore

Origin

Indo-Pacific, Red Sea

Lifespan

5–10+ Years

Water Parameters

• Temperature: 24–27°C
• Salinity: 1.023–1.026 SG
• pH: 8.1–8.4
• Alkalinity: 8–12 dKH
• Nitrate: <20 ppm

Feeding

Red Squirrelfish are carnivorous predators that primarily feed on small crustaceans and zooplankton in the wild.

Recommended foods include:

• Mysis shrimp
• Brine shrimp
• Krill
• Chopped prawns
• Marine pellets
• Frozen carnivore preparations
• Copepods and zooplankton-based foods

Feed once or twice daily, preferably during the evening when they are naturally most active.

Tank Setup

Provide plenty of caves, ledges, and shaded areas where the fish can retreat during daylight hours. Live rock structures are ideal as they replicate the fish's natural habitat. Moderate water movement and stable water quality are important for long-term success.

Tank Mates

Suitable tank mates include:

• Clownfish
• Tangs
• Angelfish
• Wrasses
• Rabbitfish
• Larger gobies
• Hawkfish

Avoid keeping with very small shrimp, tiny gobies, or ornamental crustaceans that may be viewed as food.

Common Mistakes

Not Providing Enough Hiding Places

Red Squirrelfish spend much of the day hidden within caves and rockwork. Without adequate shelter they can become stressed and less active.

Keeping With Tiny Tank Mates

Although generally peaceful, they are opportunistic predators and may consume very small fish and crustaceans.

Underfeeding

These active nocturnal hunters require a varied carnivorous diet to maintain their health and colouration.

Using Excessively Bright Lighting Without Shelter

Strong reef lighting is not a problem if shaded areas are available. Lack of cover can cause stress and reduced activity.

Assuming They Are Fully Reef Safe

While they do not typically bother corals, they may prey on ornamental shrimp, tiny crabs, and other small invertebrates.

Frequently Asked Questions

Are Red Squirrelfish reef safe?

They are generally considered reef safe with corals but may eat small shrimp, crabs, and other ornamental crustaceans.

How big does a Red Squirrelfish get?

Adults can reach approximately 30 cm in length.

Why does my Red Squirrelfish hide all day?

This is completely normal behaviour. Red Squirrelfish are naturally nocturnal and become most active during dusk and nighttime hours.

Can Red Squirrelfish live with shrimp?

Small ornamental shrimp may be at risk. Larger cleaner shrimp may sometimes coexist, but caution is advised.

What do Red Squirrelfish eat?

They readily accept frozen foods, marine pellets, mysis shrimp, krill, and other meaty aquarium foods.

Are Red Squirrelfish aggressive?

They are generally peaceful toward similarly sized fish but can become territorial toward other squirrelfish in smaller aquariums.

Why Buy a Red Squirrelfish?

• Brilliant red coloration that stands out in marine aquariums
• Unique nocturnal behaviour
• Hardy and adaptable once established
• Reef safe with corals
• Fascinating large reflective eyes
• Excellent addition to fish-only and reef aquariums
• Relatively easy to care for compared to many specialty marine fish

The Red Squirrelfish is a fantastic choice for aquarists looking for something different from the usual reef fish. Its vivid colour, hardy nature, and intriguing nocturnal lifestyle make it a captivating addition to larger marine aquariums.