Sharks are, for many people, fascinating but feared creatures. Before his death, Peter Benchley, author of “Jaws”, regretted that his novel helped create the popular perception of sharks as monsters.
“Sharks are far more victims than villains,” Benchley said at a press conference in 2000 when he appealed to the public to support shark conservation efforts.
Regardless of the positive or negative nature of perception, however, sharks are compelling-so much so, that many people are attracted to the idea of keeping them as pets in home aquariums. The purpose of this article is to understand the roots of that desire and what it means to make it come true.
Very few of us can afford to host the kind of shark tank that would comfortably house the magnificent giants we see on TV documentaries, but there are sharks that can be raised in aquariums.
The smaller specimens are technical “shark fish”, and are more like minnows, but have the distinctive, streamlined appearance of their giant brethren.
For brackish or saltwater tank enthusiasts, small species of true sharks or Elasmobranchii are definitely an option.
Most of these sharks are less than 2 feet (0.609 meters) long. They do require large tanks, but for people who really want to live with and study these fascinating creatures, the investment in time, money, and space is well worth it.
If you’re new to aquaculture, it’s a good rule of thumb to decide on the focal point of your tank and make all the decisions based on what that fish needs.
Sharks In Ocean Vs Sharks In Aquarium
Remember that any aquarium seeks to recreate a natural environment for its population down to the smallest detail. That’s true for tropical freshwater aquariums with 20 gallons (75.7 liters) or less, and it’s equally true for 200-gallon (757 liters) saltwater tanks with elaborate filtering and skimming systems.
If you want to keep sharks as pets, don’t treat the process as something that can simply “run out and buy.” You must carefully plan each step of the ecosystem or environment you are about to create. Because a new tank must be “cycled”, two months may pass before you can introduce a single fish.
Regardless, you’re about to embark on a fantastic adventure that will give you a window into a world that humans can only visit, but never really inhabit.
Sharks literally breathe the water they swim in. We are only visitors there or if we keep these animals as pets. The first step is not to decide what type of tank you need, but what type of shark you want to raise.
Not All Aquarium Sharks Are ”Sharks”!
By choosing the type of shark you want to have in your tank, you immediately set in motion a path for all the other decisions you will make regarding equipment purchase, tank design, placement, and maintenance.
If you really want to keep sharks as pets there are two common starter species of freshwater shark fish, the Bala Shark, and the Red Tail shark
Bala Shark (Docile But Large)
The Bala shark is one of the easiest freshwater species have as a pet. They are one of several species of sharks that are close relatives of the small fish. Bala sharks are social and friendly creatures that get along with smaller fish, especially if they have been raised together.
They like to swim and school with their own species, or with any species that congregate with them.
One lovely thing about a Bala Shark is that they will often have a “best friend” of another species in the tank, a situation that is fascinating to see from the other side of the glass.
A Bala shark will grow to a maximum length of 16 inches (60.6 cm). Ideally, they can reach 24 inches (61 cm), but that’s rare in home aquariums. At a minimum, these fish need a 6 foot long (1.8 meter) tank. (Four feet, or 1.2 meters, really isn’t enough for a fish that spends the day swimming “on patrol” and loves to school.)
The moment you decide you want a Bala shark, your planning process begins to involve all of the tank-related factors the fish needs.
Start with a weight consideration. A 6 ‘x 2’ (1.82mx .61m) tank will hold 180 gallons of water (681.37 liters) and, when fully equipped, will weigh more than 2,000 lbs. (907.18 kg)
The next item on your list immediately becomes a stand enough to support that weight, and then you need to think about tank placement. That means considering both structural stability and weight-bearing issues, as well as the effect of light.
Place an aquarium too close to a source of direct sunlight, and you will wage a constant war with algae growth.
If this is the direction you decide to go, buying the Bala Shark is a $3 to $12 purchase (£2 – £8). The approximate cost of the tank the fish will need to live happily (without any of the additional equipment required) is $1,350 (£860).
Red-tailed Shark (Aggressive But Small)
If you don’t have room for a six-foot (1.82m) tank, you can choose to breed a red-tailed shark. They are also a close relative of the small minnow and are the smallest freshwater shark fish.
A red-tail shark rarely grows to more than 6 inches long (15.24 cm) and can be housed in a 20-gallon (75.7-liter) tank.
An aquarium of this size can easily be purchased at a pet retail store. They are generally available as kits, with all equipment included, for approximately $200– $250 (£127 – £159). The Red Tail Shark itself will not be more than $3– $5 (£2 – £3).
However, you should realize that by going with a red-tailed shark, you are inviting a little thug with a Napoleon complex to your tank. Red Tail Sharks fight other fish in the tank, often to death. They exhibit extreme territoriality and are bridges.
Never put a red tail shark in a tank without a cap. You will return home and find your fish supremely confident, but unconsciously suicidal, dead on the ground.
Also, you can only have one Red Tail shark at a time, as they are even more aggressive with others of their own kind.
Managing Shark Fish Aggression
When you keep shark fish or true sharks, one of the biggest challenges is managing their aggression. Some species of sharks have to be the only ones of their kind in the tank (or the only fish in the tank period).
Never introduce a shark of any kind into an existing tank without investigating its personality profile and the fish it will live with. The greatest aggression in an aquarium is on the territory. Many species, including sharks, stake out an area to call it their own and will literally defend it to death.
As a general rule, fish that exhibit territoriality are more aggressive towards their own species, which will limit the number of sharks that they can support.
The red-tailed shark we have just discussed is a perfect example. They will get along well with other semi-aggressive fish, but not with other sharks.
It is equally important to remember that as much as you want to think of your tank as a calm and peaceful environment, there is still a food chain in operation.
Many species, such as the rainbow shark, for example, get along well with fish of their own size, but they will eat smaller tankmates. Other sharks will happily eat any invertebrates that you have added to the community.
Keep in mind the fact that you are managing an ecosystem where nature’s rules apply even in the microcosm. If you introduce predators to the environment, you can hardly expect them to be more than just what they are-predators.
Aquarium Dividers Are Seldom An Option With Sharks
When a fish is being a bully, the best option is to segregate the aggressor. For smaller species, aquarists can divide the tank with a simple and clear partition. These are easily purchased for tanks up to 20 gallons (75.7 liters) but would have to be specially designed for larger aquariums.
With sharks, however, given their already considerable spatial needs, dividing available space is simply not an option in most cases. If the shark you’re trying to raise has a minimum requirement for a 6-foot-long (1.8 meters) tank, you can’t start dividing the limited space to handle the aggression.
If you really want to keep sharks and fish smaller and more compliant, it would be much better to serve you to maintain a large shark tank and a smaller tropical tank.
However, it is possible that when you understand the degree of work involved in maintaining an aquarium large enough to accommodate sharks, managing the personal interactions of its inhabitants will not be on your “trouble” list.
Things To Understand Before Keeping Sharks In A Home Aquarium
Three factors will guide your decision about keeping sharks in a home aquarium:
- Species resistance
- Availability of sharks
- Compatibility of sharks
Resistance refers to how easily a species of shark can adapt to live in captivity.
This is rarely a problem with shark fish, but it can be a problem with true sharks. Many larger sharks refuse to eat when presented with a new tank and must be enticed with special treats.
Availability refers to the ease with which a given shark can be obtained.
Shark-like fish are available, but some true sharks can be difficult to acquire and expensive to purchase.
Tank-raised Marbled or black-banded Bamboo Cat Sharks retail for $60 to $70 (£38 to £45), but a Port Jackson shark sells for $300+ (£194) depending on size.
Also known as Horn Shark, this particular species, which reaches 5 feet long (1.52 meters), needs a 1000 gallon (3785.4 liters) aquarium.
Compatibility is not just a reference of how the shark will get along with other fish, but also with any invertebrates in the tank.
Shark Tank By Type Of Water
Shark fish and true sharks are kept in three basic types of aquariums:
- Freshwater aquarium
- Saltwater or marine aquarium
- Brackish aquarium
While freshwater aquariums can be quite large, most shark-like fish are not, they remain below 2 feet (61 cm) in length.
“True” or marine sharks are kept in saltwater aquariums, requiring a much more complex understanding of water chemistry and a wide range of water movement and filtration equipment.
Brackish aquariums are the intermediate range between the other two environments and seek to replicate places where rivers meet the sea. In estuaries and similar points of convergence, species thrive that pass back and forth between fresh and saltwater environments.
Among aquarists, brackish tanks are considered the logical springboard between marine and freshwater tanks.
Introduction To Basic Water Chemistry
Water chemistry is a topic of endless discussion among aquarists, to the point that it almost seems like an obsession for those who are not “informed”.
However, if you stop and consider yourself responsible for keeping the liquid atmosphere your fish breathe, the “obsession” suddenly becomes quite clear.
Without good water, your sharks will die. The longer you work with a tank, the more you will understand the tests necessary to maintain optimal conditions.
As a minimal introduction to this chemistry, there are three steps you should be familiar with.
- Per Hydrogen (pH)
- Carbonate Hardness (KH)
- Specific Gravity (sg)
Per Hydrogen (pH): Most people have a basic understanding of pH in relation to acidity. The lower the pH level, the more acidic the water is.
A higher pH means that the water is basic (contains more alkaline).
Expressed on a scale, pH 5 is slightly acidic; pH 7 is neutral and pH 8 is basic (alkaline).
The specific measurement is the balance in water between hydrogen (H +) and hydroxide (OH) ions.
- Saltwater has a pH range of 7.5 to 8.4
- Freshwater has a pH range of 6.5 to 7.5
- Brackish water has a pH of 7.5 or higher
Carbonate Hardness (KH): This measure can be confusing. It is an expression of the alkalinity of water, which is not the same as “alkaline”.
Alkalinity quantifies the ability of water to act as a “buffer”, absorbing and neutralizing acid. The higher the KH (the higher the alkalinity of the water), the less likely it will be to experience changes in the pH level. Therefore, a higher KH level means more chemically stable water.
Specific gravity (sg): In a saltwater aquarium, specific gravity is the measure of relative salinity compared to pure water. The measurement is taken with a hydrometer or a refractometer.
The specific gravity of natural seawater varies by location in a range of 1,020 to 1,030. For a saltwater aquarium, the usual goal is 1,022. It is important to establish a range and not vary widely.
Most creatures will adjust to any specific gravity within reason, but not fluctuations.
Cycling Your Fish Tank
Regardless of the type of water you are maintaining, the nitrogen cycle must be established in the tank before fish are introduced. This is not an “instantaneous” process and requires the cultivation of biological processes that create water with enough bacteria to keep marine species alive in a closed environment.
The steps in the cycle are as follows:
- Your fish produces waste materials.
- Waste materials produce ammonia in water, which is toxic to fish.
- Ammonia feeds the nitrifying bacteria present in the water.
- Bacteria eat ammonia and produce nitrite.
- Nitrite is in turn eaten by other bacteria that produce relatively harmless nitrate.
The toxic effects of ammonia produced by waste materials in water are canceled out by a biological food chain.
The aquarium water is filtered and part of the water is changed regularly to control nitrate levels.
The nitrogen cycle, however, preserves the chemical balance of the water. Aquarists frequently test tank water and monitor its quality to preserve this balance.
Depending on how this cycle is initially established, proper conditioning of the water in your new tank can take 6 to 8 weeks.
Basic Tank Cleaning Procedure
Try to think of your aquarium as a system that works smoothly. Every day, while feeding the fish, or just observing their interactions, take the time to evaluate how each component of the system works.
Look And Listen
Immediately evaluate anything that does not sound or seem correct. Over time, you will become familiar with the noises your equipment makes. If a filter starts making a strange sound, don’t let it go. Find out why.
Not maintaining the correct water quality is the number one cause of death in aquarium fish.
How do your fish behave?
Are they eating?
Do they look healthy?
Are they exhibiting any unusual behavior?
If you see something that doesn’t seem right, run a water test and examine people closely for any signs of disease, which often manifests with blemishes, decreased discoloration, fungal growth, or even rot.
Make A Schedule
In addition to constantly monitoring water quality, create a routine to:
- Partial water changes
- Gravel Vacuuming
- Filter service
- Algae removal
- Comprehensive water tests.
Computerized tank monitoring is extremely helpful in keeping up with these tasks, but it is not a substitute for the actual manual labor involved.
That depends on you.
Water Changes And Gravel Aspiration
Although the frequency of water changes will vary depending on the tank configuration, consider the following general guidelines:
- 25% water change every two weeks
- Include a partial vacuuming of the gravel to remove debris in the procedure.
- When you change the water, unplug the heaters, powerheads, power filters, and power pumps. Also, remove the ornamentation to make cleaning the gravel easier. Don’t forget to shake the substrate to loosen the embedded debris.
- Depending on the type of vacuum you buy and the power capacity in relation to the size of your tank, expect to pay $50- $100 (£32- £65).
- Always make sure that the water you are putting in is the same temperature as the existing tank water and that it has been dechlorinated and is subject to any other required treatment, including adding sea salt if you are working with a saltwater aquarium.(Note that premixed saltwater must be aerated and agitated for 24 hours prior to addition to the tank to ensure correct SG (Specific Gravity) has been achieved.)
- If necessary, scrape and remove any algae that grow on the sides of the tank.
- Always be sensitive to the number of nitrifying bacteria you are removing during water changes. It is imperative to maintain the nitrogen cycle in your tank.(Note that there are many, many products and tools available to help maintain aquariums. Apply the same level of research to select this equipment. Successful tanks depend on good water quality, which is the goal of regular maintenance and comprehensive).
Which Shark Is ”Ideal” For Your Home Aquarium?
“Ideal” is a relative term. What you can afford in terms of tank space, time, and commitment to shark husbandry is ideal for your situation, but it might prove impossible for another hobbyist.
That being said, if you can choose within these parameters, your chances of successfully keeping the real sharks in a home tank are greatly increased.
- A 180 to 500-gallon tank. (681.37 to 1892.7 liters)
- Selecting a small, tame shark that is well suited to captivity and will eat.
- A shark that puts on satisfactorily in the tank.
Remember that tank size is always the dominant consideration. Experts say a good rule of thumb is to take the maximum adult length of the shark you are interested in and multiply it by 3 to get the minimum length of the tank.
A two-foot x 3 shark = 6 foot tank (.609 meters/1.83 meters)
In “Sharks For The Aquarium And Consideration For Their Selection,” published in 2010 by the Florida Cooperative Extension Service, the University of Florida Institute of Agri-Food Sciences, authors Alexis L. Morris, Elisa J. Livengood, and Frank A Chapman chose five true sharks as “ideal” for marine amateurs.
- Bamboo shark (white-spotted and brown-banded), at a length of 3.4 feet (104 cm)
- Coral Catshark, at a length of 2.3 feet (70 cm)
- Horn Shark, at a length of 4 feet (120 cm)
- Leopard shark at a length of 4.9 feet (150cm)
- Port Jackson Shark, at a length of 4.4 feet (137 cm)
But remember, keeping sharks is a numbers game. If you want a 5 foot (1.52 meter) leopard shark, you will technically need a 15 foot (4.57 meter) aquarium or basically a swimming pool.
When this question was asked to enthusiasts at Yahoo Answers in 2011, an aquarist expert offered these specs for a Leopard Shark tank at home.
- 12 ‘long (3.65 meters)
- 12′ wide (3.65 meters)
- 4 ‘deep (1.21 meters)
- 4,208.8 gallons (at 8 lbs per gallon) 33,670.4 lbs. or 16.8 tons/15.24 metric tons)
Conservatively, the tank would only cost $15,000 / £9,725.
Fortunately, there are other options that will still satisfy enthusiasts’ desire to keep sharks.
Feeding Your Pet Shark
True sharks will not thrive on a pure protein diet like shrimp or smaller fish. Expect to supplement your shark’s diet with tablets or gels that provide essential vitamins and minerals.
Mazuri, a company that specializes in exotic pet food, manufactures a line of dietary supplement products for sharks and rays.
As an example, 2 pounds. (.9 kg) of the Mazuri product, Vita-Zu Shark / Ray Tablets provides water and fat-soluble vitamins and minerals and helps decrease the risk of iodine deficiency. It sells for $110 (£71).