The most commonly kept sharks are bottom-feeding or shallow-water fish. Their prey includes primarily crustaceans such as crabs, hermit crabs, shrimp and small lobsters, bivalves such as scallops, mussels and clams, and worms as well as some small fish. Most sharks can be trained to accept foods such as earth worms, shrimp, squid, clams or pieces of fish from a feeding stick or out of the hand. Just be careful if hand-feeding; they may accidentally nip fingers! It is also important to avoid large open-water fish such as tuna and swordfish when choosing food for your shark. These types of fish usually contain mercury in their muscle tissues that can poison your fish.
Sharks are enthusiastic eaters, but be careful not to overfeed! Most sharks usually eat large meals, with a day or so interval between meals, and can actually suffer from feeding too frequently. Thus, it is only necessary to feed them in intervals, such as on an every-other-day basis. In order to determine if your shark is being fed appropriately, monitor its appearance. The shark should be neither obese nor emaciated. Look at the head and body: the skeletal structure should not be visible, and the body should be sleek, not bulging between feedings (unless it just ate).
In order to stay healthy and grow properly, sharks need the correct amounts of fats, proteins, vitamins and minerals in their diet. For this reason, it is important to feed a large variety of foods on a regular basis. Different foods have different amounts of proteins, fats and other nutrients that must be kept in balance for the shark to survive in captivity. Water-soluble minerals are normally present in salt mixes. Regular water changes will keep these minerals in adequate supply. Amino acid and vitamin supplements can be added directly to the food before feeding if necessary.
Be sure to remove uneaten food from the tank immediately to help prevent stress from poor water quality.
Sharks are often the victims of a bad reputation. They are not the stupid eating machines people often characterize them to be. Sharks are in fact very intelligent creatures, and can even be trained in a similar manner to dolphins and whales. Those sharks that are commonly kept in home aquaria are relatively docile fish that can be kept with most peaceful species that are too large to be consumed. They may be aggressive with other sharks if territory or food supply are limited, but are otherwise well-behaved toward suitable tank mates. Though most sharks have rough skin that is difficult to damage, aggressive tank mates can actually stress or injure a shark to the point of death. Thus, care should be taken when choosing tank mates for your shark.
Sharks have cartilage instead of bone, which makes it more difficult for them to maneuver in small spaces. Thus, a very large tank is necessary to keep them healthy and stress-free in captivity. Provide an aquarium that is at least the same width as the maximum size of the shark, and two or three times the length of its maximum size. Width and length are much more important that height when choosing an aquarium for most sharks. However, open-water species should be given even larger enclosures that are deep and long as well as tall.
When hiding or resting, some sharks prefer to enter rock crevices or caves. If this applies to your shark, it is important to provide at least one cave or similar hiding place so that the shark will have a place where it feels secure. This is a great stress reducer. Be sure that any caves made of multiple rocks are secure, as many sharks will dig around the rocks to make a comfortable space. An unsecured structure may topple over and crush a shark, usually injuring or killing it.
Some species of sharks dig into the substrate when searching for food. If this applies to your shark, provide fine, smooth-edged substrate that will not scratch or abrade the snout.
Some sharks are nocturnal fish that are more active in the night time hours, or prefer deeper or murkier waters that are poorly lit. If this applies to your shark, provide subdued lighting to encourage normal behavior and minimize stress.
Some sharks are open-water swimmers that are very active. If this applies to your shark, be sure to provide the largest tank possible, and keep the tank either minimally decorated or free of any ornaments to provide maximum swimming space.
Water quality is an extremely important factor in the health of any shark. They are extremely sensitive to poor water conditions and inadequate tank space. Frequent water changes and consistent monitoring of water conditions
are a must! Build-up of nitrates can cause serious health problems or even death. Tank space is important not only for the mental health (that's right!) of a shark, but to maintain water quality, as well. Larger tanks tend to stay in balance more easily, and reduce stress. A protein skimmer
and an efficient biological filter
are important equipment to maintain good water quality. Sharks are also very sensitive to stray electrical currents, so a grounding probe
is a wise investment to eliminate any stray current that may be emitted by electric aquarium equipment.
It is important to choose tank mates that will not injure or stress your shark. Some suitable invertebrate tank mates include slipper lobsters, spiny lobsters, linkia stars, brittle stars and pencil urchins. Keep in mind that invertebrates may end up as food at some point. Appropriate fish tank mates include cardinals
, batfish, goatfish
, some eels
, groupers, snappers
, and jacks as well as cleaner fish and any other specimens that do not nip or chase the sharks. Avoid very territorial or nippy animals such as angels, puffers or triggers.
Species of True Sharks
Brownbanded Bamboo Shark
— Chiloscyllium punctatum
41 inches (3.5 feet)
Japan to Australia, India to Indonesia
Docile to Semi-aggressive
Temperature: 72 to 82 degrees
Though this shark is commonly called a cat shark, it is actually a bamboo shark of the family Hemiscyllidae. It is an attractive fish that is white with black vertical bars as a juvenile. The adult's coloration fades to beige with dark brown bands. The body is slender, and the snout is equipped with barbels which are used to detect prey. It prefers rocky reef areas, where it hunts worms, crabs and shrimp. It sometimes digs to find burrowed prey. A nocturnal species, it is usually inactive during the day. It is a relatively hardy and small species, and so is a good candidate for captive keeping. They have also been known to reproduce in captivity. Tank size should be not less than 200 gallons.
— Hemiscyllium ocellatum
42 inches (3.5 feet)
Australia and New Guinea
Temperature: 72 to 82 degrees
This is a hardy shark that is a close relative of the more common brownbanded bamboo shark. It is cream colored with small dark spots. It has an elongated body that is well adapted for maneuvering in rocky areas. The head is slender and the snout is slightly elongated. It prefers shallow inter tidal areas and rocky reefs. It hunts by searching rock crevices and digging in the substrate for worms and crustaceans. Its small size makes and its ability to maneuver in smaller spaces makes it an ideal candidate for captive keeping. Epaulette sharks are territorial in captivity, however, and may behave aggressively toward other sharks, especially those of their own species. Tank size should be at least 250 gallons.
— Atelomycterus macleayi
24 inches (2 feet)
Northern and Western Australia
Temperature: 72 to 86 degrees
This shark is a true member of the catshark family, Scyliorhinidae. It is light brown with small white and black spots covering most of the body. Additionally, seven faint gray bands adorn the dorsal side. This shark inhabits tidal flats and pools, hunting primarily crustaceans and worms. This shark is timid and nocturnal, and so requires ornaments such as caves and rock crevices for day time resting places. It is extremely docile, and must only be housed with peaceful fish. Its relative hardiness and small size make it an ideal candidate for captivity, but is a less commonly seen species in the aquarium hobby. A minimum tank size of 100 gallons is recommended.
Port Jackson Shark
— Heterodontus portusjacksoni
67 inches (5.6 feet)
Southern and Eastern Australia
Temperature: 57 to 70 degrees
This shark is wide-bodied with large fins. Both dorsal fins are equipped with a spine at the front base. It has a large head with ridges over each eye, and a pig-like snout. Port Jackson sharks are beautifully marked with dark lines on a cream to gray background. They are nocturnal, hiding in caves during the day, and emerging at night to feed on fish, urchins, sea stars and snails. Port Jackson sharks seem to frequent the same areas in their natural habitat, so they may set up a resting territory in the home aquarium. This is a relatively hardy species, but is easily intimidated by aggressive tank mates, especially when acclimating to a new environment. A minimum tank size of 750 gallons is required.
Gray Smooth Hound Shark
— Mustelus californicus
47 inches (4 feet)
Northern California to the Gulf of California
Semi-aggressive to Aggressive
Temperature: 52 to 70 degrees
This shark has a more slender version of the stereotypical shark appearance. It is silver-gray and streamlined for open water swimming. Its tail has a notch. This shark ventures in both shallow and deep water areas, feeding primarily on crustaceans and a few fish. It can even swallow hermit crabs shell and all! It will occasionally dig for prey in the substrate. Gray smooth hounds can be aggressive with other tank mates, and may even try to eat those that are relatively small. It can also bully smaller or more timid sharks, so be sure that there are both plenty of food and plenty of swimming space if keeping multiple specimens. Smooth hounds are very hardy, and adapt well to captive care. However, due to their extremely active nature, they require a very large swimming area that is free of obstructions. A minimum tank size of 2,000 gallons is required.
Brown Smooth Hound Shark
— Mustelus henlei
37 inches (3 feet)
Northern California to the Gulf of California, Ecuador and Peru
Semi-aggressive to Aggressive
Temperature: 52 to 70 degrees
This shark is similar to the gray smooth hound, but is smaller and has frayed dorsal fins. The body is copper to gray in color, and its tail has a notch. It also feeds primarily on crustaceans and a few fish. It can even swallow hermit crabs shell and all! It will occasionally dig for prey in the substrate. Gray smooth hounds can be aggressive with other tank mates, and can also bully smaller or more timid sharks. Thus care must be taken when choosing tank mates. Smooth hounds are very hardy, and adapt well to captive care. Due to their extremely active nature, they require a very large swimming area that is free of obstacles. A minimum tank size of 1,500 gallons is required.