Owning a pond, however, is an entirely different experience than owning a small, in-home fish tank. While there is a minimal amount of planning that goes into building a freshwater tank, a pond requires significantly more, especially if you build the pond yourself. Building a pond is a backyard renovation. It requires you to sit down and plan, as you will be making long-term changes to your property. You may want to consider hiring a professional to design and build your pond for you.

A regular in-home aquarium, however, simply involves you heading over to your local pet store. Most if not all of the supplies needed to build and maintain a moderate aquarium in your home can be found in the pet store right near their fishes and aquariums. Pond supplies often require drips to specialty pond stores, home improvement stores, and pet stores for supplies and fish.

Caring for your fish in either situation changes little. Most pond fish, such as koi, have specific dietary needs that are easily met through pellets or flakes that can just as easily be fed in a pond as they can be in an aquarium. Additionally, in colder climates there is no need to feed your pond fish over the winter as they semi-hibernate in the warmer sections of your pond.

Both ponds and aquariums require water changes in addition to adequate filtration and ponds tend to become stopping points for local wildlife with can significantly dirty the waters beyond what your filter can handle, requiring you to remove your fish from the water, drain your pond, and completely clean it out. An aquarium rarely requires such drastic changes as even at its worst a good scrubbing with an algae pad is often sufficient for removing the worst algae while a water change will bring the situation back under control.

Predators are not a concern, generally, when dealing with an aquarium. Pet stores sell lids that will tightly clamp onto the top of your tank, protecting the fish from outside intruders and preventing them from jumping out where predators, such as cats, can get a hold of them. A pond, however, often draws predators that you least expect into your backyard: birds, raccoons, and possums to name a few. This can be a problem, not only for your fish but for other pets that you may have in your home. Netting and other anti-predator precautions must be taken once your pond is established to prevent your new backyard ecosystem from being destroyed.

Though neither option should be taken lightly, building a pond in your backyard should be carefully considered. Not only will it house large fish dependent on you for their well-being, it will renovate your landscape and requires a pretty hefty investment.

Despite the example set by Dory from Finding Nemo, fish are capable of rather impressive feats of memory and have been shown to recall information up to five months after being introduced to stimuli. This has far reaching implications for the farming industry. They have discovered that after training fry for a month to respond to a sound, they could release the fish into the oceans to live normal lives out in the seas. Four to five months later, they could play the same training sound and the fish would display the same response – in the case of the fish trained to respond at feeding time it meant that those fish that survived life in the ocean returned to the same place for food as they had when they were fry. If this can be successfully implemented, it means that many of the negative impacts of fish farming can be avoided by letting the fish develop in the wild and then calling them home when it’s time to harvest.

Is it surprising, then, that fish are able to recognize predators and prey? It is not at all unheard of for a fish to recognize a previous predator. After all, carp will avoid a fisherman’s hook for up to a year if they escape!

Perhaps the most interesting impact that fish memory has is their ability to morph prior knowledge into excellent marketing skills. Take, for example, cleaner fish, those fish that survive by nibbling parasites off larger fish that would normally be seen as predators. These cleaner fish have been observed in their natural habitat to “market” themselves to potential clients. While in the midst of cleaning a current client, they will improve themselves if a larger client is in the vicinity in the hopes that their “superior” cleaning skills will encourage the larger patron to visit their cleaning station rather than that of their competitor.

While their memory is not up to the same level as that of humans, fish can certainly compete in the memory market. With patience and determination, you can even “train” your fish to respond to a command or two.

Before you can examine how a fish breathes, however, you must understand what a fish is. A fish is not a mammal and as such does not require atmospheric oxygen like we do… with one exception: the labyrinth fish. Fish are cold-blooded vertebrates, meaning they have no internal temperature control and their skeleton is found inside their skin, unlike bugs whose skeleton is found on the outside. Fish are found exclusively in water, so you won’t see them on land unless they’re safe in a fish tank. Because they live their entire life in the water, they have special organs that help them to breathe. Do they breathe oxygen? Absolutely, it is just different than the atmospheric oxygen that we breathe.

All fish follow the same basic steps in breathing. Fish breathe by inhaling water through their mouths and pumping it out of their gills. The gills of a fish are quite fascinating and play a critical part in breathing. The outer portion of the gills is called the operculum and it plays in harmony with the mouth; when the fish’s mouth is open, the operculum is closed, but then the mouth is closed, the operculum is open. This helps to create a good vacuum when breathing and forcing water over the gill rakers.

The gill rakers are an important part of the breathing process. They filter the water before it reaches the gill lamellae, removing any random particles of food or dirt that have gotten mixed into the water while the fish was inhaling.

The gill lamellae are critical in helping fish breathe. These small, comb-like filaments are covered in tiny capillaries. They give the gills more surface area with which to absorb oxygen. These filaments are very delicate, allowing water to move smoothly in and out of the gills and makes the gill rakers so important. If a random food particle smashed into the lamellae it could cause a lot of destruction and make it difficult for the fish to efficiently filter oxygen from the water. The small capillaries filter out the oxygen and carry it into the blood stream just like the capillaries in our lungs do! The used water is then pushed back out through the operculum and into the tank or ocean. In a system such as a fish tank it is important that something like an air stone is used to constantly re-oxygenate the water or the fish will suffocate!

Labyrinth Fish -

Labyrinth fish must also be discussed as they are a common aquarium addition and have additional needs. The labyrinth organ is found on the top of the head and is critical in helping these fish breathe. Fish with a labyrinth organ, such as Bettas, must have access to the surface of the water. While they breathe regularly through their gills, they will suffocate if they do not have access to atmospheric oxygen as well.

Underwater Breathing

Alternative Air Source – Kept in case your primary air source fails or your diving partner needs air. It is also called an Octopus.

Cylinder – Also commonly called a tank, it is used to carry the compressed breathing gas or air. They are made out of aluminum with the air compressed to 3000psi/210bar.

Regulator – Regulators are used to control how much gas is used at a time in order to ensure that sufficient air is maintained and air is not wasted.

Face Mask – A full face variety used for scuba diving. It seals the whole face from the water and contains a mouthpiece that provides the diver with air. It allows the diver to see, provides protection from cold or polluted water or dangerous fish, and allows for secure breathing at great depths from the surface.

Protection from the Elements

Suit – A full body protection that keeps you warm and secure in deeper, cooler waters. Most scuba divers will find a wet suit to be sufficient for their diving needs.

Diving Boots and Gloves – A must if you are hunting your own fish, these provide protection against bites, stings, and scratches. You should never hunt fish without these protections.

Safety Helmet – Separate from the face mask, the safety helmet provides additional protection and may come equipped with a built-in light at the forehead.

Swimming Like the Fishes

Backplate – The structure that links the wing and diving cylinders together with straps that secure the scuba set to the back of the diver.

Buoyancy Control Device (BCD) – The device that contains the inflatable bladder used to adjust the diver’s buoyancy underwater. It is an integral part of the harness system.

Fins – Much like the fins of the fish you’ll be hunting, these fins help you to move quickly through the water and to hover or tread water more effectively. They attach to the feet and boots.

Finding Your Way

Depth Gauge – Allows the diver to monitor depth and decompression requirements. Some digital depth gauges are able to indicate ascension rate as well.

Diving Watch – A watch that continues to work while underwater and is used in conjunction with a decompression table in order to avoid decompression sickness.

Compass – A normal compass, suitable for use underwater to help you navigate.

Dive Computer – Used to help manage decompression, ascension rates, and oxygen consumption. They can be found in watch form or HUD-like form with the computer relaying information to a screen in the mask.

Submersible Pressure Gauge – This device, also known as a contents gauge, is used to show the diver how much air is left in the tanks.

Distance Line – These should be used in murky water as they help to guide the diver back to their starting point when visibility is low.

Talk to the Other Divers

Slates and Pencils – Used for communication underwater and to keep records during the dive.

Flashlight/ Torch – Used to help provide additional visibility during night time dives or in murky waters. Can also be used to help signal other divers.

Personal Tools

Knife – Used for protection, to cut lines and nets, to pry, or to dig.

Camera – Used to take pictures of the fish while underwater. Underwater video cameras can be an excellent way in which to study your potential fish before attempting to catch them.

Sure, owning fish is a bit less work than say owning a dog that has to be walked every day or a cat that needs its litterbox changed every hour. In addition, fish don’t need to be groomed (generally) and have easy to meet dietary requirements (sometimes). But they still require regular water changes, heaters, filters… the list grows every time you add a fish to the tank. Even Betta fish, often seen in bowls on receptionist desks, have specific needs and requirements that your friend may not be willing or able to commit to at this point in their life.

Consider, for a moment, the goldfish. The goldfish is the most common fish sold in the aquarium business. There are hundreds of varieties and styles of goldfish available and many of them are hardy fish tank companions. They don’t require a special tank heater and are happy to eat flake food. What could be difficult about owning a goldfish? Waste! Goldfish have large appetites and produce incredible amounts of waste that must be filtered constantly. In addition, this means that regular water changes have to happen every 10 days in order to keep them at optimal health. Now imagine that this goldfish that you purchased for your friend is rather long-lived… You’ve saddled your unwilling friend with a fish that requires a water change and tank cleaning every 10 days and can live easily for 20 years. That means your friend could end up doing 730.5 tank changes just over the lifetime of one or two goldfish! Nothing says friendship like the gift of a reoccurring chore!

If your heart is set on helping your friend achieve their dreams of being a stay-at-home aquarist, take some time and talk to them about it. Avoid picking up fish on the spur of the moment and instead research fish with your friend and offer to buy one or two of their favorite type as a gift if your friend decides this is what they want to do. Never surprise a friend or distant relative with a pet!

Adding pets to the family, however, is slightly different. If your child wishes to own a fish, consider for yourself if YOU want the hassle of raising a surprise pet. Remember, children have to learn responsibility and owning a pet means that most of the responsibility for its health and wellness with fall on you. Take your own needs and desires under consideration. Do YOU want to handle changing the water? Do YOU want to handle cutting up fish meat for your carnivorous fish? Can YOU afford the dietary needs of the more extravagant fish that your children may want to add to your tank?

Pet ownership should never be the result of an impulse purchase. Remember, animals have no voice; they rely on us to provide them with appropriate care and companionship.