This is the jumping behavior that you really can, and should, do something about. If something in your pond levels is wrong enough, your fish might go looking for a way out. Grab a test kit and try to figure out what’s wrong. If your pond composition is fine, it could also be fear of predators. Make sure that your pond has enough space for your koi to hide from time to time, or they’ll be uncomfortable in the water and may look to escape, and if you’re building a new pond, keep in mind that koi love deeper water that lets them hide from predators. Sometimes koi also get uncomfortable in unusually warm pond water in the heat of summer and jump. This is especially common in shallower ponds in full sun in the South. Adding a bit of shade to some of your pond might be a good idea, and, again, giving your koi somewhere to hide from the sun while in the pond is a good idea. Finally, koi sometimes get uncomfortable and jump because of an overcrowded pond. Always make sure that you have more room than you need when adding new fish to your pond.
Why do my Koi jump?
Koi jumping out of the water can be really cool to see. However, it’s definitely not always a good thing. When a koi jumps out of the water, it runs the risk of hurting itself on the water surface, plants, or the rocks at the edge of your pond. Butterfly koi are especially susceptible to injury like this to their fins. The fish even run the risk of beaching themselves outside of the water, which can be fatal. That being said, jumping koi isn’t always a bad thing by any means. Often, it just depends on why your koi happen to be jumping. There are three main reasons why your koi might be jumping.
Jumping is fun
This is the main reason why koi jump. Many animals, fish included, simply enjoy jumping. If your fish are particularly jump-for-joy-inclined, there really isn’t much that you can do about it, other than trying to minimize the damage that they can do to themselves (though koi that are jumping for pleasure are far less likely to injure themselves). Carefully placed netting can help with this. Otherwise, enjoy. It’s adorable.
This jumping behavior is most often seen by koi that are new to their environment. Koi are fairly smart fish, and as such they like to know their surroundings. Part of this involves exploring the outer limits of their pond. You’ll most often see new koi jumping at the waterfall or skimmer areas. Temporary netting can prevent injury with new fish, and keeping an eye on new fish for a while after introducing them to a new pond is a good idea for many reasons, jumping behavior included. Your koi might also start back with the aerial exploration in spring or after major changes to their environment (such as new plants or waterfalls). The last reason why they might go exploring a pond that’s already familiar is because they’re hungry. Try feeding them a bit more.
Why Should You Add Submerged Plants Into Your Pond?
Many pond owners overlook submerged plants because they don’t provide the visual appeal of surface plants such as hyacinths or water lilies. However, there are a number of key benefits that submerged plants will bring to your water garden or pond, and below are some reasons you should consider adding them.
Submerged Plants Defend Your Fish Against Predators
Certain species of fish such as Koi can be very costly to acquire, and the last thing you want is for them to end up in the stomach of a predator such as a cat, raccoon or bird. Submerged plants give Koi fish the ability to hide whenever they detect predators. The fish will swim beneath the plants and can also use them for camouflage.
The root leaves and stems of submerged plants provide the fish with ideal locations for placing their eggs. Once the eggs hatch the plants will protect them while offering a food source and a comfortable domicile. A good plant for this purpose is the Vallisneria, which has the appearance of a ribbon. It will provide grass like meadows beneath the water’s surface.
Submerged Plants Provide Oxygen
Underwater plants are sometimes known as oxygenators, and this is because they produce oxygen naturally. It is a byproduct of the process known as photosynthesis, and is essential for the healthy functioning of the pond and all the animals within it. When submerged plants are combined with a good aeration system the result will be water which is significantly cleaner.
While there are many underwater species of plants, some of the best for water gardens and ponds include Red Ludwigia, Red Stemmed Parrot’s Feather, and Vallisneria. While the installation of such plants may seem complex, they are not. You will want to make use of planting baskets, oxygenators and plant media. Each plant basket should be placed at the pond’s bottom, or it can also be placed on a plant shelf along the pond’s side walls.
The purpose of these plant baskets is to prompt the roots of the plants to extend outward and acquire nourishment while containing the plant and preventing the fish from eating the roots. Plant baskets come in different sizes so it is important to choose one which is best for your pond. The best plant baskets have sides made from mesh which allow for nourishment from the water. Plant baskets are not always rounded and can be purchased in less common shapes such as square or even the shape of a kidney.
Ponds differ in shape and you will want to select your plant basket accordingly. The plant basket allows various species of underwater plants to be installed in various areas of your pond with ease and low cost. While surface plants will provide your pond with visual appeal, it is the submerged plants which will keep the fish protected while maintaining the health, vitality and longevity of the pond itself.
Causes of Koi Staying in One Spot
1) Poor water quality
One of the leading causes of koi immobility is poor water quality. High concentrations of nutrients can stimulate pathogenic growth in your pond and reduce oxygen levels. This can be indicated by strange behavior from multiple koi, although there will always be one or two to first show signs of ill health. Fish with compromised immunity are rarely able to survive through bouts of poor water conditions and will likely need special treatment or medication.
Once you spot a weak fish, check your water parameters as soon as possible. Make sure that your pond’s ammonia (NH3), nitrite (NO2), chlorine, and pH levels are within the normal range. Anything above zero for both ammonia and nitrite concentrations can indicate that something is off-balance or your filter is faulty. Fish that are subject to ammonia poisoning may choose to isolate themselves at the pond bottom. Peer closely at the fins and most delicate parts of these fish, as they may begin to display streaks of blood or erosion.
Your pond’s pH level should be between 7.0 and 8.0. Prolonged exposure to pH levels above or below this range can result in health problems due to metal toxicity (heavy metals dissolve in acidic water), hypoxia, or alkalosis. These can all cause lethargy and immobility. Make sure to check for water hardness levels as well. The GH (general hardness) of your pond water should be higher than 10˚dH, and the KH (carbonate hardness) should be higher than 6˚dH.
If any parameters are outside the normal range, your pond may need a heavy water change. It may also need to be supplemented with biological filters, mineral additives, or pond plants.
2) Low oxygen levels
In a koi pond, dissolved oxygen (DO) levels should be maintained at 6 ppm (6 mg/L) or above. Anything below this value can cause koi hypoxia and increase levels of harmful nutrients. Over time, poor oxygenation can lead to dramatically worse water quality. When ignored, these eventually have a combined effect that can complicate diagnoses of koi diseases. Ensure that it does not reach this point by keeping an eye out for early symptoms of hypoxia. These include sluggish behavior, lack of appetite, congregations near a water source (such as an air stone), gasping for air at the water’s surface, and pale gills.
Extended exposure to DO levels below 6 ppm can compromise koi immunity by lowering rates of tissue repair. It can also stimulate the outbreak of bacteria and parasites that may severely reduce rates of fish growth and survival. It is essential to routinely measure your pond’s DO levels as they can fluctuate as a result of increased fish density, salinity, and water/ambient temperatures.
Use a reliable DO meter or test kit, and make sure to test for DO levels at the water column and not just at the surface of your pond. If you find that these values are always insufficient, you may need to invest in more mechanical aerators, add oxygenating aquatic plants, or reduce your fish density. If you make use of electric air pumps, do check these for wear and tear and have extra parts on hand to prevent drops in DO. Even short periods of oxygen deprivation can be extremely detrimental to koi.
3) Parasites & diseases
Like all other animals, koi that are ridden with parasites and diseases are less likely to have the energy to move around. Parasites usually lead to infections and disease (and vice versa). When affected fish stay put in one place, it is likely that their swimming organs have been compromised. Check for these early signs of parasitism to prevent irreversible damage:
- cloudy skin as a result of mucus production
- lethargy or listlessness resulting in immobility (commonly shown by fish sitting at the pond bottom)
- redness of the skin and fins
- pale gills
- cloudy eyes
- distress on the pond’s surface
These symptoms can be caused by a wide variety of diseases and parasites. You will likely have to fish out your affected koi and check their exposed body parts for physical signs of infection. A mucus or skin scrape sample may also be needed to diagnose the occurrence of microscopic microbes. Many fish parasites, such as Trichodina and Ichthyophthirius multifilis, may be too small to be seen with the naked eye and can remain undetected as your fish grow weak.
Another disease that may cause your koi to stay on the bottom and struggle to move around a pond is swim bladder disorder. This can either be permanent or temporary and will require close observation. Cooked or frozen green peas are common remedies to the temporary form of this disorder and should work in a few hours by reducing the pressure on your fish’s bladder. The permanent form will likely require professional treatment and involve surgery.
4) Fright & tiredness
When frightened, koi tend to panic or frantically swim towards areas where they can hide. They can easily hurt themselves or other fish in the process. Depending on the severity of their injuries or on their state of stress, koi will need some time to recover and may require additional treatments. Significant stress after a moment of fright can result in flashing behavior or koi crashing towards the bottom or sides of your pond. This can cause them to grow extremely exhausted.
When the source of fright is removed, they may stay immobile along the bottom of your pond for some time, but they should soon go back to swimming normally. Provide your koi with more shelter or safe hiding places to prevent injury. This can come in the form of herbaceous floating plants or smooth-edged man-made shelters that can sit along the bottom of your pond.
Other causes of exhaustion are significant water change, relocation from one body of water to another, and mating/spawning. Acclimatizing to new conditions and recovering from high-energy activities may cause koi to grow extremely weary, especially if water parameters are not optimal. You can opt to treat your pond water with additives to remove heavy metals, ammonia, and chlorine to aid in recovery. This would be highly beneficial for fish that have to adapt to new water, especially when colonies of healthy pond bacteria are yet to become established.
5) Winter temperatures
Koi are poikilothermic fish that depend on water temperature to regulate many of their internal bodily functions. As temperatures drop during winter, koi metabolism slows down. This affects their energy stores and their swimming behavior.
If your pond has frozen over, your koi will gravitate towards the bottom part of the water column, where the temperature is considerably warmer. They may often appear to not be moving under the ice. If you observe them for longer periods of time, you’ll see that they make small movements and will swim over short distances. They must remain somewhat mobile so that their joints don’t seize up in the cold.
6) High fish density
An overcrowded fish pond can reinforce many stressful scenarios for your koi. A high fish density is associated with a higher waste load, increasing the demand for oxygen. Keep in mind that your koi will likely breed over time, increasing your fish density even further. Overcrowding can also lead to aggression and competition for food. Less vigorous koi may be deprived of fresh food and subjected to nutrient-poor or bacteria-ridden pond bottom scraps.
Moreover, the frequency of physical contact between fish may increase the chances of fright and disease transmission. Parasites will more quickly be transmitted from one fish to another, leading to an entire pond of sick fish! If that’s a nightmare for a pond owner, you can be sure it will feel even worse for the fish. Try to avoid overstocking your pond to save both yourself and your fish from having to deal with accumulated sources of stress.
7) Old age
Old age can understandably cause koi to grow weak and tired, just as it affects all other living things. As organs begin to deteriorate, the immunity of your koi can grow stagnant or static.
Old fish are no longer able to tolerate and recover from water fluctuations as they once did. When brand new or young koi are introduced to a system, some of the older koi may experience ‘old pond syndrome’. This occurs when their bodies aren’t able to cope with an influx of new bacteria. Koi can supposedly live for dozens of years, but their lifespan is largely dependent on the skills of the pond keeper or on their genetic strain.
How to Respond to Immobile Koi
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Once you’ve spotted a koi that refuses to move and doesn’t readily take food, you must dedicate some time to evaluating your pond situation. Of course, you must first check if the immobile koi is breathing. You may have to gently fish your koi out of your pond if unable to get a good view of its gills. This will also allow you to inspect its capacity for movement, as a strong fish is more likely to swim away from a net. Check if any other fish are behaving similarly or showing signs of stress.
Go through your mental checklist of pond parameters, making sure to test for each one as accurately as possible. If you find abnormal levels of nutrients, pH, water hardness, or chlorine, respond by conducting a water change or by making use of pond additives to bring values back to normal. If your dissolved oxygen has suddenly dropped, consider adding an electrical air pump to your pond.
Do I Need to Quarantine My Sick Koi?
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If all water parameters are normal and your fish still show signs of stress, you will have to consider isolating the affected individuals.
Remove any dead or weak fish and transfer the live ones to a quarantine tank. This will help prevent transmission in case the affected fish have infectious diseases and parasites. For ease of mind, you may opt to consult a veterinarian or a more experienced pond keeper to help you determine the proper mode of treatment. If unable to do so, try to closely examine your koi for parasites. Make sure to inspect the mouth, fins, gills, scales, and tail of the fish for anything that appears out of the ordinary, but do so gently and carefully so that you do not cause injury.
If unable to detect any parasites, you can use a broad-spectrum antibacterial and anti-parasitic medicine made for ornamental fish. Make sure to read the label correctly and avoid simply eyeballing how much to add to your quarantine tank. It can understandably take some time for your fish to recover (if the ailment is reversible), so try to be consistent about maintaining optimal conditions for your sick fish. For good measure, give your quarantined koi additional time to recuperate separately even if they have begun to show signs of normal swimming behavior.
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