Peacock Mantis Shrimp as a Pet: Tank Size & Lifespan

Peacock mantis shrimp are aggressive, smart, and can even break glass. They are not community tank pets. But if you’re willing to set up a solo saltwater tank, they are fascinating, easy to care for, and highly interactive.

The minimum tank size is 10 gallons for small species, 20+ for large. Use acrylic — not glass — for smashers. They can chip or shatter glass panels. Feed them frozen mussels, clams, or shrimp. They don’t need live food. Most species live 2–5 years in captivity.

This guide covers tank setup, feeding, lifespan, and the exact species that work best for home aquariums.

Quick Notes about Mantis Shrimp

Origins and Natural Habitat 

Mantis shrimp are usually found in shallow subtropical or tropical waters, with some types or species occasionally found in sub-Antarctic waters. They are found along shores, usually living in abandoned burrows to maneuver in, and bent capture prey when spotted. 

Interesting fact: About 340 million years ago (before the first dinosaurs appeared on the scene), they branched from other members of the class Malacostraca (shrimp, crabs, crayfish, and lobsters).

Description of the Mantis Shrimp

Mantis shrimp are not true shrimp. They are stomatopods. They get their name because they resemble a praying mantis (forelimbs) and a shrimp (body shape) at the same time. Their biology is so bizarre that scientists have assigned them the nickname “shrimp from Mars“.

Basic anatomy:

• Carapace — a hard shell that covers the head and thorax.
• Abdomen — segmented, curled under the body, with swimmerets for swimming.
• Telson — the tail fan at the rear, used for rapid backward escape movements.
• 5 pairs of walking legs — used for crawling and gripping surfaces.
• 1 pair of raptorial appendages — the folded claws used for hunting (the defining feature).

Size ranges from 1 to 15 inches (2.5 – 40 cm) depending on species. The largest species, *Lysiosquillina maculata*, can reach 40 cm (15 inches).

Eyes: Their eyes are among the most complex in the animal kingdom:

• 12–16 color photoreceptors — 4x more than humans.
• Trinocular vision — each eye can gauge depth on its own.
• Circularly polarised light detection — not documented in any other animal.

Despite having more color receptors, research suggests they are worse at differentiating color than humans. Scientists believe their eyes function more like a satellite, feeding raw data directly to their brain for instant reaction.

Molting: Like all crustaceans, mantis shrimp molt to grow. Their new exoskeleton is soft, and they are highly vulnerable. They will hide in their burrow and refuse food for several days before and after molting. Never attempt to handle them or feed them during this time.

Mantis Shrimp Types – “Smashers” and “Spearers”

All Mantis shrimp species are often divided into ‘Spearers’ or ‘Smashers’, depending on the kinds of claws they need and tactics they use to kill the prey.

by Roy Caldwell

Spearers

Spearers have spiny appendages (elongated, open dactyls) with barbed tips. They use them to stab soft-bodied prey, like differing types of worms and fish. The range of distances from which the Mantis shrimp usually initiate their strikes is about 1 – 3 cm.

Smashers

Smashers have more developed club-like appendages (highly calcified, massive dactyls) that can bludgeon and smash their hard-shelled prey (like crabs, lobsters, shrimp, snails, etc.) to pieces.

Interesting fact:  Beneath their hard-coated clubs, Mantis shrimp have special layers of elastic polysaccharide chitin, which acts as a shock absorber. Researchers have even studied their cell structure for advanced body armor for combat troops, car frames, and aircraft panels.

Lifespan of Mantis Shrimp

There are records that large Mantis shrimp lived for over 20 years. However, in aquariums, hobbyists usually keep small species (3 – 5 inches or 7 – 12 cm) that usually do not live more than 3 – 6 years.

Typical Behavior of the Mantis Shrimp

Mantis shrimp are ruthless, smart hunting machines. Their behavior depends on the species:

• Spearers — pure ambush predators. They hide in sandy burrows and execute surprise attacks on evasive prey (fish, shrimp).
• Smashers — more persistent hunters. They search for prey away from their burrows and will pursue it until caught.

Key behavioral traits:

• Solitary — they spend most of their lives in burrows or cavities. Some species mate for life, but most are solitary.
• Intelligent — they can learn to recognize you as the “Bringer of Food” and will come out of hiding for feeding.
• Extremely fast — acceleration up to 30 body lengths per second. Scaled to human size, that’s 130 mph (210 km/h).

Interesting fact: According to a study, small species (like Alachosquilla vicina – 2.5 cm) attack several times faster than large species (like Lysiosquillina maculata – 13–17 cm).

Feeding Mantis Shrimp

Mantis shrimp are quick, deadly predators that will eat any aquatic creature they can catch. Their diet depends on the type:

• Spearers — prefer evasive prey like fish and shrimp.
• Smashers — target hard-shelled, sedentary prey like crabs, lobsters, snails, clams, and mussels. They smash the shell to access the soft tissue.

What to Feed

Frozen foods are the easiest and safest option. Most mantis shrimp readily accept:

• Mussels, prawns, scallops, clams
• Squid, crab meat
• Various fish (silversides, smelt)
• Live snails or small crabs (treats, not staple)

Human seafood markets and bait stores are excellent sources of varied, affordable food. Offering different species (shrimp, fish, snail, abalone) improves overall health.

Important: Cut food into pieces no larger than the mantis shrimp’s head. They will reject oversized items.

How Often to Feed

• Adults: Feed every 2–3 days.
• Juveniles: Feed daily — they need protein for growth.
• Portion size: Offer a piece roughly the size of their body (not including claws). They will eat until full and then stop.

Overfeeding pollutes the water. Remove uneaten food after 4–6 hours.

Feeding Tips & Troubleshooting

They can be picky. Mantis shrimp sometimes kill live food out of territorial aggression without eating it. They may also grab unfamiliar food, retreat to their den, and then toss it out — this is normal. Over time, most will accept new foods.

Transitioning from live to frozen: If your mantis shrimp only eats live food, start by offering freshly killed prey (still moving slightly). Then gradually introduce defrosted frozen food. This usually works within 1–2 weeks.

Tong-feeding: Using tongs allows you to offer a varied diet and observe their behavior up close. It also prevents food from rotting in the tank if they refuse it.

Signs of hunger: They become more active and visible at the burrow entrance. A mantis shrimp that ignores food for more than a week may be stressed, preparing to molt, or sick — check water parameters immediately.

Keeping and Housing Mantis Shrimp

Mantis shrimp are hardy and easy to care for — they tolerate a range of water conditions and don’t need special equipment. But they do have specific requirements for housing.

Aquarium Type

Do not use a glass tank for smashers. Even small individuals can chip the glass. Large species can shatter it. There are multiple reports of mantis shrimp attacking their own reflection through the glass.

Use acrylic instead. Acrylic tanks are more expensive but will withstand impacts. If you’re keeping any smasher species over 8 cm (3 inches), acrylic is mandatory.

Pro tip: Mantis shrimp can jump. Use a tight-fitting lid with no gaps.

Tank Size

• Small species (1–3 inches / 2.5–7 cm): 10 gallons (40 liters) minimum.
• Large species (over 8 inches / 20 cm): 20 gallons (80 liters) minimum.

Larger tanks are always better — they provide more stable water chemistry and more room for the mantis shrimp to establish territory. But a bigger tank also means more live rock, more sand, and higher setup costs.

Critical: The tank must be fully cycled before introducing a mantis shrimp. They are hardy, but ammonia and nitrite spikes will kill them.

Water Parameters

• Temperature: 22–26°C (72–80°F)
• Salinity: SG 1.018–1.025
• pH: 8.0–8.5
• KH: 8–16
• Nitrate: Below 20 ppm

Mantis shrimp are more tolerant of parameter swings than most marine invertebrates, but stability is still important. Test weekly and top off evaporated water with fresh RO/DI water — not saltwater.

Substrate and Decorations

Mantis shrimp are ambush predators. They need places to hide. The setup depends on the type:

• Spearers: Deep sand is mandatory. Sand bed should be at least 1.5× the length of the animal. They burrow and ambush prey from the burrow entrance.
• Smashers: Prefer tube-shaped cavities. Provide live rock, gravel, and PVC pipes of varying diameters. They often close off the cavity entrance at night.

Expect rearranging. Mantis shrimp are strong and will push, drag, dig, and move everything in the tank. They can shift large amounts of sand and gravel to build stable burrows. Aquascaping is temporary — they will redecorate to their liking.

Filtration and Water Flow

Filtration requirements are modest:

• Protein skimmer — recommended but not mandatory. Helps with water quality, especially with meaty foods.
• Canister or HOB filter — enough for the tank size. Mantis shrimp produce waste from their carnivorous diet.
• Moderate water flow — not too strong. They don’t come from high-flow environments. Aim for 5–10× tank volume per hour.
• Aquarium light timer — set to mimic a natural day/night cycle (10–12 hours of light).

Airborne chemicals are a real risk. Fumes from cleaning products, paints, floor waxes, and air fresheners can be toxic to mantis shrimp. Place the tank in a well-ventilated area away from sources of chemical fumes.

Acclimation

Regardless of their hardiness, always drip acclimate them to your tank water. Mantis shrimp are shipped in water that may have different pH, salinity, and temperature. Slow acclimation over 1–2 hours reduces stress and prevents shock.

Choosing the Right Species For Your Tank

There are over 400 species of mantis shrimp. The most common aquarium species are listed below. For a complete list, see Berkeley University of California’s list.

Mating and Communicating

Mantis shrimp have evolved complex communication to avoid fatal fights with their own species. Killing a rival is not a good survival strategy for the population.

They communicate using:

• Body posture — raised or lowered posture signals dominance or submission.
• Chemical and visual cues — color and scent convey information about sex and readiness to fight.
• Posturing and ritualized displays — they display their claws and telson (tail fan) before actual combat.

Most mantis shrimp are territorial and defend their burrows. When two individuals spar, they non-lethally tap each other on the hard shells of their backs or tails. This lets them assess who is the stronger contestant without causing fatal injuries. If neither retreats, they may target the opponent’s telson — which is also non-lethal.

Research has documented that these ritualized contests are surprisingly complex and can involve multiple stages of escalation.

Breeding Mantis Shrimp

After mating, the female carries fertilized eggs beneath her body for 5–6 weeks. Once hatched, they enter a planktonic larval stage, drifting in the water column for weeks before settling to the bottom and molting into their first benthic stage.

It takes approximately 50–70 days for them to reach maturity and start reproducing.

Note: Breeding mantis shrimp in captivity is challenging. The larvae require specialized feeding and water conditions, and most attempts fail without a dedicated setup. If you’re a beginner, focus on keeping one alive before attempting to breed them.

Mantis Shrimp and Suitable Tankmates

There are no suitable tankmates for a mantis shrimp.

They will eat absolutely anything they can catch (Spearers) or destroy (Smashers). Small fish, crabs, shrimp, snails — all are prey.

They are intelligent and will not attack anything too big for them… yet. But the moment a fish or invertebrate is small enough, it’s food.

Mantis shrimp are fascinating, but they are strictly species-only pets. If you want a community tank, choose something else.  

Mantis Shrimp — Uninvited Guest in the Tank

Mantis shrimp are often introduced to aquariums accidentally through live rock or coral. These hitchhikers are resilient and can survive unnoticed for weeks or months.

In most cases, the first sign of their presence is a declining fish or invertebrate population with no obvious cause. If you notice shrimp, snails, or small fish disappearing, inspect your rockwork at night with a flashlight.

Note: Small mantis shrimp are excellent at hiding. You may hear clicking or tapping sounds from the tank at night — this is often a mantis shrimp breaking shells.

How to Remove Mantis Shrimp from the Tank

There are two reliable methods to remove a mantis shrimp.

1. DIY Bottle Trap

A simple bottle trap works effectively. Here’s how to make it:

1. Cut the top off a plastic bottle at the widest point.
2. Invert the top piece and place it upside down into the bottom half.
3. Punch a few holes on opposite sides of the bottom half.
4. Secure with a rubber band across both ends.
5. Bait with krill, shrimp, or other meaty food.
6. Place the trap near the mantis shrimp’s burrow at night.

Expect this to take several nights. Mantis shrimp are cautious and may ignore the trap for a few days or even weeks. Be patient.

2. Freshwater Dip

This method works only if you know exactly where the mantis shrimp is hiding.

• In the tank: Squirt freshwater directly into the burrow. The mantis shrimp will often come out — catch it with a net.
• On a rock: Remove the entire rock and place it in a container of freshwater. The mantis shrimp will swim out within a few minutes.

Warning: Freshwater dips are stressful and can be fatal to the mantis shrimp. Use this method only if you are removing it permanently.

Handling a Mantis Shrimp

Mantis shrimp strike out with their raptorial appendages when threatened. They can cause severe injuries requiring stitches — divers and shrimpers call them “Thumb splitters.”

Never use your fingers near a mantis shrimp. They will attack anything that enters their territory, including fingers.

Always use:

• Forceps or tongs — for feeding and moving objects in the tank.
• A net — for catching or transferring the mantis shrimp.

If you need to move a mantis shrimp, use a net and avoid cornering it. They are fast and will strike if they feel threatened.

Interesting Facts About Mantis Shrimp

Punch Speed and Force

Mantis shrimp throw the fastest punch of any animal. Smashers can strike at speeds of 14–23 m/s — the same velocity as a .22 caliber bullet. Their fists accelerate from their body at over 50 mph, delivering a force of over 1,500 newtons. That’s enough to smash through crabs and clamshells.

Their punch is so fast it creates cavitation bubbles — tiny implosions that generate a flash of light and a shockwave. This acts as a double punch: even if the mantis shrimp misses, the shockwave can stun or kill the prey.

Shock-Absorbing Clubs

Beneath their hard-coated clubs, mantis shrimp have layers of elastic polysaccharide chitin that act as a shock absorber. Researchers have studied their cell structure for applications in body armor, car frames, and aircraft panels.

Acceleration

Mantis shrimp can reach 30 body lengths per second. To scale, that’s like a person running 130 miles (or 210 km) per hour.

Their punch is so fast it leads to ‘cavitation’ bubbles. When these bubbles collapse, they generate a flash of light (sonoluminescence) and temperatures hot enough to boil the water in that tiny area for a fraction of a second. This causes an intense shockwave which is sort of a double punch and may stun, dismember or kill prey instantly – if the mantis shrimp misses the target.

Should You Keep a Mantis Shrimp? Pros & Cons

If you’re willing to set up a solo saltwater tank with acrylic glass and feed them frozen seafood, a mantis shrimp makes a unique, intelligent, and low-maintenance pet. If you want a community tank with fish and snails — skip it.

Important: Check local laws. In some regions (like parts of Australia and California), mantis shrimp are restricted or illegal to keep as pets due to their destructive potential if released into the wild.

Frequently Asked Questions

Are mantis shrimp freshwater or saltwater?

Strictly saltwater (marine). They cannot survive in freshwater tanks.

How long do mantis shrimp live?

Small species: 2–5 years in captivity. Large species: up to 20 years in the wild, but rarely reach that age in home aquariums.

What size tank does a mantis shrimp need?

Small species (under 3 inches): 10 gallons minimum. Large species (over 8 inches): 20 gallons minimum. Use acrylic for large smashers — they can chip or break glass.

Can a mantis shrimp break aquarium glass?

Yes. Large smasher species can chip or shatter glass panels. Acrylic tanks are strongly recommended for any smasher over 8 cm (3 inches).

Can I keep a mantis shrimp with other fish or invertebrates?

No. Mantis shrimp are solitary predators that will eat any tankmate they can catch or kill. They are strictly species-only pets.

How do I know if I have a mantis shrimp in my tank?

The most common sign is fish or invertebrates disappearing without a trace. You may also hear clicking or tapping sounds from the tank at night.

What do mantis shrimp eat?

Carnivores. Smashers eat hard-shelled prey (crabs, snails). Spearers eat soft-bodied prey (fish, worms). In captivity: frozen mussels, clams, shrimp.

What’s the difference between a smasher and a spearer?

Smashers have club-like claws for bludgeoning hard-shelled prey. Spearers have spiny, barbed claws for stabbing soft-bodied prey like fish and worms.

Can I keep two mantis shrimp together?

Generally, no. They are solitary and will fight to the death. The only exception is if you introduce a mated pair of small species (like Alachosquilla vicina) at the exact same time into a large enough tank. But for 99% of hobbyists: one tank, one mantis shrimp.

Who would win in a fight — a mantis shrimp or a pistol shrimp?

At equal size, the mantis shrimp would likely win.

• Mantis shrimp are built for combat — their clubs or spears deliver direct, focused strikes that can shatter shells. Their exoskeleton is heavily armored and can absorb impacts.
• Pistol shrimp rely on a cavitation bubble to stun prey from a distance. This works well on soft-bodied fish but is much less effective against a heavily armored stomatopod.

The pistol shrimp’s claw is also fragile — if damaged, it can no longer snap. The mantis shrimp’s primary weapon is far more durable. In a direct confrontation, the mantis shrimp’s speed, armor, and brute force give it a clear advantage.