Grade school science taught us that snails are gastropods from the large mollusk family, said to contain over 50,000 species. The more familiar creatures belonging to this family are the octopus, squid, cuttlefish, clams, oysters, scallops, mussels, and snails. What differentiates snails from other members of the family is that snails have a single shell that protects their soft bodies. Snails are found in land and in water. Since there are a number of aquatic snails, these mollusks often find their way in the home aquarium whether you like it or not.
They may or may not be a wanted inhabitant of your aquarium. Some fish keepers deliberately put snails in their tanks. For one, they do eat algae on the aquarium glass, plants, driftwood, and the surfaces of your tank decorations. In fact, the Ramshorn snail is a popular addition to the planted tank. These snails with planispiral or “flat coil” shells are a favorite among planted tank enthusiasts because of their efficiency in controlling algae growth, and because of their docile behavior, they do not destroy the tank setup. Secondly, I must admit they are cute. Thus Ramshorn snails are a good addition to your tank.
However, there are other kinds of snails that find their way into a tank which are not much revered by fishkeepers. The two most common kinds that we Filipino fishkeepers encounter are the pond snail and the Malaysian trumpet snail.
Pond snails have oval shaped shells that are dark brown to black in color. The shell may be plain or have some spots on them. The shell is spiral with the tip normally the highest point, but generally, the overall shape is oval. The pond snail can move quite fast for a snail, and will be all over your tank. You will see them at the bottom, all over the glass panels, all over the plants, driftwood, and decorations and even traversing the water surface upside down with their “feet” facing you, skimming just below the water surface—yes, they can grip the water surface!
The Malaysian Trumpet snail is long and conical in shape. They are called thus because their shell resembles the shell trumpets (horns) used by some seafaring indigenous people. The shell is hard and pointed; the tip can actually hurt or scratch you if mishandled. They mostly stay at the bottom and you will hardly see them on the glass panels. They in fact burrow in the substrate, which is actually a good thing since this behavior aerates the substrate and prevents anaerobic conditions that can harbor bad bacteria.
But what gets the ire of fishkeepers about pond snails and Malaysian Trumpet snails is their efficiency in multiplying. In no time, your tank will be infested by these invertebrates. They will overrun your tank with sheer numbers and will look unsightly and downright ugly. I have had tanks with so many pond snails that the first thing you notice are the snails and not the fish inside it, or with Malaysian Trumpet snails for substrate since they are all littered at the bottom.
The thing is, it’s likely you will never introduce these snails to your tank. You’d Probably opt for the nicer Ramshorn, Nerite, or even Apple snails, which are prettier; you can even keep some as pets. But with pond and Malaysian Trumpet snails, that is highly improbable. They are simply pests, not pets!
HOW THEY INVADE YOUR TANK
If you did not introduce pond and Malaysian Trumpet snails into your tank, how do they get there? Chances are they were introduced by accident. The most likely source of accidental introduction is through plants. Oftentimes, plants carry pond snails or their eggs, and these are unnoticed by the fishkeeper. Pond snail eggs are tiny white eggs enclosed in a clear gel and are normally located on the undersides of plant leaves, so they are quite easy to miss. Malaysian Trumpet snails do not lay eggs but give birth to young; the larvae are tiny, hard to see, and may be lodged among the root system of plants.
Therefore, if you buy aquatic plants from a store and don’t check the leaves, stems or roots for snails or eggs, there is a big chance you will introduce these nuisances to your tank. By the time you notice these critters have invaded your tank, they will be in numbers that will test your patience.
Like they say, an ounce of prevention is better than a pound of cure. Thus it is better to prevent introducing pond and Malaysian Trumpet snails into your tank. Carefully inspect and wash plants before introducing these to your tank. Some fishkeepers even recommend dipping the plants in a light bleach solution to kill snails and eggs. Others recommend putting the plants in a quarantine tank and being sure they are snail-free before using these in your aquarium.
Malaysian Trumpet snails are most likely introduced when buying used substrate from other fishkeepers. In today’s era of easily selling used aquarium stuff online, there is a big chance of having Malaysian Trumpet snails in your tank if the substrate itself is infested with these snails. Malaysian Trumpet snails are known to survive long periods in damp substrate. Thus, there is a big chance of having these snails suddenly show up in your tank if they were merely hidden in the substrate. So visual inspection may be difficult or may prove inefficient with Malaysian Trumpet snails.
OPTIONS FOR WHEN PREVENTION FAILS
But if, in spite of your best preventive efforts, you one day find your tank infested with a colony of snails, what should you do? There are many ways of removing snails from your tank.
The first method is quick and easy but rather crude. Simply pick off what you find and dispose of them. Not very efficient, but this method is, at the moment, the quickest way. If you see one, just dip your hand in and pick the snail up. There is no way a snail will outrun you. This is victory in an instant! But you can only go as far as what you can see and pick up. Tiny snails are hard to pick up with your fat fingers.
For revenge, you may set up a 20-gallon tank and keep a puffer fish. Throw in any snail you happen to grab inside this tank. Puffer fish love eating snails. In fact it is recommended to offer them snails because their specialized teeth grow constantly and if they are not given food with shells, they will develop an overbite. Giving them snails and other hard food will trim their teeth, preventing the overbite from occurring.
If you have a snail infestation, then picking them up may become a tiring chore. Thus setting a snail trap will be more effective. Put a leaf of cabbage or lettuce in the tank at night and pick this up in the morning. By then there should be a number of snails clinging on to the leaf. You can then remove the snails from the leaf and put them into the puffer fish tank. You may also use a small net baited with sinking pellets and remove the net in the morning. But the other fish may also fall for this trap; just let them out before removing the net. This method may be unsightly, though, which is why I recommend setting this up at night and removing it in the morning.
Another option which can prove more efficient at massacring your snail infestation is using chemicals to kill the snails. There are many aquarium products available for this purpose. Use as directed and you should be able to kill a lot of snails. However, I am not a big fan of this as the chemical is still a poison. Thus, an overdose may affect the fish in your tank. Second, this will create massive snail death in your tank, which in turn will increase the bioload of your tank. Finally, you will have tremendous number of empty shells in your tank, which will be unsightly.
THE PREDATOR LIST
The option which I prefer the most is introducing predators in the tank. There is no fear of accidentally poisoning the water, merely a compatibility issue. But for fishkeepers, this is a concern we are all knowledgeable about.
There are some fish that are built to eat snails. The Puffer Fish is one, but the thing with these fish is they may also eat other fish in the tank. They may be cute and adorable but one bite can cut a fish in half. So they may not be a good choice. The Pinstripe Damba or Paretroplus menarambo is another efficient snail eater, but the P. menarambo is a large cichlid that grows to 12 inches in length, is quite pugnacious, and hardly available. This rare cichlid from Madagascar is known to be extinct in the wild. I would suppose you would rather set up a P. menarambo tank that would be your pride and joy rather than as just a snail eater.
In my opinion, the best fish that can rid your tank of snails are the loaches. However, not all loaches are efficient snail eaters. One example is the Kuhli loach (Pangio kuhlii). Well, they are small and cute and really cut out to be well mannered and not destined to be serial killers of snails. If they do feed on snails, they don’t clean them up as effectively as others.
The best snail eating loaches are the botia-related species. They are efficient in ridding your tank of snails. There are a few species that are regularly available in the Philippine market. Some of the popular ones are the following:
• Orange-finned loach (Yasuhikotakia modesta). This loach should be available in the market at any given time. The body is generally brownish grey or silver grey in color with orange fins. Some stocks are dyed blue and given the trade name Blue Botia. This is the same fish species, merely artificially dyed blue. The Orange Finned Loach grows quite big, up to 10 inches, with a notorious attitude. It can be aggressive and territorial with other fish. So this is a good recommendation for a snail eater with medium to large tank inhabitants.
• Yoyo/Pakistani/Lohachata loach (Botia almorhae). This loach is known by many names in the hobby, but locally, they are known by these three names. The base body color is silver to beige with black “scribbles” on the body. It is a modestly sized loach and grows to about 5 to 6 inches. They are peaceful, pretty, and highly recommended as a snail eater in most tanks. Their availability in the country, however, is seasonal, so you must take advantage of getting some when they are available.
• Skunk loach (Yasuhikotakia morleti). This is a small loach that grows to about 3 or 4 inches and usually arrives in the country at 2 inches. But don’t let its small size fool you. Skunk loaches are known to be aggressive and territorial, and it is believed that they can’t tolerate each other as well. It has a light brown base body color with a black band that stretches from the tip of the mouth and traverse the back up to the peduncle. Another black band crosses the peduncle from the top and narrows to the bottom. The Skunk loach is also seasonally available and is quite rare compared to the others.
• Dwarf Chain loach (Ambastaia sidthimunki). This is a loach that rarely is available in the Philippines. At a maximum size of 2.5 inches, it is the best snail eater for a small tank with small fish. It is also a very beautiful fish. The general body color is silvery white to light brown. A chain link pattern from the nose to the tail adorns the upper part of the body which sometimes extends down to the belly. If you are able to see some in a fish store this is always a good buy whether you use it as a snail eater or the star of your tank.
• Clown loach (Chromobotia macracanthus). In my opinion, the Clown loach is the best snail eater for everyone. It grows to a maximum size of 16 inches, but is available in the Philippine market as small as 2 inches to as large as 12 inches all year round. Thus, getting some at the size you prefer is always possible. So if you happen to need some because you have a snail infestation, you can just rush to your favorite fish store and get some. They are peaceful and extremely attractive. With its orange base body color with 3 vertical V-shaped bars, it can easily steal the show in your tank.
Another snail predator that has become increasingly popular the last few years in the country is the Assassin snail (Antentome helena). Yes, it is a snail, and a beautiful one indeed. Its trumpet-like shell is light brown to gold in color, with black stripes. It is very attractive and is a good addition to the tank. The Assassin snail preys on other snails, keeping the numbers of pest snails low. And since they reproduce at a much slower rate, they do not infest your tank the way Pond and Malaysian Trumpet snails do. But I bet that even if you have an infestation of these beautiful snails, you would not mind because you can sell them as well.
This story appeared in Animal Scene’s October 2016 issue.