Creating the right environment in your fish tank is important for long-lasting enjoyment and the overall health of your aquarium. To do this, you need to understand the various aspects of the aquatic habitat you’re building. You need to think about the right balance of light, substrate, lighting, filtration, and temperature to list only some of the many variable conditions involved.
A fish you may want to consider adding to your tank is the Otocinclus. This breed of freshwater catfish will add many benefits to the environment inside your aquarium. These fish, also called Otos or Dwarf Suckers, come in a variety of species and colors. They originate in South America and live in the many smaller rivers that spread across places like Venezuela and Argentina.
Species Overview
| Common Name: | Dwarf Suckers |
| Scientific Name: | Otocinclus |
| Family: | Loricariidae |
| Origin: | South America |
| Adult Size: | 4-5″ (10-12.5 cm) |
| Average Lifespan: | 10 years |
| Temperament: | Peaceful, but may eat small fish |
| Diet: | Herbivorous – Consuming plant matter |
| Minimum Tank Size: | 40 gallons |
| Reef Compatible: | Yes |
| Care Level: | Moderate |
| Breeding: | Difficult |
Benefits Of Otocinclus
The reasons to consider adding Otocinclus to your aquarium are simple enough. They’re attractive fish with calm and sociable personalities who fit in well with the majority of freshwater community tanks. They are also well known for being algae eaters and will help you maintain and control the algae growth in your tank. Overgrown algae are unsightly and can cause problems for plants, fish, and other creatures. Keeping it under control is important, and doing so by using natural means like fish who eat it is the healthiest and least obtrusive way to do this.
Another benefit of adding Otocinclus to your tank is that they’re not temperamental or difficult fish to care for. They’re great for those who are amateur fish tank owners and those who are still learning. Depending on the species you choose, they don’t cost a great deal. Aquarium owners on a budget will be able to enjoy these compatible fish without spending a fortune.
Otocinclus Behavior
Otocinclus enjoy being in a community. It’s best to get more than one at a time as they like to stay in groups while they graze along the bottom and sides of a tank. Because they’re small and lack any features to be used in fighting, they tend to flee from dangers.
They can move quickly despite their usual calm nature and will probably surprise you with how fast they are. During their time in your tank, you’ll notice they stay out of the way of the other fish and are happy to just eat all day.
Like some other varieties of catfish, the Otocinclus is capable of breathing air for a short period of time, though since they are happiest near the bottom where the algae are more plentiful.
Otocinclus Appearance
Similar to most catfish, the Otocinclus is shaped like a cylinder that narrows at the head and tail. Their mouth is positioned underneath them for grazing on the bottom and sides of the aquarium. They have sturdy scales to protect them from abrasions so they can latch onto rocks and gravel. It also offers some shielding from other fish who may try to nibble or bite them.
The males and the females look very similar, and it’s sometimes difficult to tell them apart. Males are typically narrower and smaller, while the females will be wider and larger. Because the width is the easiest way to sex them, looking down from above them is usually best.
Their coloration and patterns will depend on the species of Otocinclus you choose, but they’re all fairly nice in appearance while not being too flashy. They will go nicely in most freshwater tanks because their coloration is not obtrusive and won’t detract from the overall aesthetic.
Types Of Otocinclus
There are around 19 different species of Otocinclus, each unique and interesting to look at in its own way. The five predominantly popular species to find in an aquarium are the Dwarf Oto, the Common Oto, the Golden Oto, the Silver Oto, and the Zebra Oto. Some of these species are obvious in appearance based on their name, but some are not, and there are a few that will be challenging to tell from one another.
Dwarf or Otocinclus Macrospilus
These are a speckled brown color over their back to blend in with the natural silt and dirt of the river beds, while their bellies are white. The Dwarf Oto has a dark stripe that runs along the side of its body and a unique spot on its tail.
Common or Otocinclus Vittatus
This is the most common species you’ll see of the Otocinclus and has a similar mottled brown body and light-colored underside to the Dwarf variety. However, the dark stripe down its side continues up to the tip of the tail.
Golden or Otocinclus Affinis
While the Golden Oto looks almost identical to the Common Oto, its brown speckled body is closer to a gold color, and the speckling is less obvious.
Zebra or Otocinclus Cocama
In a nice contrast to the three previously listed brown varieties, the Zebra Oto, or sometimes called the Tiger Oto, has contrasting black and white zebra stripes along its sides. They can make a striking appearance in tanks decorated with more subdued and earthy hues.
Silver or Otocinclus Vestitus
If you were to take the Common Oto and replace the speckled brown coloration with more silvery tones, you would have the Silver Oto. They even have the same darker stripe along the body to the tail.
Otocinclus Tank Setup And Needs
To prepare your tank for these fun little fish, you’ll want to pick a fine substrate for the bottom. While they do have decent scaly protection for abrasive surfaces, using coarser gravel may be too much for them and cause scraping that can lead to health problems and stress. They spend a lot of time on the bottom, so you’ll want it to be comfortable.
Because algae like light, so do the Otocinclus. Having plants and rocks to decorate is fine, but you’ll want to limit it to allow their favorite food to grow and create a more natural environment. You also don’t want it to be too sparse. They need a secluded place to hide when they are frightened or stressed.
The pH levels should fall in the neutral range, and the water should be warm and in the mid to high 70-degree range. Although many freshwater fish need an air pump, the Otocinclus lives in naturally slow-moving rivers and will do fine without one.
Otocinclus Tank Mates
Otocinclus get along well with most non-aggressive fish. They keep to themselves and don’t bother other creatures in the tank. The one thing you’ll want to watch out for are larger fish who may think they look like an easy target. The Otocinclus is small and could become prey for something larger. A good way to understand if a companion fish may become a problem is if its mouth is large enough to swallow an Oto.
Fish like Guppies, Tetras, and Angelfish will be fine with Otocinclus as a neighbor and won’t intrude on their space either. You can also look to shrimp and snails for some decent variety in the tank atmosphere.
Otocinclus Dietary Needs
As already mentioned, the Otocinclus love to eat algae. They’re herbivores and rely on grazing all day along the bottom and sides of the tank. While they primarily eat algae in their natural habitat, your tank may not provide enough to satisfy them. Using algae wafers can help them get enough, and there are other options as well.
If you’re the type who likes to provide your fish with fresher foods, you can give them some green vegetables. You can chop up spinach, zucchini, and Brussel sprouts for a few fresher options if the algae look low. Because these things can muck up your tank and create an unclean environment, make sure to remove the uneaten bits after a day.
Because Otocinclus is a fish that feeds itself, it may be tricky to know how much you need to supplement their diet. The best way to know for sure is by watching the algae growth levels since that is their main source of food.
Possible Health Concerns For Otocinclus
The Otocinclus is a hearty and simple fish. It doesn’t require much extra or special care and is a great way to keep your tank healthy. They’re also perfect indicators of the overall health of your tank. If you have Otos and you still see an excess of algae, you know something is wrong with the cleanliness of the aquarium.
Things to watch out for are similar to most freshwater fish, like tail rot, lich, and eye cloud. If you find any sort of ailment with your fish, the likelihood is that the water chemistry is wrong or something is causing unusual stress. This should be addressed right away as these things will affect everything living in your tank, not just the Otocinclus.
Otocinclus Breeding
Even though these fish are fairly easy to please when it comes to food and habitat, they aren’t so easy to please when it comes to breeding. Where Otocinclus are usually content, they are picky with the environment they chose to propagate in. Of course, some fish will be more particular than others, but generally speaking, they will want everything just right before their ready to breed.
A good sign is if you see your males chasing around your females. If they’re doing this, it probably won’t be long before you see their egg clusters huddled in floating vegetation. Many breeders will remove the female ready to breed into a separate tank with one male, then move the pair back once the eggs are laid. This is because they can be so temperamental about water chemistry, and there is some thought that they may even eat their own eggs under the right conditions.
In one breeding cycle, a female will lay about ten eggs. Once the eggs hatch, it’s best to feed them algae and infusorians. Although some will feed the fry brine shrimp, it’s best to wait until they’ve grown a bit to make sure there won’t be any problems. Once they’re about half an inch long, it should be safe.
If you decide you want more Otocinclus in your tank and are able to breed them, it’s a good idea to try. Many of these fish are caught in the wild and then sold, creating stress where there doesn’t need to be. A staggering number of aquarium fish die this way before they even make it to someone’s tank, so reducing that intrusiveness if you’re able is a good way to become more familiar with these fish and create a healthier way to maintain them.
Conclusion
Otos are a great fish to have in almost any freshwater tank. They act as indicators of the health and conditions of your aquarium and are perfect in community environments with a variety of other fish and creatures. They have a great temperament and can be attractive additions while still blending in nicely with the vegetation and tank decorations.
They’re easy to care for and come in a variety of species that give you options in their coloration and appearance. Because they’re small in size, they do well in smaller tanks and won’t be a nuisance to other fish. Overall, they’re a good fit for most freshwater aquariums.
