That Fish Blog – Aquarium Advice and Information

Live foods are popular for larger predatory fish and even some inverts, and some new or finicky animals may not eat anything else. Unfortunately, they aren’t always the most nutritious in an aquarium setting. It is much easier to get a larger variety out of frozen or prepared foods or enhance them with additives, so how can you make the most out of live foods if it is your only option?

Picky fish like seahorses can be tricky to feed

“You are what you eat”…and so are your fish

The problem with feeding most live foods is a lack of variety or nutritional content. Common live feeders like ghost shrimp or guppies just don’t have a lot to them and feeders aren’t usually raised or bred with as much care as animals intended to be ornamental. Much of the most nutritious foods in nature are also some of the smallest – microfauna like copepods and the bright red Cyclops, for example – but these critters are far too small for something like the finicky frogfish or lionfish or sharks that may need live foods and they just aren’t practical to raise.

So, instead of feeding that tiny food to the bigger predators, feed it to the food! This method is known as “gut loading” and is commonly used when feeding crickets to reptiles or amphibians but has a lot of practical use for aquarium hobbyists as well. The principle of gut loading is to feed nutritious food to the live feeder, then feeding that live feeder to its predator while the nutrients are in its system. This is making a process known as bioaccumulation work for us instead of against us like we see in effects like the ciguatera poisoning we discussed in the past.

For example, many planktonic foods are very nutritious but too small for a fish like a frogfish. Frogfish will often hunt down and eat ghost shrimp which are very common (but not especially nutritious) feeder shrimp. So, if we feed the plankton to the ghost shrimp, then feed the ghost shrimp to the frogfish, the frogfish eats the plankton.

Gut Loading:  How to pack it in

Specimen containers make ideal holding areas for gut loading

With a name like “gut loading”, images of stuffing a guppy like a Thanksgiving Day turkey may come to mind but in reality, its much easier. Just feed the live feeder before it becomes food. For smaller feeders like guppies, ghost shrimp, or even crickets or mealworms, it is usually easiest to put the feeder in a smaller separate container from wherever it is being housed. In our store, we will put ghost shrimp in one of the small specimen containers we use in catching your fish. This keeps the system where the rest of the feeders are being kept cleaner and concentrates the nutritious foods you are using for the gut loading to where the feeders are sure to find it. Then, let the feeders feed. For transparent feeders like ghost shrimp, it is easy to see when their guts are full of the food you are using. For others, monitor how much they are eating. Usually anywhere from 15 to 45 minutes is plenty of time; after all, we don’t need the feeder to digest the food, just get it into their guts. Once they’ve eaten their fill, off to become a meal they go!

Cyclops are tiny, nutritious crustaceans perfect for gut loading

Depending on the predator you are trying to feed in the end, you can gut load with zooplankton like Cyclop-eeze, phytoplankton like Spirulina, nutritional supplements like garlic or vitamins or even some medications (best with the fish only and not inverts). The foods you are using for the gut loading can be fresh, frozen, freeze-dried, flakes or in a liquid suspension. Experiment and see what works best for your predators or give them a nutritious snack as a treat!

If you’ve been an aquarium keeper for any significant length of time, you know that unexpected things can appear in your aquarium seemingly overnight. You may not know where they’ve come from, but suddenly you’re faced with overwhelming numbers of “alien” invaders in your tank, creeping, crawling and swimming all over.  Your immediate instinct may be to search for a quick chemical solution to eradicate the unsightly pests, but isn’t it safer for your fish and the aquarium habitat as a whole to solve the problem naturally? We discussed eliminating the causes of some of these critters as natural remedies in other articles, but this time we’ll take another approach…the possibility of finding and adding natural predators to the pest species you’re struggling with. It’s important to keep in mind that though these creatures have been effective in the tanks of other hobbyists, you can never predict the behavior of an individual fish and you may not get the results you’re looking for. Also remember that these fish have to be compatible with the habitat you’ve created and with the other fish in your tank…if you introduce any neew fish or invert to your tank, observe them closely to make sure all of your fish are getting along.

Snails

Whether you have live plants in your tank or not snails can appear in your tank and quickly boom in population. While they have their benefits as algae eaters and detritivores, they can become a nuisance if the numbers aren’t kept in check. Generally, for common snails we recommend botia loaches including Skunk Loaches, Clown Loaches and YoYo Loaches. These fish like to indulge on young snails and snail eggs, so they can get you ahead of the problem. However, they can be pugnacious and even a little aggressive in some cases, so they may not be a good idea in a tank with very small or docile fish.  True Siamese Flying Fox fish are another great solution, if you can find them in the trade.  If you’re plagued with Malaysian Trumpet Snails, your options may be more limited. These snails have much tougher shells than the common little snails that sneak in on live plants, and they can only be ripped out of the shell by specialized eaters with very strong mouthparts.   While the loaches may be able to handle very small Trumpet snails, larger versions will be too tough.  Some cichlids, including several Julidochromis species develop a taste and talent for eating snails, and C. rhodesii is also a known specialized feeder for trumpet snails. Read More »

For as long as this blogger can remember, when it comes to feeding your fish there have only been a few options available to the concerned aquarist. You can try to find those rare-gem high-nutrition flake foods that won’t quickly pollute your tank if add too many. You can spend top dollar for a hard pellet that your fish have to bite and spit out several times only to let it fall to the gravel to be ignored. You may even have frozen cubes of fish food sitting in the door of your freezer right next to the ice cubes and Creamsicles, much to the abhorrence of your significant other.

Fortunately for us fish geeks, a New Era (pun intended) of fish food has dawned upon us. UK based company, New Era, has produced a game changing array of innovative foods. They uniquely manufacture their foods with a slow, low-temperature, and low-pressure process that maintains the nutritional content of the formula, unlike foods that are quickly baked at high temps have many of their natural vitamins and minerals cooked away. New Era’s processing method also leaves a soft, highly chompable pellet that your fish will be able to eat in the first bite. These pellets are soft enough that you can and roll them into a ball in your finger tips or break pieces off for smaller fish.  But don’t let this texture fool you; they won’t melt and or dissolve away instantly in your fish tank. Between the quality of the ingredients, and unique palatability of the food, your fish get more nutrition with less waste, ultimately leading to a cleaner aquarium. Read More »

Overfeeding your aquarium is one of the most common mistakes made by aquarium hobbyists, and it isn’t one only made by beginners. It’s easy to go overboard when our fish “always seem hungry” and even appearing excited when they see you coming towards the tank with food in hand.  Healthy fish pretty much always look hungry. It also doesn’t help that we’re directed by packaging instructions to feed amounts that may be inappropriate for the type and number of fish we are keeping. We want the best for our fish and we want to be successful in keeping them, but it’s easy to cross the line from feeding enough to feeding way too much.

Problems Caused by Overfeeding

Leaving uneaten food in the aquarium is never a good idea. Watching food fall to the bottom of the tank, with the thought that your fish to eat later, can lead to big problems. Many fish are kind of programmed to eat food at certain places in the tank. Surface feeders, column feeders and bottom feeders tend to feed within their comfort zones, so you won’t typically see surface feeders travelling to the gravel for a snack, and fish that feed in the water column usually ignore food bits after they settle. No matter what kind of fish food you distribute, pellets, flakes, frozen foods or even live feeders, anything not eaten is left to decay. This unprocessed food, in addition to the waste produced by the food that is actually digested, can quickly create issues with your tank’s water chemistry and/or cause a bloom in the population of naturally occuring scavengers.

Uneaten foods quickly start to decay, adding to ammonia and nitrate levels of the aquarium, and it can very easily result in more bacteria than the nitrogen cycle can handle causing cloudy water. Overfeeding is not only dangerous to the health of your fish, but it causes unnecessary demands on your filtration, often resulting in poor water quality. Fortunately, the problems that arise from overfeeding are quickly and easily reversed or eliminated once you get your feeding habits under control.

Aquarists are also often shocked or full of disbelief when we tell them that the hordes of unsightly little “bugs” or worms creeping up the glass and through the rock and substrate are a probably a result of over-feeding their aquarium. What you see are probably either scavenger nematodes or planaria. Chances are there were a few of these critters in your tank from the start. They can be introduced via fish, plants, wood or other things you add to the aquarium as their microscopic eggs can travel on any of these things. They are generally harmess, but when you overfeed the opportunity arises for their populations to boom with the abundance of decaying matter in the substrate. Reducing the frequency and amount of food will help to bring the population back down to size, but you may also choose to treat the tank with anti-parasitic medications to speed the process along. Read More »

Many years ago I established a school of 75 Boezeman’s Australian Rainbowfish (Melanotaenia boesemani) at the Bronx Zoo.  The exhibit, which they shared with mangrove snakes, land crabs and crayfishes, made for a stunning display.  And although the building also housed proboscis monkeys, marsh crocodiles, hornbills and other impressive beasts, the brilliantly-colored Rainbowfishes drew a great deal of attention from visitors.

But many keepers become disappointed when, after a time, their fishes’ fading colors do a disservice to the “rainbow” part of their name.  Based on experience with related species, I’ve always provided my Rainbowfishes with highly varied diets, in which insects were heavily featured.  Those under my care have usually retained their bright colors, and breeding has been consistent.  A recent study that examined the natural diet of wild Rainbowfishes seems to bear this out, and has important implications for the care of other species as well.

Uploaded to Wikipedia Commons by Roan Art

Terrestrial Insects: an Overlooked Food Item

My lifelong observations of captive and free-living fishes have led me to conclude that land-dwelling insects play an important role in the diets of many freshwater fishes.  As anyone with a pool or outdoor pond can imagine, untold numbers find their way into fresh and marine waters each day.  In 2009, the research of National Oceanographic and Atmospheric Administration biologists revealed that terrestrial insects comprise up to 100% of the diets of some US fish species. You can read more about this topic in the articles linked below. Read More »