Tropical Fish in the Snow

Now that winter is back again, we once more have the opportunity to see one of the world’s truly unique vistas…tropical fish in a snow bound lake. Yes, just 1½ hours from Calgary is the only place in the world that tropical aquarium fish live outside, wild, all year long, in a natural body of water that has snow around it. It is the marsh below the famous “Cave and Basin”, in Banff National Park, just west of the Banff townsite.

The Cave and Basin is an historic site and one of the major tourist attractions in Banff. The site was first brought to public attention in 1883 by William and Tom McCardell, and Frank McCabe; three railroad workers who followed a free-flowing stream (that was still warm to the touch in the middle of winter) up to its source: a collection of hot (well, warm) springs on the north side of Sulphur Mountain. One of these springs was in a small but lovely cave set in the cliff face. Two other springs were open to the sky. The men wanted to take ownership of the site and build a bathhouse/resort there. However, the federal government saw fit to intervene and used the feature as a cornerstone attraction for our first national park, which was incorporated in 1885.

The springs immediately became a popular swimming area. Warm, but not nearly as hot as the springs on the mountain’s eastern flanks, the Cave and Basin springs were a popular place of recreation. The warmest spring (in the cave) was a famous “medicinal” spring. The coolest spring, with a temperature of about 27C, could be used for a refreshing swim on a hot day, without being brain-numbingly cold like the typical mountain lake is in even the hottest summer.

A resort was built on the site in 1886, to be later expanded in 1932. But, although the resort was commercially successful, even the hardest nosed capitalist would be hard pressed to call this development an improvement in any sense of the word. It must be remembered however that the primary purpose of the national parks at that time was recreation, not conservation. Banff was (as the park’s historians like to say) an island of civilization in a sea of wilderness, and development – any development – was welcome. But nowadays the park is an island of wilderness in a sea of civilization, and development threatens the very thing that the tourists come to see. And in the case of the Cave and Basin, all natural beauty is long gone. The Cave is now just a room in the resort building and even the exterior springs are surrounded by walls. Sigh.

The desecration of these natural wonders was more than just an aesthetic loss, as unnoticed in the springs lived a small, rather non-descript, pond snail. The Banff Springs snail (Physella johnsoni) was originally endemic to five springs and their outflow streams near Sulphur Mountain. It was known to occur in the Upper Hot Springs, Kidney Spring, Middle Springs, the Cave and Basin, Vermilion Lakes Spring, and a warm stream near the Banff Springs Hotel. Now they are found only in one of the Cave and Basin springs, its outflow stream, and the Cave and Basin marsh below the spring. The reason for its disappearance in the other locations is believed to be development and human disturbance of the algal mats upon which the snail feeds. Now all swimming in the Cave and Basin is forbidden in order to preserve the species, and so the resort has lost its original reason for existence. Today it is a museum and interpretive center.

Compared to the springs themselves, the stream and marsh below the Cave and Basin are relatively pristine “warm water” ecosystems. However, human interference has been at work here too, as residents of Banff released a variety of tropical fish into the marsh after the war years (no one seems to know exactly when this happened). At one time or another, angelfish, guppies, and tetras have all been spotted in the marsh, but these failed to thrive and are probably no longer present. Now there are three introduced tropical fish species known to live in the marsh; Gambusia affinis (the mosquitofish), Poecilia latipinna (the sailfin mollie), and Hemichromis bimaculatus (the jewel cichlid).

Getting to the see these fish is easy – the route to the Cave and Basin is well signed. Follow the main drag through the town of Banff west until you cross the Bow River, then turn right. Head down the road another mile. From the Cave and Basin parking lot, walk up to the main building and around to the north side. Take the “Discovery Trail” north of the main building (there is no reason to actually enter the building). A boardwalk goes down to the marsh, culminating in a “fish-watching” platform.

Along the way take note of the white algae growing in the springs’ outlet stream. I found this stuff fascinating (how does it photosynthesize without pigment?) but could not find out anything about its biology.

Be careful heading down the boardwalk as it can be icy in winter. On really cold days fog shrouds the marsh, making the scene very otherworldly, but although beautiful, the fog doesn’t help you find any fish. The best place to see the fish is (not surprisingly) the fish-watching platform. Lie quietly on the platform with your head over the side, and in a few moments the fish will reappear. Pretty much all of the fish you see will be introduced tropicals.

Personally, I found the mollies a bit of a disappointment. They are much smaller than well-fed aquarium specimens. And although all were originally black, they have over the generations reverted to their original spotted coloration. So from the top (looking down on their backs) they aren’t too impressive. I saw one male however with a lovely sail fin and a pleasant yellow cast to its fins. Quite nice. The jewel cichlids are also small (about 6cm) but feisty and in nice color. And the male mosquito fish court like male mosquito fish do.

Although the tropical fish are introduced, they now enjoy the full protection of the national park authority. You can not legally catch, keep, feed, or unduly disturb them.

It is hard for a tropical fish enthusiast to not to be impressed by seeing these fish in the snow, but it must be remembered that they are introduced species that had a profound impact on the native fishes of the marsh. The marsh was once the only home of the Banff longnose dace (Rhinichthys cataractae smithi), which was declared extinct in 1986. It is highly likely that it was competition with the introduced species that led to its extinction.

So enjoy a walk through the marsh on a winter’s day. But give a thought to what we have lost to greed and ignorance.



Nelson, J.S. 1983b. The tropical fish fauna in Cave and Basin Hotsprings drainage, Banff National Park. Can. Field-Nat. 97(3): 255-261 ?

What’s New In Cichlid Studies: Part 4


One of the basic stumbling blocks facing aquarists trying to spawn their cichlids is the difficulty in getting a breeding pair. Trying to identify which is the male and which is the female is not always easy. Some species are dimorphic, with obvious males and females, usually due to coloration or shape. Others lead aquarists into frustration trying to determine if they have a pair or if they are just wasting fish food on two of the same gender.

Recent evidence is suggesting that it is not always the aquarist’s fault in not being able to identify gender in cichlids. Some cichlid species are known to be able to change gender as a result of environmental conditions around them. The Midas cichlid Cichlasoma citrinellum, for example, develops as a female by default but changes into a male during juvenile development based on its relative size to other juveniles in the brood [1]. Males are larger in this species.

This justifies the traditional advice that if you can’t buy a known breeding pair of cichlids, then get a half dozen young and let them sort themselves out as they grow up. This advice was actually based on probability odds, as out of six fish there is a very strong chance that at least one pair exists. Now one can see the other reason, for if gender can be altered during maturation, then at least one cichlid might switch to a male if all of them are default females to begin with.

Another study using Crenicara punctulata verified this, where it was confirmed that the dominant female in a batch of juveniles will become a male [2]. A female in isolation will turn into a male.

The tilapia Oreochromis mossambicus has its gender determined during its first ten days of life [7]. If during that time, the larvae are in cool water (20o to 24oC), most of them will develop as females. In warmer water (28C to 32C) they will be mostly males.

As anyone knows who reads the aquarium literature, there is all manner of conflicting advice and non-reproducible experiments in the hobby. It can be seen that part of the confusion on how to select and maintain breeding pairs comes about because the aquarist writing the article may not be aware that one or more of the fish has changed gender. It’s enough to make one take up stamp collecting instead.


As stocks of wild-caught cichlids dwindle from habitat extinction, it becomes more important to maintain breeding stocks in captive populations. One problem is the loss of genetic diversity in captive stocks, and the accumulation of defective or sickly individuals. This is often blamed unfairly on inbreeding, but aquarists should realize that inbreeding is neutral. The reason that it gets blamed is because those doing the inbreeding fail to cull out the inadequate fry. Lethal or sub- lethal traits then accumulate, and the problem is then unjustifiably said to be ‘inbred fish’. All breeds of domesticated animals, whether they be Charolais cattle, German shepherds, or roller canaries, were initially established by inbreeding for desired traits. Unfortunately, too many fish breeders can sell whatever they produce no matter what garbage the fish are, which is why you see parrot cichlids and crick-back goldfish in pet stores. But it is not the fault of inbreeding per se, just the failure to select and cull.

Decline in genetic diversity is a more serious problem. It should be understood that low genetic diversity does not mean subnormal quality. Animals in a low-diversity population can be quite healthy and vigorous. However, when the environment changes, or a new disease sweeps through, high genetic diversity allows the species to survive no matter how great the mortality rate. Random variability of the genes ensures that at least a few of the individuals happened to have resistance.

In the aquarium hobby, it is therefore important to maintain high genetic diversity within a species population. The average aquarist cannot maintain large stocks of a species, though. This eliminates the idea of keeping genetic diversity high by the brute-force method of having thousand of cross-breeding individuals. Zoos get around this problem by regularly exchanging individual animals between themselves to keep the genes flowing between sub-populations.

A recent study on haplochromines out of Lake Victoria, carried out at the Ohio State University, showed that the best procedure to keep a cichlid population diverse is to periodically remove dominant males and to maintain more sub-populations [6]. Removing a dominant male after he has bred a few times will allow another male to get a chance to spread his genes about. Sub-populations are subject to random mutation of genes, which then have a better chance of establishing instead of being swamped in one large population.

Genetic diversity doesn’t just mean color patterns or shape. It also means resistance to disease or environmental shock. Behaviour is known to be an inheritable trait. There are many other traits invisible to the aquarist but which have a very real impact on the population.


The reputation of cichlids for nasty behavior is more the aquarist’s fault than the fish. In the wild, the loser of a fight flees the scene and there are seldom fights to the death. In the aquarium, the loser can’t get away, which frustrates the winner and escalates what would have been a brief skirmish into deadly combat.

How do winners know they have won? Obviously, the loser backs off, but another reason is color change. Losers often change color and pattern to submissive or at least aggression- inhibiting colors. An example recently studied is the oscar Astronotus ocellatus, where the loser goes to near black body color with irregular white bars [3]. This sends a signal to the victor, and cools him down.

Victors of a fight have no reason to continue it out of spite, for injuries and wasted metabolism of food energy can be costly to them, albeit not as much as to the loser [4]. The winner of a fight must expend energy that could be used for other things such as spawning or building up food reserves. If a winner continues to beat up a fish in a tank, it is because it is not perceiving that it has actually won the contest. Depending on the species, it may expect submissive coloring from the loser or for the loser to leave the scene. Aquarists who have trouble with murder and mayhem in the tank should bear this in mind, and look to remedies such as netting out the loser. Don’t make life hell for both of them by leaving them jammed in together in a glass box that is obviously too small for them.


Cichlids are the most speciose group of fish, particularly in eastern Africa. There has long been controversy as to why this would be so. The countless color patterns of Rift cichlids have been the obvious point of departure for enquiry, but experimental results have been confusing and contradictory. Wallace Dominey published an hypothesis in 1984 that speciation was driven by sexual selection, which is to say that females prefer bright colorful males of a certain pattern.

While this is believed to be true in general, there have been exceptions. A new study by a group of Dutch ichthyologists at the University of Leiden [5] suggests that the problem in understanding cichlid colors is that each species has two sets of colors and patterns evolving under different pressures. Nuptial or breeding colors are based on sexual selection, where the prettiest male gets the females. Vertical bars, however, are camouflage for structurally complex habitats such as rock piles. Horizontal stripes are associated with piscivorous feeding and/or shoaling behavior. Sexual selection has no effect on bars or stripes. This would therefore explain why previous studies have been at odds with each other, because they thought all three sets of patterns and colors were one.


1] Francis, R.C., and G.W. Barlow (1993) Social control of primary sex differentiation in the Midas cichlid. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES USA 90:10673-10675

2] Carruth, L.L. (2000) Freshwater cichlid Crenicara punctulata is a protogynous sequential hermaphrodite. COPEIA 100:71-82

3] Beeching, S.C. (1995) Colour pattern and inhibition of aggression in the cichlid fish Astronotus ocellatus. JOURNAL OF FISH BIOLOGY 47:50-58

4] Neat, F.C., A.C. Taylor, and F.C. Huntingford (1998) Proximate costs of fighting in male cichlid fish: the role of injuries and energy metabolism. ANIMAL BEHAVIOUR 55:875-882

5] Seehausen, O., P.J. Mayhew, and J.J.M. Van Alphen (1999) Evolution of color patterns in East African cichlid fish. JOURNAL OF EVOLUTIONARY BIOLOGY 12:514- 534

6] Fiumera, A.C., P.G. Parker, and P.A. Fuerst (2000) Effective population size and maintenance of genetic diversity in captive-bred populations of a Lake Victoria cichlid. CONSERVATION BIOLOGY 14:886-892

7] Wang, L.H., and C.L. Tsai (2000) Effects of temperature on the deformity and sex differentiation of tilapia, Oreochromis mossambicus. JOURNAL OF EXPERIMENTAL ZOOLOGY 286:534-537 ?

Adult Fish and Store-Bought Prepared Foods

Fish need food. Otherwise they starve. Simple enough. But like you and me, fish also require that a necessary list of nutrients be in their food or they will slowly grow ill, and then will die. So how do you give your fish adequate nutrition?

Well, thankfully, it is not hard. We have so many very high quality flake foods and freeze-dried foods that fish can be adequately nourished with very little fuss and bother. You may read articles where it is stated categorically that flake foods do not make an adequate diet for any fish, but this assertion has long been disproved by the hordes of aquarists that feed flake foods exclusively, and still maintain colorful, breeding, vibrant fishes. So why not end this article here? Well, it’s not that simple. Just because most aquarium fish will thrive on a good flake food, that doesn’t mean they all will and it certainly doesn’t mean that all flake foods are good. And of course, flake food is boring. Boring for you to feed, and probably boring for the fish to eat. Boring. This is a hobby right? It’s supposed to be fun, right? Well why not get some fun out of meal times then? So I’ll talk about live and homemade foods too.


But first of all, the flake foods. Aquarian®, Tetra®, and Wardley® are all recommended brands. There are some other brands that are pretty good but these three are the most widely available. As a general rule of thumb, if a flake food is for sale in a reputable pet store, it will be pretty good. If you buy it at Walmart® however, you are taking your chances. Department store flake foods tend to have a small list of inexpensive ingredients and a lot of white wheat flour filler. One particularly bad brand that you should avoid has a red label and a name that starts with H and is a homonym for your primary circularity organ (hopefully that’s sufficiently obscure that they won’t sue us for defamation).

Wardley is the least expensive of the recommended brands and is also available in bulk, but the Wardley brand name lacks the range of “specialty flakes” that Aquarian and Tetra offer. As far as these specialty flakes go, the only one I have any use for are the “green” flakes that are high in vegetable matter. Most of these vegetable flakes contain Spirulina, which is a photosynthetic cyanobacterium (so Spirulina is not an alga as is generally assumed). Spirulina is quite high in protein and a great source of many amino acids that are otherwise difficult to acquire. Health food stores are full of the stuff. Spirulina flakes are just what you need for mollies and a host of other vegetarian fishes. Aquarian and Tetra also offer Spirulina enriched wafers that sink, which are very good for algae-eating bottom feeders like plecos.

The various other flake foods, like “carnivore flakes”, “color flakes”, etc. are in my humble opinion more useful as marketing strategies than as dietary supplements. Feel free to purchase a variety of flakes, but all good flake foods are heterogeneous mixtures of ingredients and supply complete nutrition on their own.


Aquarium stores also sell freeze-dried foods. These differ from flake foods in that they usually have only a single animal-ingredient each (e.g. mosquito larvae, blood worms, tubifex worms etc.) and they are usually in the form of chunks or as individual organisms, rather than flakes. These foods are not in themselves complete diets, but they can be part a well-rounded diet consisting of a good basic flake food, a Spirulina-enriched flake food, and several types of freeze-dried foods.

Almost all of the organisms that are freeze-dried and sold for aquarium use can be found as either living or frozen foods as will be discussed below, but in the freeze-dried form they provide a convenience of storing and feeding that frozen or living foods can not match. Feel free to purchase freeze-dried foods if you are unwilling to devote freezer space to frozen foods or to go through the significant bother of dealing with live foods.


The next thing to know about dried foods is how much to feed. Unless you want your fish to spawn or are raising their babies, don’t feed much at all. Fish are cold blooded, and therefore do not require food energy to maintain their body temperatures. They also are neutrally buoyant and so they don’t require any energy to stand up. As a result, fish can get by on remarkably little food.

The rule of thumb to feed all the fish can eat in five minutes twice a day is a good one, provided that all of the fish are actually getting some of the food. This isn’t a problem with schooling fish, but a territorial fish like a cichlid can monopolize a food supply. Most aquarists therefore end up feeding a cichlid aquarium more than the recommended amount, and so they must deal with the high nitrate levels, algae growth, and unwanted breeding that comes with overfed fish. This is just part of the deal when you raise cichlids. But schooling fish can be fed quite sparingly because they will feed as a school rather than competitively. The concentration of their wastes can therefore be kept to a minimum, thus giving you a healthy, easily maintained, and more enjoyable tank.

Then there are the bottom feeders, like loaches and catfishes. What about them? If you feed according to the recommended five-minute rule, your bottom feeders won’t get much to eat. Starvation is consequently one major cause of failure with catfishes, and over feeding in attempt to “make sure the catfish gets some” is another. In practice, however, things are not that bad and catfish can generally find enough to eat (remember fish need very little food). If you have a lot of catfish however, you should take advantage of the fact that most bottom dwellers are nocturnal and supply some sinking wafers when the lights go out. Make sure that this food is gone by morning. By feeding extra at night you are however walking a fine line between adequately feeding your fish and over feeding your fish. So be careful.


As I mentioned before, you may eventually get bored of feeding your fish just flakes. Or the financial realities of purchasing flake foods (yes, you do pay for their convenience) may make you look for less expensive alternatives.

A less expensive alternative to flake food is homemade food. If you like to cook, this can also be fun, although to be honest I tend to think of making your own fish food as a bit of a smelly chore. Thankfully, it is easy to make and freeze enough to last you a good six months or more so you don’t need to put yourself through it very often.

Before your start, get yourself a food processor. Then you can make any one of the various recipes that are kicking around. Most of these recipes have several things in common; namely they are bound together by unflavored gelatin and contain whole fish, vegetable matter, and beef heart. This is my recipe. I food-process several multivitamin tables (with vitamin C) to dust, then process about ½ kilo of the red meat portion of a beef heart (cut away from all the fat and connective tissue). Then goes in a good handful of spinach leaves (no stems), one young whole zucchini, and a few raw carrots. Then the bulk of the food is added, which is whole fish. The fish I originally used were those minnows sold as bait, but I have since discovered Shun Fat, an Oriental supermarket in Forest Lawn (at 3215 17th Ave, SE). Here you can get a wide assortment of frozen sea foods. Nowadays I buy a kilo of frozen capelin since they are full of nutritious roe. I also get a frozen ½ kilo bag of something called “shrimp fry”. I am not sure exactly what this is (some form of krill I think) but it’s a lot cheaper than buying real shrimp, which I would have to do if this wonderful stuff weren’t available. I also add ½ kilo of mosquito larvae and Daphnia that I had collected myself and froze previously (see below for a discussion on live food collecting). All the ingredients are processed to a thick paste. Then a liter of water is added and the mixture is brought to a low boil to congeal the blood. I then dissolve three large boxes (36 packets) of Knox unflavored gelatin in a liter of cool water. I mix this liquid into the food (after it’s cooled a bit) and let the mixture set overnight in the refrigerator. The next day I split the jelly into two or three-day feeding portions and freeze them separately in sandwich-sized freezer bags. I keep one freezer bag defrosted in the refrigerator at all times. My cichlids and turtles love this stuff. It sinks and doesn’t cloud the water (too much).


Many fish either require vegetable diets or can benefit from them. Most notable for requiring vegetables are the plecos (South American algae eating catfishes), silver dollars (vegetarian relatives of the piranha), and mbuna (rock-dwelling cichlids from Lake Malawi, Africa). These fishes have extraordinarily long guts and will develop lower-digestive problems if they do not get enough roughage in their diets. These problems are usually followed by a lethal bacterial infection. Almost all other fish will also benefit from some vegetable matter as greens contain folic acid and the carotenes that are needed for the creation of red and yellow pigments. The vegetables in the gelatin food discussed above are adequate for almost all fish, but plecos and mbuna should really have some additional plant foods as well. Easiest to provide are slices of par-boiled young zucchini (par-boiling makes it sink). Romaine lettuce is also useful. Plecos also eat wood. I’m serious. All plecos should be provided with a nice piece of driftwood for them to slowly rasp away at and hide under.


Nowadays all good aquarium stores have freezers with frozen fish foods. These include various mollusks, fish, crustaceans, and aquatic insects. None of them are inexpensive. Most of them you can make yourself with a food processor and a trip to Shun Fat (see above), but frozen adult brine shrimp (discussed below) and blood worms (midge larvae) are more difficult to come by and could be considered for purchase at the pet store.

Blood worms are named because of their red color (it has nothing to do with blood) and can be collected from local ponds (see below) but never in quantity. They are an excellent food and highly recommended as a dietary supplement for all fishes.


The live foods sold by local pet stores include feeder guppies and goldfish (discussed below), live adult brine shrimp (also discussed below), and black worms (Lumbriculus variegatus). Black worms are an annelid worm, related to both the earthworm and the tubifex worm (Tubifex tubifex). The tubifex worm is another worm that can be considered along with them since they are essentially identical in their aquarium characteristics. Both worms are aquatic but are found in very high nutrient bottoms. They are most often found in open sewers and therefore have a correspondingly bad reputation as disease carriers. Commercially sold black worms are however byproducts of the trout hatching industry, and so they are unlikely to give you something nasty like cholera. Black worms and tubifex worms were mentioned in the June 1998 issue of The Calquarium, where Steve Ward took a rather dim view on their use. I however have a less pessimistic opinion on them. I have in the past fed black worms to my cichlids about once every month or so, and have never seen any bacterial diseases as a result. They are also a very good food for bottom grubbing fish like Corydoras catfish and elephant noses (Gnathonemus petersi). In fact, one is hard pressed to keep elephant noses alive at all without a sand bottom and a steady supply of black worms. Cautions are in order however as black worms are very high in protein and fat, and so they cause problems if fed too often. The worms must be stored in the refrigerator with daily changes of cold water.


Many live foods can be raised at home, and the culture of lived foods is a huge topic in its own right. I’ll just mention a few foods and try to direct you to more information. A good place to start is in the CAS library, which has a book called the Encyclopedia of Live Foods. This book covers almost all the topics discussed below and several more.

Some fish (for example the Chaca catfish) are so highly predatory that they specialize in feeding only upon other fish. For these predatory fishes you have little choice but to either raise feeder fish yourself or buy them in bulk. Goldfish (Carassius auratus) are the traditional feeder fish to buy. However, goldfish, while inexpensive, are a bony fish with tough scales. Only very large fish can handle them. Most people who raise feeder fish raise guppies (Poecilia reticulata) or some other livebearer. These are smaller and softer than goldfish and thus more suitable for a wider range of predators. But guppies aren’t very prolific, casting off only about 30 babies per month per female, so it’s hard to keep enough guppies on hand. Egg scatters like the Danio species would provide many more offspring per female. Or a prolific cichlid like the convict (Archocentrus nigrofasciatum) would produce nearly as many babies as danios but (being larger at hatching) they would be a lot easier to raise to an eatable size. Always feed your feeder fish before their final swim so the predator gets extra nutrients from the food in its prey’s stomach.

Compost worms (Eisenia foetida) are great for larger fishes and can be chopped up for smaller fishes or processed into a jelly food like that of the recipe given above. They will also get rid of your vegetable table scraps. Raise them in a compost bin. Learn more about worms on the Internet at or in Dwayne Tiede’s July 1998 Calquarium article. Compost worms are available locally from The Compost Queen (ph. 282-4765).

White worms (Enchytraeus albidus) can be grown along with your compost worms as well. These are smaller than compost worms and so are good for smaller fish. The classic technique to collect white worms is to place a milk-soaked slice of white bread on top of the compost and leave it overnight. The worms will gather under the bread and can be scraped off in the morning. More information on white worms is on the Internet at White worm starter cultures are often auctioned at club meetings or they can be mail-ordered from

West Kootenay Tropical Fish Hatcheries
PO Box 109, 705 Griffin Avenue
Slocan, BC, V0G 2C0
(250) 355 2592

Wingless fruit flies (Drosophila sp.) are another good food source for adult fish. They are especially suitable for top feeders like archerfish (Toxotes jaculatrix) and African butterfly fish (Pantodon buchholzi). Starter cultures can be mail-ordered (e.g. from Ward’s Natural Science Establishment, Inc., at 1-800-387-7822, Raise fruit flies in mayonnaise jars stopped with a foam rubber plug or covered with a piece of cloth and a rubber band. Dissolve one teaspoon of molasses and a pinch of baker’s yeast in five tablespoons of water, then mix in three tablespoons of instant potato flakes. Put the resulting glop into the jar with ten or so adult flies, cover, and you’ll get a few hundred flies within a couple of weeks. Learn more about fruit flies at or in the September 1997 issue of The Calquarium where you will find an article about them by Doug Forsyth.

Baby brine shrimp (Artemia spp.) are the perfect food for almost all baby fish, and small adult fish such as tetras as well. Very small fry (like those of most egg scatterers) can not eat brine shrimp immediately, but larger fry (such as livebearers’ and most cichlids’) can start out on brine shrimp. Brine shrimp are hatched in salt water from commercially available dry eggs. They are usually hatched in some sort of funnel with an airstone at the point of the funnel. An inverted plastic 2-liter pop bottle with the bottom cut off works well. Learn more about brine shrimp at or check out the Calquarium articles by Ernie Inglis and Dan Grimbly in the April 1993 and April 1994 issues (respectively). Brine shrimp eggs are available at local pet stores.

Microworms (nematodes) are another good food for fry, and can be fed to smaller fry than can brine shrimp. Microworms can be raised in plastic containers on a mixture of corn meal, water, and baker’s yeast. Learn more at or in Paul Price’s Calquarium article of March 1993. Microworms can be collected from their culture containers with a Q-tip as they will cling to the sides. Just dip the Q-tip in the aquarium with the baby fish to feed. Microworms can be acquired at club auctions or from the West Kootenay Tropical Fish Hatcheries.

Very small fry, like those of tetras and bettas, often have a hard time with even microworms. To these fry, “infusoria” is often fed (infusoria is an old word for Protozoa that aquarists still use). In the past raising infusoria was a hit or miss affair because the techniques all relied on the organisms finding their own way into the culture. Nowadays, pure Paramecium cultures are available by mail order (e.g. from Ward’s Natural Science Establishment, Inc.) and these are much preferred ways to get a culture going. Grow the paramecia in boiled and cooled water to which a few boiled wheat seeds and a pinch of brewer’s yeast is added. Small, sterilized plastic containers can be used to grow them, and a coffee filter can be used to filter them out of their culture water. A detailed description of Paramecium culture is in The Calquarium’s June 1996 issue, thanks to Richard Pon, and also at


It is possible to raise other live foods, but don’t bother. Go out and find some. It’s more fun. In fact, it can be a lot more fun, for now we are entering the realm of the bug hunter. For the bug hunt, you will need a large fine-mesh fish net. Preferably it has a long handle. Bring along a lidded bucket (to fill with pond water) so you can get your bugs home. A lot of people wear hip or chest waders when hunting, but heck, I just where a pair of shorts and some old sneakers and get wet. So obviously this is a job for a warm day. And be prepared to pick leaches off of yourself afterward.

You also need a good place to hunt. Any of the ponds around Calgary will do, but you would like one that is accessible without crossing private land or having to scale a fence. If you must go on private land, always ask permission. Tell the landowner you are doing a mosquito larva count for the university or something if you are embarrassed by your own eccentricity.

Local ponds are not supposed to be sprayed with insecticides anymore, but various farm chemicals might still cause problems. Do not choose a pond near a crop field, but instead just stick with cow pastures. And if a pond looks like it should have lots of bugs, but doesn’t, assume something is amiss and rather than hunting hard and long for whatever bugs that are there, just go onto another pond. The bugs may not be there because of something in the water that won’t do your fish any good either.

You want a pond with plant life in it, but not one that is so heavily overgrown that it is difficult to get to the water. Cattle in the neighborhood are a definite asset, because their droppings fertilize the water and this results in a much more abundant aquatic bug population.

Other subtleties should be considered when choosing a pond. For example, smaller ephemeral ponds or water-filled tire tracks (especially in cow pastures) are going to have lots of mosquito larvae and little else. Not that this is bad though, since mosquito larvae are one of the very best foods and feeding them to your fish is psychologically very satisfying. Mosquito ponds usually disappear by mid-summer but they can reappear any time if we get a good storm. Give the pond a few days after a storm to repopulate before collecting it. Mosquito larvae are air-breathers and can be easily seen rafting just under the surface with their tail-snorkels sticking out of the water.

Ephemeral ponds are also likely to have fairy shrimp (Streptocephalus seali). These look sort of like a larger version of an adult brine shrimp. They make a very good food but are relatively few and difficult to catch in bulk. Fairy shrimp can be reared in captivity but the lack of a commercial supply of eggs makes this much less convenient than rearing brine shrimp. Aquarists are forced to catch the adults and spawn them, which the adults readily do when their homes dry up. To collect eggs, put the shrimp in an aquarium and slowly lower the water, then allow the last centimeter or so to dry up on its own. Learn more about fairy shrimp at

Larger, longer-lived ponds are likely to have Daphnia pulex in abundance. Daphnia are pinkish in color and look like small spheres a couple of millimeters across. Close inspection shows that they have large black eyes and feathery antennae on their heads. A pond’s population of Daphnia can change dramatically even over a few days. When a pond is in a Daphnia bloom (often following the deposition of a fresh cow pie and a good solid rain), the density of Daphnia can be astounding. But after the population explodes it will inevitably drop again as the predator population increases, the water starts to dry up, and the oxygen levels decrease. Daphnia can be reared on a diet of yeast and finely ground spinach, but they are so easily caught that most people don’t bother.

Another live food local aquarists can find in abundance is fresh-water shrimp (Gammarus lacustris). These are discussed at the web site Gammarus inhabit flowing water and larger lakes, and are generally found among the stones of a cobbled bottom. In rapidly flowing streams they can be collected by kicking and shuffling among the stones while holding a net downstream of your feet, so the shrimps get swept into the net by the current. They can also be collected by scraping the bottom with the net, but this is wears out the equipment quickly. Gammarus make good food for larger fish like cichlids, but they are too large and tough-skinned for smaller fishes. They can also swim remarkably quickly. Dropping a few Gammarus into a cichlid tank really livens things up.

Other bugs will also end up in your catch, but I never worry about parasites entering the aquarium with the bugs. The only real problem you are likely to introduce with the bugs are Hydra, which are a predator of very small fish fry. My tank does have a few Hydra, but I’ve never lost any fry to them and so I don’t worry about it. But if you have very small fry or a lot of Hydra, a double dose of Aquari-sol given on two consecutive days will rid your tank of them, as was discussed in Birgit McKinnon’s article in the April 1996 issue of The Calquarium. All the other fry predators (dragonfly nymphs etc.) will be eaten by larger adult fish. When feeding bugs to small fish, however, screen any large bugs out of the food carefully. This is most easily done by passing the catch through a wide-mesh fish net, and feeding the fish whatever passes through it. Pond snails and leaches should be stuck to the sides of your collecting bucket by the time you get home so they aren’t likely to end up in your tank. But if you see any, pick them out.

Some of your bugs won’t survive the trip home, depending on how many bugs are in the collecting bucket’s water. But don’t worry about any die-off. When I get home I dump the bucket’s contents through the catch net to filter the bugs out of the pond water. I then quickly rinse the bugs in cold tap water before giving my fish one good feeding of live bugs. Then I freeze what’s left. I never bother trying to keep a bug catch alive for more than one feeding.

As far as diseases go, I’ve never seen or heard of any being introduced in this way so I never worry about them.

Collecting live food was the topic of Calquarium articles in the July 1998 and April 1993 editions.

So that’s about all you need to know about foods. Have fun feeding!?