Cat Shark Care Guide: Coral Catshark Tank Size

Sharks are probably the last animal most people expect to see in a home aquarium, but some small species do well in large, well-run marine tanks.

“Cat shark” is a catch-all name for several groups of small, bottom-dwelling sharks, including catsharks, bamboo sharks and a few larger relatives. All of them need a big saltwater system, and the common mistake is buying a juvenile and discovering later that the tank is far too small.

The most popular choice, the coral catshark, grows to about 24-28 inches and needs a tank of at least 180 gallons. A tank of 200-300 gallons with a footprint of 6-7 feet long is a better target. Bamboo sharks need much more.

Cat Sharks Facts & Overview

“Cat shark” is a name used for several families (Hemiscylliidae, Scyliorhinidae, Pseudotriakidae) of saltwater sharks that are popular with home aquarists.

• Banded cat sharks, better known as bamboo sharks, are in the Hemiscylliidae family. Marbled and coral catsharks are in Scyliorhinidae.
• Scyliorhinidae species live in oceans around the world, and some are endemic, meaning they are only found in one area.
• Bamboo sharks from the family Hemiscylliidae live in Indo-Pacific Asia, from India to northern Australia and southern Japan.

False cat sharks belong to the family Pseudotriakidae. They are not kept as pets because of their size.

How long do cat sharks live?

With stable water and a good diet, coral catsharks are reported to live 15-20 years in captivity, and brownbanded bamboo sharks 20-25 years. That is a long commitment for a tank that costs thousands of dollars.

Where can you buy a cat shark, and what do they cost?

Specialty online marine stores sell them. Local shops rarely stock them because of their size. Prices change often. In recent years, marbled catsharks have been listed around $80-$85 for a half-grown juvenile, banded (bamboo) sharks about $150-$170 and coral catsharks about $300, so check current prices before you plan a budget. You can also buy an egg for around $45-$50. Raising a shark from an egg lets you watch it grow and may help it adapt to the tank, though hatching is not guaranteed.

What do cat sharks look like?

Color and size vary a lot between species. Most are dark or patterned, with a long, cylindrical body and a short, narrow head with cat-like eyes. Adult size ranges from roughly 24 inches to more than 40 inches, depending on the species.

Banded Cat Shark (Brownbanded Bamboo Shark)

Also called the bamboo shark (Chiloscyllium punctatum), this Hemiscylliidae member is recognized by dark bands on a pale body. Juveniles are boldly striped, and the bands fade as they age. FishBase lists a maximum of 132 cm (about 52 inches), though most reach 3-3.5 feet in captivity.

Coral Cat Shark

Also called the Indian coral catshark (Atelomycterus marmoratus), this is a very popular choice. Its pattern is a mix of dark and light dots or lines across the body. FishBase lists a maximum of 70 cm (about 28 inches), with most adults around 24 inches.

Marbled Cat Shark

The Australian marbled catshark (Atelomycterus macleayi) looks similar to the coral catshark, with white dots on a dark background and sometimes dark bands. It reaches about 24 inches and is often easier to find.

False Cat Shark

The false catshark (Pseudotriakis microdon) is a deep-sea species that grows close to 10 feet. It is plain in color and unsuitable for aquariums.

What habitat and tank conditions do cat sharks need?

Cat sharks are marine bottom-dwellers that spend much of their time scavenging the seabed, mostly at night. The group is diverse, so check the needs of your species. Coral catsharks, for example, as the name suggests, are mostly found near coastal reefs.

How should you set up a cat shark tank?

Cat sharks are not a good first marine tank. Setting up a large saltwater system and cycling it takes months. Marine tanks do need more attention than freshwater ones, though many common misunderstandings make them seem harder than they are.

Set up the tank around the species you plan to keep.

• Substrate: fine sand. Avoid sharp gravel, shells or coral rubble that can scrape the shark’s belly.
• Rockwork: live rock or smooth artificial rock with caves and overhangs. Secure it well, because sharks push and squeeze under things.
• Temperature: coral catsharks about 75-82°F, bamboo sharks about 72-78°F. Keep it stable.
• Water: pH around 8.1-8.4, specific gravity 1.020-1.025, KH about 8-12 dKH. Ammonia and nitrite at zero.
• Filtration: strong biological filtration and a protein skimmer, since these are large, messy feeders. Provide gentle flow along the bottom.
• Lighting: low to moderate. These are nocturnal fish, and they hide under bright light.
• Lid: cover the tank. Some will push out of a gap, and tank edges and glass need to be kept smooth.

What size aquarium do cat sharks need?

For a coral catshark, 180 gallons (6 x 2 x 2 feet) is the absolute minimum for a single adult or a pair, and 200-300 gallons is a more realistic target. Some keepers suggest a footprint of about 7 x 2.5 feet (250-270 gallons) for two or three adults. Smaller species such as the banded sand catshark stay under about 18 inches but are still usually kept in 180-gallon or larger tanks.

Bamboo sharks need much more. Stores often say 180 gallons is enough, but that only covers a juvenile. An adult brownbanded bamboo shark, which can grow to 3.5 feet or more, needs about 660 gallons or more with a long footprint.

Footprint matters more than height. Choose a tank with a large floor space and long, clear sides, so the shark can turn around.

What are the best tank mates for cat sharks?

Cat sharks spend most of their time on the seabed. Many are fairly peaceful but they are predators, so anything small enough to swallow, including crustaceans (one of their favorite foods), shrimp and small fish, may be eaten. Reef tanks with corals and invertebrates are risky, and the shark may knock over coral.

Suitable tank mates are fast, larger, non-aggressive fish that stay up in the water: tangs such as Yellow and Hippo Tangs, non-aggressive groupers and Harlequin Tusks. Some keepers pair them with rays, but only in very large tanks.

Avoid large predators that compete for food, like eels. Triggers, puffers and large angelfish often bite sharks and should be avoided as well.

Can you keep cat sharks together?

Yes, in a large tank. Most cat sharks are solitary in the wild but accept each other in a tank, especially when raised together. A keeper who wants a group should give each shark its own cave, keep the numbers small (one to three is a safe limit) and watch for bite marks.

What do cat sharks eat?

Cat sharks are seabed predators. Their natural diet includes mollusks, crustaceans, other invertebrates and small fish. Their teeth crush shells rather than slice flesh.

In captivity, feed meaty foods such as shrimp, squid, clams, mussels, krill and silversides. Feed after the lights go out, since most are nocturnal. Juveniles do best with small meals daily or every other day. Adults can be fed 2-3 times a week. Watch for sharks that stop eating, which usually points to a water problem or incorrect temperature. Remove uneaten food to protect water quality.

How do you keep a cat shark healthy?

Cat sharks are hardy, but they react badly to sudden changes in water parameters. A cold tank slows their metabolism, while a warm tank reduces appetite and increases parasite risk.

Change 10-15% of the water weekly with properly mixed marine salt, and test regularly. Keep the substrate clean, because skin scrapes can become infected.

Cat sharks are not prone to one particular disease, although infections are quite common. Captive sharks that don’t get enough iodine can develop a goiter, an enlargement of the thyroid. Many keepers add an iodine supplement following the product’s instructions, but check with an aquatic vet before dosing. If the shark is injured and doesn’t recover, move it to a quarantine tank and treat it with an appropriate antibacterial.

How do cat sharks behave?

Most cat sharks are solitary, though some gather in groups in the wild. They are not active chasers but may bite other fish that come too close. Most species hunt at night, and their feeding behavior is very different from that of typical sharks. Bamboo sharks use barbels, like cat whiskers, to probe the seafloor. They belong to the ground shark order (Carcharhiniformes) and stay near the bottom. Expect to see yours resting in caves during the day and moving around at night.

Can you breed cat sharks at home?

Cat sharks are oviparous, which means they lay eggs. Most captive breeding happens in public aquariums and specialized facilities, since the conditions are hard to replicate at home.

Some species, including coral catsharks, have been bred by hobbyists. Females attach eggs to substrate or objects on the seabed. FishBase gives a coral catshark maturity size of around 49 cm for males, and sources vary on the rest, so don’t rely on size alone. Hatchlings are usually around 4 inches long and start feeding soon after hatching. For most home aquarists, buying an egg or a juvenile is a safer route than breeding.

Is a cat shark suitable for your aquarium?

Cat sharks are beautiful and unusual, but they need a large marine tank, stable water and a long-term plan for the shark’s adult size. We only recommend them to experienced marine aquarists. If you are new to saltwater, start with simpler saltwater fish first.

Frequently Asked Questions

What size tank does a coral catshark need?

At least 180 gallons for one adult or a pair, which is the absolute minimum. A 200-300 gallon tank with a footprint of 6-7 feet is more comfortable and gives you room for rockwork.

Are coral catsharks aggressive?

No. Coral catsharks are shy and nocturnal, but they are predators and will eat small tank mates such as shrimp, crabs and small fish. Keep them with fast, larger, non-aggressive fish.

How much does a coral catshark cost?

Around $300 for a coral catshark in recent years, with eggs about $45-$50, though prices change often. Marbled catsharks have been listed around $80-$85 and banded (bamboo) sharks about $150-$170. Check current prices, and budget more for the tank than for the shark.

Can you keep a coral catshark as a pet?

Yes, but only if you are an experienced marine aquarist with a large tank. Catsharks are not a good first marine tank, since a coral catshark needs at least 180 gallons, stable water and a 15-20 year commitment.

What is the lifespan of a catshark?

Coral catsharks are reported to live 15-20 years in captivity, and brownbanded bamboo sharks 20-25 years. These come from keeper care sheets, not a formal study.

Do catsharks bite?

They can, but they aren’t a danger to people in practice. Catsharks may bite when handled or when they mistake a finger for food, so use a net or tongs and avoid hand-feeding. They may also bite other fish that come too close.

Have you ever thought about getting a shark? Let us know in the comments section below…