the least appreciated
of all carnivorous plants, since their cultivation needs are drastically
different from terrestrial plants, as well as the fact that capture is rarely
seen, despite the full view of the bladders. Nonetheless, for the purist
who must have every CP he can obtain, or the aquariophile who is interested
in the unusual, these plants make wonderful additions to the collection.
Despite a wealth of information to the contrary, these plants are not overly
difficult to raise. There are several key issues which should be addressed,
but first, let's go over a couple of basic setups. Please keep in mind that
my experiences have almost wholly been with North American species, however,
the advice here should work quite well with aquatics from elsewhere. Remember
though, tropical aquatic Utricularia form no turions, and do not go dormant.
The absolute best home for aquatic Utricularia is an aquarium. For most species, a ten-gallon at least is necessary. Some, because of their size, need a substantially larger aquarium than this, unless you are willing to prune heavily once a week.
Good filtration is required. It keeps the water clean, and hinders the overdevelopment of algae. Power filters are considered the best for aquaria, but they do pose some problems for the Utricularia grower. Floating Utricularia will either get pushed into one corner of the tank, usually where the lighting is weakest, or get caught in the intake of the filter. Submerged Utricularia will also get caught in the intake. This can be bad for the motor of the filter, and any bits of plants will have to periodically be removed to insure a good flow for the filter. Box filters are a good choice where the fish load is extremely minimal. Probably best to use two at the same time, on opposite sides of the tank.
Sponge filters are necessary if you wish to create a "summer puddle" biotope, including such small animals as Daphnia, Cyclops, Planaria, Scuds, and other pond life. No fish can be added to this system or else you will lose the rest of the critters. This type of aquaria is virtually unknown in North America, but in Europe it is accepted as a viable alternative to the fish only aquarium, although it is still not that popular. It is very apt for the aquatic Utricularia. grower, since the beasties will nourish the plants.
The pH, at least for the North American species I have kept, is of fairly low importance. All the plants I have kept have thrived equally well between the ranges of 4.5 (acid) to 7.5 (alkaline). However, it is a well-accepted fact that lower pH supposedly hinders algae growth. I'm not too sure about this, since I have easily cultivated algae in jars with a very low pH. Nonetheless, any pH above 8.0 definitely leads to serious algal problems, because of the different and more pestilent species of algae that survive in that range.
Mineral content is another matter. Depending on your locality, the mineral content of the water can be very high. It can in fact be directly hazardous some aquatic plants, causing a kind of burn effect. This doesn't seem to be the case with the Utricularia I've kept. But another factor is that a high mineral content will very likely lead to algae problems. The minerals are what they feed on. If your water is high in minerals, using a 1:1 combination of tap water and distilled water should keep the minerals at acceptable levels. Rainwater can be used where fish are not present. Rainwater is usually acidic, and carries more impurities than you might be aware of (dust, chemicals). In time these could hurt your fish population. If you're going to use it to top up a jar, it may not be a bad idea to pass it through some filter floss and/or boil it, before using it.
Sand is the best substrate for submerged species of Utricularia, but its use in aquaria is to be cautioned. If fish or other large aquatic animals are present, their activities will continually disturb the sand, leaving the water permanently cloudy. The floating particles of sand will land on the plants and any decorations, becoming unsightly and hindering the growth of the plants. The deposited sand may also lead to algae growing on the plants themselves, and it can wreak havoc on the filter's functioning and mechanisms.
Aquarium gravel may be used, but avoid larger sized gravels. Submerged Utricularia are naturally buoyant, and will eventually float away from the substrate if it is too large. Ultimately, the best sized gravel consists of rocks about 1/4" in size on average.
Either sand, gravel, or a bare bottomed tank is sufficient for floating species, obviously. Do not use peat moss in an aquarium, unless you have it contained in the filter. Many folks put the moss in a tied up stocking. Peat moss in an aquarium as a substrate is a messy and destructive substrate.
Lighting should be medium to strong, depending on species. Most prefer strong lighting for good growth. Avoid overly strong lighting for floating species as algae will form too easily in their mats, and may overtake them.
Aquatic Utricularia love warmth! However for a variety of reasons such as algal and bacterial blooms at high temps, and dormancy, the best range would be from between 20-25°C. Below 18°C, and the plants begin developing turions. I have experimented with U. macrorhiza, and have found that temperature and not photoperiod is the key factor to turion production. My personal experiences with other temperate species suggest the same. I would think that tropical species would do poorly indeed below 18°C, and would perhaps die at 15°C.
Windowsill jars are a very acceptable way to keep floating species (not submerged ones). Once the plants are established, the jars require minimal maintenance, and in fact can be left unattended for weeks at a time. It is the pre-establishment time that is critical. I have found that most jars do best if filled with a generous quantity of floating Utricularia. At the start algae will still occur, but the bladderwort will easily outcompete it if there is enough plant material in the jar. Nonetheless, I prefer seeding my jars with a small microorganisms called Ostracods (more on this later). If you don't have a lot of floating Utricularia to start off with, it will require that you be vigilant. Until there is enough plant matter to fill a jar 1/4 full, a complete change of water (and I recommend changing the jar as well) once a week is probably the best way to avoid a surplus of algae. The plants should also be rinsed under lukewarm tap water to dislodge dirt.
Whatever the case, watch that a thick surface scum does not develop. This stops the gas exchange between the water and the air that is so critical to a proper mini ecosystem. If this happens, do a complete water change, rinse the plants, and do this as frequently as necessary until the problem stops. If only a thin scum or discoloration appears at the surface of the water, you may be best leaving it there for a time, watching it carefully, of course. I have noticed that, if the problem isn't too severe at the beginning, it often regulates itself eventually.
Rinsed sand, gravel, and peat moss may be used as substrates, or nothing at all. If using peat moss, wet it completely first, and use only that which sinks to the bottom. Any floating debris must be removed. Take care not to knock the jar once the plants are introduced, or else the peat will swirl all about the jar, much of it landing on the plants.
Keep the jar at a bright windowsill all year long. It is best not to change its' location during the colder months. Recovery from this disturbance can be slow and could threaten the system.
Although I really do not have any experience with aquatic Utricularia can be grown in artificial ponds, but dealing with problems such as algae and pests requires different methods. Because of the much larger volume and surface area, different interactions can occur in a pond system than a jar or aquarium. Best to research a general pond website, or pick up some of the various publications dealing with that subject. Pet stores and pool centers often have knowledgeable people to help you with your questions. Do keep in mind the general indications stated above as a guideline to keeping your Utricularia happy outdoors.
Either because someone wants fish in their aquarium, or because they are looking for an acceptable algae eater, it is important to consider some basics to prevent the disappearance of your Utricularia. Many kinds of fish can successfully be kept with Utricularia, and pose no problem. But some fish will eat the plant and others will continually disturb them by pulling, excavating the substrate, or even just by being too active. Research the kind of fish you have or are planning to get before introducing them to your plants.
Utricularia are wholly not recommended for the breeding tank, unless you want to be watching the fry get captured. A possible exception to this rule is U. gibba, which has bladders small enough that they are unable to capture the young of larger species of fish.
Algae eaters (sucker fish) comprise a great number of fish, some more suitable than others. Some are indeed quite effective algae eaters, but even so, they are not designed to pluck the algae off the small leaves of aquatic Utricularia. Nonetheless, they can be beneficial in keeping down the overall quantity of algae in a tank, which will reduce it's appearance on the plants. Beware though. Some algae eaters do not actually consume algae, and others will actually eat your plants.
The best species I can recommend are the following: Otocinclus spp, Peckoltia spp, Farlowella spp, and Ancistrus spp. Platys and swordtails are beneficial as well. Through their constant nibbling, they help to keep the plants clean. I am uncertain of the acceptability of using the standard Plecostomus (which is actually supposed to be a fish called Hypostomus punctatus, but in reality is probably a Pterygoplichtys sp!) If you're wondering why I went to all the trouble telling you that, it's because of this. Both Hypostomus and Pterygoplichtys make very good algae eaters, but the latter will most likely die within 6 months to a year. I'm not quite sure why, but I think it is usually because they do not receive enough food, which is hard to see with them. In any case, I am also unsure if these two species will also eat something so tender as a Utricularia, which I suspect they will.
Pond life can be both a boon and headache. I obviously can't go into too much detail here, but I will mention a few species of note. Bar none, my favorite pond critter for use against algae is the Ostracod, also called seed shrimp. These are small crustaceans that can be found in lakes, ponds, and temporary puddles. They can take a couple of months to establish themselves in a jar, but once they do, they keep most forms of algae at bay very well. Daphnia has been stated as being the best algae eater, but I think this is somewhat untrue. First of all, they are not browsers. They are continually swimming through the water looking for suspended (free floating) algae, as well as bacteria. And I have not had a good deal of luck keeping them alive in the past. Nonetheless, they do help to keep the water clear when present in sufficient numbers, and so merit being used in conjunction with other species. Cyclops may eat algae, I'm not sure. But I do know this: they are hunters, and will devastate any species that is small enough to capture. Avoid them if you want to keep small Ostracod or Daphnia species. Larger species I have have cohabited well with Cyclops.
Worms are always present in aquatic systems, natural or artificial. For the most part, they are harmless, but there are some species that can kill your plants. I know one species that looks like nothing more than vertically floating pieces of debris. I've never seen them on the plants themselves, but believe me, they will quickly make them go into decline.
Aquatic insect larvae could be used, but you risk an infestation of your home when they finally emerge as full-fledged insects. Most are harmless to the plants, and some, notably the mosquito larva, are effective algae eaters. As a group, they should be considered in the same manner as worms, useable with caution.
Don't forget that the beneficial species are also occasionally consumed, a hearty treat for your plants. In a well-established system, a balance is reached. If you find that your microorganisms disappear, it may be that you simply need to find a bigger species. Find a different pond or puddle, or even lake, and try to see if there is a better species available. Don't be afraid to experiment, but if you do, keep a control jar in which you never add any creatures. The plants in this jar can be used to restock another if something goes terribly wrong.
Shrimp are often referred to as being very good at removing algae from small pinnate plants such as Utricularia. I believe this to be true, though I have never put it to the test. The trouble is that they are very hard to keep in the home aquaria. They seem to prefer cooler temps, and they need a good mineral content in the water to keep their shells hard. At times, this can be incompatible with your Utricularia. Minerals contribute greatly to algal growth. There is also reason to believe that many of the shrimp sold in pet stores actually need slightly brackish (salty) water to survive well. On the flip side, they are cheap, so if you'd like to give them a try, you won't be losing much, and maybe you'll have more success than I have.
Snails are not recommended. Most species will eat your plants and those that don't will not benefit the plants either. They create more of a load on the tank than most creatures their size, which in itself can lead to more algae. One exception to all this is the trumpet snail. It spends the daytime buried under the substrate, and comes out at night. It is supposed to be considered a good algae eater, but I have never seen evidence of this, and in fact, I find them hard to keep alive.
Many snails are androgynous and/or viviparous (live bearing). It often only takes the addition of one snail to a tank to lead to a sudden over population in time. If you want to get rid of them, you will have to do so manually, because any preparation that you can use to kill the snails will probably also kill your plants.
Generally, if your plants have some prey to eat, they will not need fertilizers. The most common problem I'm aware of with aquatic Utricularia is water with a low iron content. Despite the ridiculously high mineral content of many municipal water supplies, many are exceedingly low in iron content. If your plants are starting to seem pale, changing to a yellowish hue, and are becoming more brittle than normal, you can add aquatic plant fertilizer to the water. This is available at most pet shops. Be sure to get a fertilizer that specifically contains iron, because not all of them do. A half dosage often works fine, which is good, because the other minerals are probably already present in sufficient quantities in your tank, and too much may lead to our old enemy, algae.
Can't help you, sorry! (but see update below!) I've never managed to get my aquatic Utricularia to flower, though I've seen the same species do it every year in the wild. Given my turion experiments, I suspect it has more to do with temperature and lighting intensity than with photoperiod. If you'd like to experiment, I'd suggest keeping the plants under very bright light, and under very warm conditions (30°C minimum). Flowers are produced on a scape that emerges a few inches from the water, so leave them enough room for this. Having never had the flowers, I'm not sure what pollination techniques are best for them (self-pollinating, artificial pollination or cross pollination) But if you do manage to get seed, then you have a second major problem. Utricularia seed seems very viable (I've collected 1/2 cup of mud from one lake that had Utricularia, stored some of it in the fridge for 1/2 year, used the remaining in a jar, and in both cases, young Utricularia come up in droves. But they are extremely fragile at this stage. Algae will overcome them at a point where it is hard for you to see that there is even algae present. Normally beneficial pond life (which is often present even if you haven't introduced any) can nibble the young seedlings to oblivion. I would recommend sowing or keeping seedling Utricularia in a bare bottom clean jar at a bright (not too bright) window until they are mature enough to be placed elsewhere. I could only see seedling Utricularia. surviving in an aquarium if it was absolutely clean, and a sponge filter was used.
Often found in fish medicines and algae treatments. To be avoided at all costs. Copper is a toxic substance that kills both the microorganisms and the plants as well. If you feel you must use such a treatment for what ever reason, try a reduced dosage, but sometimes even that is likely too much.
As stated so often above, this is the enemy! Well, yes and no actually. Algae is a normal part of any natural water system. It helps by taking up nutrients that would otherwise build up to harmful levels (which I suppose it true of any other major form of life) the problem for us as growers is that algae seems to thrive in our artificial systems (jars and aquaria) far better than any other plant. This is probably due to their simple structure, and the fact that there are hundreds of different species designed to cope effectively with a variety of different conditions.
In my mind, there are only 2 successful way of dealing with algae at home. One is to set up a system that keeps it in check. This can be done by using a very clean aquarium, or a jar that is already loaded with suspended Utricularia, which grow quickly enough to be able to keep the algae at reasonable levels. The other way is by using algae eating creatures.
If you have an algal problem, research the algae you have. A few can be eradicated simply by changing pH, mineral content, lighting, or temperature. Some very few can actually be manually removed. Green spot algae, which appears on the glass as, well, spots of algae, is generally considered harmless. I have found that they are often (but not always) precursors of the more offensive kinds of algae. I've never tried to eradicate green spot algae, which I think is all but impossible. But I do pay more attention when I see it, and never let it get out of hand. An aquarium scraper using a razor is the best way to remove it.
I hope this page will help
you. When properly cared for, aquatic Utricularia make interesting and
often beautiful decorations for the aquarium, or an interesting conversation
piece in the jar! Many tend to grow rather quickly, and can turn your
aquarium into a veritable jungle. In any case, they are carnivorous plants,
which in itself makes them a wonder to be admired, even if they are less
than obvious about it.
Within a year of writing the above, I was fortunate enough to have one of my floating species, U. gibba, flower for me. In the last month it has produced 3 yellow flowers on one scape, and is currently producing a second scape. It has been growing in nothing more special than a mayonnaise jar. At around the same time, a friend, Chris Teichreb from the Vancouver Carnivorous Plant Society, managed to have his U. gibba flower in an overflow tray that held some other CPs By comparing notes, I think we have figured out the keys to successfully producing flowers with floating Utricularia
Lighting must be bright, and the photoperiod should be around 12-16 hours a day. The temperature should be constantly kept between 25-33 °C. (closer to 33 is better). The actual chemical composition of the water does not seem to be important, although of course you want to avoid any extremes in pH or mineral content. That's one half of the trick
The other half is that floating Utricularia need to float, undisturbed, just under the surface of the water. In my setup, this was accomplished by allowing the Utricularia to almost fill the mayonnaise jar. At a certain density, the Utrics will force each other more strongly towards the surface of the water. They will become a tightly intertwined mass occupying the top 1/3 or so of the jar. It is vital that once they have achieved this state, they not be disturbed. Water additions and changes should be done very gently indeed!
Only those plants which are located in the top 1/2" or so of the jar will flower. Flowers seem to be more tolerant of lower humidity levels than your average CP plant, but it is still a good idea to make sure that they aren't allowed to become too dry either, as often happens under artificial lighting. A cover is recommended. It is still to early to tell whether my flowers have self seeded or not.
In my friend's tray setup, the plants grew until they became a thick mass of plants. The water level was never all that high, perhaps an inch or a little more. Occasionally, the water level was allowed to drop until the Utricularia were just moist, but the tray itself was almost dry. I have read many times that in the wild, floating Utricularia are observed to flower when they become stranded on moist land or Sphagnum moss. The bladderworts in the tray were virtually neglected, which supports my view that they should not be moved around by hand or current to successfully produce flowers.
I believe that this can also be accomplished in an aquarium or pond, however it will be much more difficult to provide the necessary conditions.
I also believe this flowering advice will work equally well for other species of floating Utricularia
I'm still working on learning how to flower submerged species of Utricularia
as well as how to best raise the seeds. Wish me luck, and I'll keep you
posted if anything new turns up.