Luxilus cornutus

The most obvious distinction between tropical fish and native fish is the temperature of the waters from which they originate. This common shiner (Luxilus cornutus), from Pennsylvania prefers cooler water than most tropical species.

North American Fish Collection Maintenance. In the first half of this article we discussed how to collect and transfport native fish from their natural aquatic environments to your home. We now move on to what todo with the fish when they arrive home and how to maintain them we’ll also take a look at some of the species that you might want to consider for your native fish aquarium.

Acclimating native fish to your home aquarium is much the same as acclimating tropical fish with one important difference. Newly collected native fish may not be tolerant of conditions commonly found in a home aquarium, particularly inadequate dissolved oxygen. As with any fish, the presence of chlorine or chloramine in the water must be avoided. However, with the addition of some type of commercial water conditioner, adequate aeration and perhaps a little salt added to the water, most native fish will have no problem adjusting to reasonable aquarium conditions. Even significant water chesmistry changes such as adapting fish found in acidic waters to alkaline water are usually tolerated quite well (adapting alkaline water fish to acidic water is often a bit more difficult).

Hobbyists who keep tropical fish frequently ask me, “Just what do you feed North American fishes?” Well, what do you feed South American fishes? All fish should receive the best food possible. Some of the tropical fish species found in aquarium stores have survived long, difficult journeys from collection site to store. During that time, any fussy eaters ir fish that couldn’t stand crowding or handling along the way did not survive collector usually don’t ship fishes that are delicate or troublesome. Native fish, on the other hand, are often collected from nearby waters where they are used to high-quality natural foods. Newly caught native fish are at the same stage as Amazon fishes when they are first caught. If they were subjected to the same treatment as their tropical brethren, some native fishes would refuse to eat poor quality food, and would probably not survive. Because native fish are somewhat unpredictable tank residents, it makes sense to give them the very best treatment right from the start, especially food. My rule for feeding native fishes is: always feed the best food you can afford. This usually means high quality live, as well as frozen, foods. For instance, North American minnows will get along fine on dried foods, but it would make sense to give them frozen and live foods as frequent supplements.


Darters, long coveted by european aquarists, belong to a number of genera. The largest genus, Etheostoma, with more than 100 species, includes the biggest and most colorful darters, such as this speckled darter (E. stigmaeum)

Water Quality
The most obvious distinction between tropical fish and native fish is the temperature of the waters from which they originate. How much difference does this make? On the one hand, you definitely will not need a heater for native fishes an unheated basement will do just fine, year round. On the other hand, many tropical fish aquarists especially those who keep fish at room temperature or in a heated fish room think that the lower temperature requirements of native fish add to the difficulty of keeping them. Temperature does make a difference, but it is surprising just how resilient most native fishes are to being kept at room temperature. The most important thing to remember is that native fishes come from cool waters, high in dissolved oxygen content. Because cooler water retains more oxygen, North American fish are going to require more oxygen in their water than most tropical fish. Up to a point, water circulation can substitute for coolness, because the greater the surface agitation, the greater the oxygen content of the water. Moreover, turbulence can help dissipate carbon dioxide, a waste product of respiration (utilized by plants, however). If you cannot maintain water temperatures below 75 degrees Fahrenheit for natives, such as sculpin, which have never experienced temperatures higher than 70 degrees Fahrenheit, increasing the aeration may make it possible to keep them alive and well. If the best you can do is 80 degrees Fahrenheit, however, the fish will have problems, regardless of the amount of aeration you provide. Another way to maintain a higher oxygen level in the tank is to pay close attention to regular maintenance. The mineralization of accumulated wastes and the process of biological filtration use up oxygen.

The more organic material there is in the tank, the higher the utilization of oxygen. Thus, it is advisable to keep the water and substrate as clean as possible with adequate filtration and regular partial water changes.  The surprising adaptability of most natives to room temperatures does not guarantee that health complications will never arise. Some species, for instance, need cold wintering in order to breed successfully. Others, including darters, seem to “color up” more when the water is cool. But temperature is not generally as much of a problem as most tropical fishkeepers tend to think. Remember, a lot of North American fishes experience tropical water temperatures during the summer. The only other significant difference between natives and tropicals is the increasingly important role the seasons play in the breeding of most North American species. An experienced aquarist will have few problems, and for those less experienced, there are books available on the subject. Otherwise, just use common fishkeeping sense.

Erimyzon oblongus

suckers are a type of large minnow, most prefer well-oxygenated, moving water. a creek chubsucker (Erimyzon oblongus) from New Jersey, is pictured here.

Bring In The Fish
So, what about the fish? Many aquarists are surprised at just how many North American species there are some 700 plus. If you include the more exotic species introduced by government agencies and the tropical fish introduced by unwitting aquarists, that number would probably be closer to 800 or more different species of fishes in North American waters.  Native fish often conform exactly to the picture that most aquarists have of them silver to grayish yellow, nondescript fishes. Actually, there are probably just as many “drab” tropical fish, but these are seldom collected for sale in aquarium shops, leaving a somewhat skewed impression that tropical fish are all very colorful and native fish are all very drab. Many native fishkeepers tend to concentrate on those fish that most tropical fish hobbyists consider ‘ugly.’ This is because as one becomes familiar with the habits and behavior of the fish found at a given location, especially over a long period of time, the type of coloration becomes less significant. You begin to appreciate the fish’s specific behavior patterns. In addition, there is increasing respect for how the various species of fish play important roles in their natural habitats. In nature, “beauty” can , be defined as “environmental suitability.” Native fishkeepers share this view and learn to admire and raise superior specimens of “drab” species. It also comes as a surprise to tropical fish hobbyists that many native fish are extravagantly colorful. You may remember hooking a pumpkin seed (common sunfish) as a young angler. Have you ever seen a brighter colored fish? In addition to those native fishes that remain in color most of the time, there are some that color up incredibly as a preliminary to breeding. The North American minnows, for instance, exhibit gaudy shades of red or orange. Many natives are attractively marked in “earth tones.” It’s extremely difficult to resist baby sculpins covered with black, brown and cream blotches. And, fishes like saddleback darters and northern hog suckers do wonders with brown and black and silver and yellow. There are also those fish whose aquarium behavior is fascinating, horrifying or endearing “personality” fish that add life to any tank. What follows, then, is a brief survey of those fishes available in Nort America.

The eastern and central mudminnows (Umbra  Pygmaea and U. limi) are particular favorites of mine. They closely resemble the Rivulus species (neotropical killlies), but are related to the pikes! As with a 3-inch pike, mudminnows will sneak up on their food and then snarf it ! Their swimming resembles a dog paddle rather than a graceful gliding. Moreover, they said droughsts by living in the mud of dried up ponds. They have bred in aquariums, with the female running the show and attacking the males. Trout. Keeping trout in a home aquarium is indeed a challenge. First, you need to be sure that it’s legal. If supermarkets and restaurants can keep them alive, it’s not an impossible task, nor is it always illegal! I haven’t kept trout often, but when I have they’ve been aggressive, particular and given to jumping out of their tanks.

Noturus albater

among the catfishes of North America, madtoms (Noturus albater) prefer dimly lit tanks and may be extremely secretive. This individual is from Missouri.

Minnows. Many people associate the word “minnow” with small fish in general. Actually, it’s the name of a definite family of fishes that includes tropical barbs, as well as native shiners, dace and chubs. They are a diverse, often colorful, lively group, and are the largest family of fishes in North America. Shiners make up the largest group within the family. Most minnows prefer flowing water. Sometimes, the sheer grace of their swimming is justification enough for keeping them such as swallowtail and spotfin shiners and the blacknose dace. Long before tropical fish were widely available in the United States, there were aquarists who kept shiners and other minnows. Minnows are easy to find and collect and not difficult to keep. They do very well in aquariums. Nearly all “pig out” and thrive on dry food, although live and frozen supplements would be advisable.

Suckers are a type of large minnow whose mouth has evolved into a “sucking” device similar to some tropical algae eating catfish, except that a few are aggressive. Most suckers prefer moving water. A well balanced, diverse plant and animal diet is required for long term success. Many adults do not adapt easily to aquarium life and require live, natural foods until they get the hang of things. Few have bright colors, although many have attractive markings.

North American catfishes include a lot of fishes well suited for the aquarium. The madtoms are made for aquarium life, at taining a length of 3 to 6 inches. Although a few of them are attractively marked, bright colors are lacking, as is typical for many tropical catfishes. The only reason many of these small catfish have never been bred in aquariums is that no one has given them a fair try. It would be interesting to do so, because parent catfishes observed in nature guard their fry and offer their mouths as refuge for the young. Madtoms prefer dimly lit tanks and may be extremely secretive. Different species prefer different habitats, from sluggish backwaterss to stiff currents; it’s necessary to study known habitat preferences to have a good chance of catching a desired species. One word of caution about North American catfishes: all of them can sting. They have sting glands at the base of their fin spines or toxic capacity in the skin that sheathes the spines. It hurts, but the pain passes quickly.


the most popular native aquarium killies come from the large North American genus Fundulus, and are bigger than tropical killies. the fish shown here is a plains killie (F. zebrinus zebrinus), from Texas.

There are also North American killifishes. The most popular native aquarium killies come from the large, North American genus Fundulus. These are bigger than most tropical killies. Some are attractive, while others are quite drab. Even though they tend to be more aggressive than tropical killies, they breed like their tropical relatives and, many species include brackish water populations. In fact, most are quite adaptable to varying levels of salinity. There are three popular southeastern “mini” killies: the closely related bluefin and rainwater killifish and the “swamp” Riffle (Lucania goodei, L. parva and Leptolucania ommata). Bluefins are named for the powder blue, unpaired fins of the male. Rain waters, mostly brackish fish admired for their durability, inhabit many brackish Atlantic coastal wa-ters and have been introduced to the Pacific coast. They color up only briefly males display orange and blue fins (rarely pictured). The beautiful yellow swamp or lemon killifish (Leptolucania ommata) inhabits swamps and swampy creeks of the southeastern coastal plains. Often stereotyped as denizens of quiet, heavily vegetated water, a number of killies are quite versatile. In the same creek system, some individuals exhibit the stereotype, but others venture into rapidly flowing water. There is also unexpected versatility among native livebearer species (and subtropical ones). They can usually be found in quiet, alkaline water, but can also turn up in fast flowing water and even acidic water, as well.

Sticklebacks are fun to keep. In some populations, the ubiquitous, mostly brackish water, three spined male assumes stunning spawning colors bright green, turquoise and flame red. They are most famous for their fascinating behavior, such as nest building or their reaction to bright colors. Many species frequent brackish water.

Sunfish.  Sunfish seem to have more personality than other fish. Most males become quite colorful. Although aggressive in tanks, they are no worse than cichlids of the same size. As with cichlids, the adult size range is considerable, from 3/4 inch to a couple of feet, if you include the ‘black basses.” Most will breed in aquariums of the appropriate size. As a rule, sunfish favor quiet waters, but a few, such as the midwest longear and the eastern redbreast, prefer moving water. Perch. The perch family offers some supreme aquarium fish the darters. The breeding colors of many of these bottom dwellers are reminiscent of, and in some species more spectacular than, the colors of African killifish. Nearly all do well in aquariums and most will breed in an aquarium. Most require live, frozen or high quality dead food; only a few take flake food. Most darters like swift, clean water.

Schaphirhynchus platorynchus

when it comes to native species, there are a lots to choose from. pictured here is shovelnose sturgeon (Schaphirhynchus platorynchus)

Sculpins are fascinating bottom dwellers. They have broad heads and frog faces, with bulging eyes and wide mouths the better to eat your prize darters with. Nearly all species prefer fast water. Fast water species require cool water; in fact, returning them to their natal creeks in summer is advisable. Other species, including the southern banded or the northwestern reticulated, can stand less vigorous, warmer water. Sculpins may have trouble adjusting to aquarium food. It is advisable to feed them live foods initially. They can usually be weaned to frozen food later on.

Finally, let’s hear it for the all American oddballs. These are the monsters. There’s the sinister bowfin, reminiscent of Asia’s snakehead. There are the skinnily ominous gars and pikes. Alaska Blackfish giant paisley mudminnows are in a class by themselves. Then there are the parasitic lampreys, begging to be smuggled into a former friend’s prize discus tank. And, these are just a sampling ! So, there you have it, a brief look at the fascinating world of native fishkeeping. European aquarists discovered long ago just how desirable our native species are, while most aquarists in this country are seldom even aware that these fish exist. You can change that.