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Overfeeding and Water Quality

Please welcome Sam Yost as a blogger on That Fish Blog.  Sam has recently been promoted to Fish Room Supervisor and will be graduating from Millersville University in December with a degree in Marine Biology. 

Hello, My name is Sam Yost.  Being a hobbyist and working with other hobbyists in the trade, I have grown to understand that  keeping good water quality is one of the most important parts of aquarium keeping. If your aquarium water quality is bad, and a regular maintenance schedule is not kept, your fish will not be healthy, or will not live to their full potential.

There are many things that can happen in a tank to degrade the water quality. One of the major problems in maintaining water quality is overfeeding.  By overfeeding, a lot of unused food ends up breaking down in the tank.  It can be difficult to tell when fish have had enough, especially if there are a lot of fish in the tank, but it may be best to underfeed instead of dumping copious amounts of food. When uneaten food breaks down in the tank, it can cause a spike in ammonia, nitrites or nitrates. This spike, even if it is small, can be deadly to fish.  It may also settle into the substrate, where it can break down and cause chemistry problems, fish illness and other problems down the line.

There are several things you can do to help alleviate these overfeeding/water quality issues.

Consider what your fish need. Different fish can require different types and sizes of food, and some may require more frequent feedings than others. Generally, fish should be fed food that is about the size of their eye or smaller, or foods that can be broken easily, like flakes, that they can easily take in.

The amount of food administered should be what they can consume with in a minute or so. It is better to feed your fish several small meals than one large meal. Generally in a community, small feedings in the morning, evening and night will work great!  By doing three small feedings, there is a smaller amount of food being wasted.

Small, frequent feedings are also more healthy for the fish.  They are not eating so much that they look bloated, and the food can be used more efficiently.

You can also minimize the amount of waste that is put in to the tank by rinsing frozen food. This action gets rid of excess preservatives that are used to keep the food fresh so they go down the drain instead of breaking down in the tank.

Finally, small frequent water changes to reduce nitrates and gravel siphoning after several days can remove any waste and decaying food from the substrate.  A good, regular maintenance schedule will allow you to keep the water pristine and give your fish the best possible water quality for long, happy, healthy lives!



Freshwater Sharks – Striking Species for the Semi-aggressive Community

Hey Fish Blog Followers! There are lots of different types of freshwater communities created by hobbyists. Some people choose a peaceful community of tetras and other small docile fish, while others opt for a tank populated with predators or other territorial species, often a fine balance between tolerance and aggression. Many aquariums are somewhere in between, referred to as semi-aggressive communities, which often include fish such as barbs, gouramis, large tetras and others that fit into the category.  Today I wanted to give a small introduction to several popular species of fish often purchased for these aquariums that may interest you.

Not Exactly Maneaters

Some of the most popular fish for the freshwater semi-aggressive community are the cyprinids known as sharks. These are not the cartilaginous carnivores as featured in movies or the Discovery Channel. These fish are found primarily in the waters of Southeast Asia and Thailand. There are several species that are often imported for use in the aquarium trade, and several species also referred to as sharks that are less common in the trade. Though from several different genera, these fish all have in common the pointed heads and large, curved dorsal fins that give them their misleading common names.

Though these fish lack teeth, as a general rule they are considered semi-aggressive, if not for the sizes they attain, then for the Redtail Sharkterritoriality they often express as they mature. They are generally not suitable for tanks under 55 gallons (some not less than a 75 to 100 gallon tank) and should only be mixed with fish that can stand up to the potential for chasing and harassment that sharks can dish out (especially to their own kind). Smaller fish may eventually be seen as a snack as the fish grow. Sharks make bold and interesting additions to freshwater semi-aggressive communities, as long as the tank is of adequate size and the conditions in the tank suit their needs. Suitable tank mates for most include fish like barbs, catfish, large tetras, and other fish of similar temperament.

If you are considering the addition of a shark to your community, there are several things to keep in mind. As far as the set-up goes (besides having an adequately sized aquarium) be sure that you provide plenty of cover like wood, plants or rock formations so these fish can hide and fell secure when they feel the need. A tightly fitting lid is also highly recommended as they tend to be terrific jumpers, especially if startled. Most common sharks prefer well-aerated, clean water with temps between 74 and 81 degrees (F) and a pH maintained between 6.5 and 7.5. Sharks do not tend to be finicky eaters, readily accepting flakes, pellets and frozen, freeze-dried or live treats like bloodworms, tubiflex, glass worms, plankton, brine shrimp or other meaty tidbits.

Popular Species

There are several species of freshwater shark, and variants of these species, regularly available on the market that may be candidates for your semi-aggressive community.

Bala Sharks (Balantiocheilus melanopterus), also called Tricolor Sharks, are a popular variety with silvery scales and bold black edges on the fins and tail. Though attractive,Bala Shark this species tends to be rather skittish unless kept in small groups. These fish tend to be more shy and docile than many of the other sharks. Reaching a length of between 13 and 15 inches potentially, this species is best left to aquarists with tanks of at least 75 gallons or more for a single specimen, much larger if they are to be kept in the security of a small group.

Rainbow Sharks (Epalzeorhynchos frenatus) may be the best choice for most hobbyists, despite their tendency to become territorial and increasingly aggressive as they mature. Also known as the Ruby Shark or the Red-Finned Shark, this species grows to only about 6 inches and bears bright red fins that are quite attractive. Several variants have also been selectively bred to make things even more interesting, such as albinos and white-finned. These sharks should be kept as a single specimen in the community as they do not tend to tolerate others of their kind in the confines of an aquarium. Red-tail Sharks (Labeo bicolor) are similar in size and behavior to Rainbow Sharks, but lack the red fins and display a velvety black body and a red tail.

Other types of freshwater sharks include Black Sharks, Iridescent Sharks, Colombian Sharks, and others that are even more uncommonly seen in the trade. For various reasons, these species are typically not suitable for the average semi-aggressive community, and careful consideration should be taken before purchasing these species.

Black Sharks are attractive, but they grow rather quickly to about 30 inches in length, too large for most home aquariums. Iridescent Sharks are actually a type of catfish that also quickly grows from a 2 inch juvenile to lengths nearing 4 feet, another that should not be considered for the average home aquarium. Colombian Sharks are sleek and active catfish too, rounding out at about 10 inches, with huge appetites and a preference for brackish to marine conditions as they mature.

Thanks, hope this information is helpful!


Popular Marine Aquarium Fishes – Damselfishes and Clownfishes – Part 1

Hello, Frank Indiviglio here. Damselfishes and Clownfishes are closely related, with all 325+ species being classified in the Family Pomacentridae. Among the most numerous and conspicuous fish on tropical coral reefs, a number make hardy marine aquarium inhabitants.

Range and Habitat

Damselfishes and Clownfishes are found throughout the world’s tropical and semitropical seas, with the greatest diversity occurring in the Indo-Pacific Region, especially off Australia; relativelyBicinctus Clown few occur in the Atlantic and Eastern Pacific Oceans. They occupy a startling variety of habitats, with many species restricted to specific depths or specific areas of wave action. Several species can even enter brackish waters.

Identification in both the wild and pet trade is sometimes difficult, as their colors often vary from individual to individual; different populations of the same species may also exhibit unique color patterns.

Clownfishes and Sea Anemones

Clownfishes (aka anemonefishes) are well-known for their habit of living in close association with an invertebrate that is also an aquarium favorite, the sea anemone. Usually home to just one pair of clown fish, the host anemone forms the basis of their territory, and they rarely stray far from it.

Surviving Among Deadly Tentacles

Clownfishes were long thought to be immune to the anemone’s stinging tentacles, as they shelter right among them without being harmed (other small fishes would be killed if they attempted to do this). We now know, however, that the clownfish’s secret is not immunity at all, but an even more amazing adaptation.

 Amphiprion sandaracinos Anemone tentacles fire their sting-bearing cells (nematocysts) upon contact with any organism that they come in contact with. The tentacles are coated with mucus which inhibits them from stinging one another. It seems that the clownfish secretes mucus which mimics that covering the tentacles of the anemone. Therefore, the anemone simply does not recognize the clownfish as prey, or even as a distinct organism!

In return for the protection offered by its host, the clownfish consumes parasites that might harm the anemone. By swimming about and fanning its fins, the clownfish may also increase the flow of oxygenated water through the anemone’s tentacles and about its base.

Do Anemones and Clownfishes “Need” One Another?

Aquarists often question whether clownfishes and anemones can survive without one other. It appears that the relationship might the best be described as “commensal”. By this we mean that each derives benefits from living in close association with the other, but they are not strictly limited to that situation.

The vast majority of anemones live without clownfishes. Clownfishes, however, seem somewhat more dependent upon the relationship. While they will live quite well “on their own” in the aquarium, experiments in the wild have shown that clownfishes without anemone hosts are quickly eaten by larger fishes.

Further Reading

The Florida Museum of Natural History has posted an interesting article and video on clownfishes here.

Next time we’ll take a closer look at the damselfishes and a favorite aquarium clownfish.

Please write in with your questions and comments.

Thanks, until next time,

Frank Indiviglio

Amphiprion sandaracinos image referenced from wikipedia and originally posted by Bricktop

Fish Intelligence – Research and Products for Home Experiments – Part 2

Hello, Frank Indiviglio here. Fishes outnumber all other vertebrates combined, with nearly 30,000 species identified so far.  No doubt, the ability to learn has assisted in this success.  In Part I of this article, I recounted my experiences with “educated” electric eels in Venezuela, and gave some other examples of fish intelligence.  I’ll continue here, with an emphasis on memory.

If you would like to experiment with your own pets’ learning abilities, please check out our extensive line of fish feeding products , and don’t forget to write in with your observations.

Memorizing Terrain

Frillfin gobies inhabit tidal pools.  When disturbed, a goby will leap from its pool to several others in succession.  It always lands in another pool, despite the fact that it is jumping without seeing the next pool, and changing directions.

Ichthyologists (fish biologists) have discovered that gobies memorize the location of tide pools at high tide, when they swim about over the area in which they live.  Imagine, if you will, trying to do this yourself while snorkeling…and then consider the how much more complicated the task would be to a tiny fish!

Gobies transplanted to unfamiliar tide pools refuse to jump…if forced to do so, they invariably miss the next pool and hit dry land.  Yet after just one high tide, the gobies learn the new habitat and can then jump accurately from pool to pool.  In what must surely be the most amazing fish memory feat known, the tiny fishes retain their internal map of the new tide pools even if removed from the area for 40 days!

Learning by Observing Others

Sea bass were allowed to watch other bass undergo a training program in which the participants were rewarded with food if they pushed at a certain lever.  Some bass were better than others at learning this skill.  “Student bass” that had watched “smart” bass immediately pressed the levers themselves when given the opportunity.  Those that had observed bass that did poorly in the training took much longer to master the lever trick themselves.

French grunts travel from sleeping to foraging grounds each day. Grunts re-located to new habitats follow resident fishes to and from foraging grounds.  After 2 days, the transplanted fishes are able to find their way to the foraging grounds – an average distance of .5 miles – even if the resident grunts are removed.

Goldfishes that watch others foraging in an aquarium with hidden food are able to learn and remember what areas of the tank held food. When released into the tank, they ignore areas where the original fishes found no food, and head immediately for the most productive feeding sites.

Remembering Bad and Good Experiences

An American eel that was my mother’s (somewhat unusual!) pet for 17 years quickly learned to associate people with food.  It was kept in a high-traffic area, but did not rise to the surface for food unless someone stopped in front of its aquarium…people passing by were ignored.

Perch separated from minnows by a glass partition stop trying to catch the minnows after crashing into the glass.  When the glass is removed, the perch refuse to chase the minnows, apparently associating them with a bad experience.  Note: this lesson wears off when predators get very hungry, so don’t try it in hopes of keeping Oscars with sword tails!

Further Reading

You can read more about fish learning abilities in an interesting Fish and Fisheries article and in The Everything Aquarium Book.

Please write in with your questions and comments.  Thanks, until next time, Frank Indiviglio.

American Eel image referenced from Wikipedia and originally posted by Freida.

Fish Intelligence – Research and Products for Home Experiments – Part 1

Hello, Frank Indiviglio here. The natural behavior of fishes is so interesting that one can easily overlook the fact that they are capable learning in the true sense of the word (i.e. changing behavior in response to experience). Fishes are, after all, the most successful vertebrates in terms of species diversity (nearly 30,000 species have been described so far) – it would be odd indeed if they did not possess some capacity to profit from their experiences.

What All Fishes Learn

Some evidence of fish learning ability is so common that we usually do not appreciate it as such. From guppies to giant pacus, aquarium fishes of all types gather in anticipation of a meal when they see their owner approaching, or if the aquarium light is turned on. Seems simple to us, but these “simple” creatures are associating a large being (us) with food, something that instinct would never cause them to do.

Observations in the Field: Electric Eels

As you can imagine, forming associations similar to “people=food” can increase hunting success in the wild.

Years ago I was involved in fish and anaconda research on a cattle ranch in Venezuela. The ranch owners periodically replenished their stock’s water supply by lifting a gate that separated the cattle-watering channels from a river. As soon as river water began splashing into the channels, the huge electric eels (which are actually knife fishes) that lived in the channels would appear at the gate. They had obviously learned that fishes and other prey were carried from the river to the channel with the flowing water.

Some of these brutes approached 6 feet in length. When grabbed in the mistaken believe that it was an anaconda, one large eel knocked a co-worker off his feet with its electrical discharge.

Home Training Devices

If you would like to experiment with training your own fishes, please check out our extensive line of fish-feeding products. Automatic fish feeders, feeding stations, feeding clips and feeding tongs can be used to duplicate some of experiments described below. Of course, the possibilities are limitless, so please write in with your own ideas.

Following are some other brief examples of piscivorous learning abilities:

Feeding Associations

Archerfish (which feed by shooting jets of water at terrestrial insects) that were fed immediately after a light bulb went on soon squirted water at the bulb, in anticipation of a meal. I find this particularly interesting because archers generally shoot only at moving objects.

I recall that archers under my care shot water at their exhibit door as I opened it – I thought they were reacting to the movement, but perhaps they associated the opening door with food.

Territorial Defense

Male bettas that were shown a rival male directly after a light bulb came on soon began displaying to the bulb, without seeing another fish.

Male sticklebacks perform an elaborate display when confronted by competitors. Researchers hid the competitors from view each time the males exhibited the “head down” portion of the display…in effect convincing the displaying fish that the interloper had fled. Realizing that this part of the display was very effective, the males soon began performing it earlier and more often than usual.

Next time I’ll relate more experiments that give evidence of fishes’ surprising learning abilities. Until then, please write in with your questions and comments. Thanks, Frank Indiviglio.

Further Reading

You can learn more about fish intelligence in the following article:
http://www.thefishsite.com/fishnews/10129/fish-found-to-have-human-learning-abilities and in The Everything Aquarium Book, which I wrote several years ago.

Electric eel image referenced from Wikipedia and originally posted by StevenJ.

Archerfish image referenced from Wikipedia and originally posted by Okapi.