October 27

Sarah Robertson

Dwarf Otocinclus Don’t Like to Be Alone- Here’s How to Keep Them Happy!

Dwarf Otocinclus Catfish are fantastic fish for any aquarium because they can help to keep your tank clean and clear, even if you don't have an algae problem. They use their sucker mouth to attack algae on the aquarium glass, plants, and ornaments.

In fact, they are considered one of the world's best algae-eating fish, and their ravenous hunger for algae makes them a veritable cleanup crew.  They originate in South American rivers that flow rapidly, so they like strong water currents (which can be obtained with good water filters or powerheads), excellent filtration, and lots of aeration in their homes. The rows of armor-like plating on Otocinclus Catfish's bodies distinguish them.

They are schooling fish that do best in groups of 3 or more. These are small catfish, growing up to a maximum of 2 inches in length.  Females are usually a little larger than males. Despite their small size, they have large appetites and love to eat algae (especially soft green algae), zucchini, cucumber, blanched fresh vegetables, and high-quality sinking pellets or wafers. While Dwarf Otocinclus Catfish are peaceful by nature, they can be nippy toward slow-moving fish with long fins.

To take care of your Otocinclus Catfish, provide them with a well-planted aquarium with plenty of hiding places. Driftwood and smooth rocks work well for this purpose. The water should be clean and well-filtered, with a moderate water current. These fish are sensitive to changing water conditions, so do regular partial water changes and keep an eye on your water quality. 

Dwarf Otocinclus Catfish are relatively easy to care for, but they are sensitive to poor water quality and can be susceptible to disease. To prevent disease, keep their tank clean and provide them with a well-balanced diet. When keeping Otocinclus Catfish, it's important to remember that they are tropical fish and prefer warm water. To know more about this fish before you buy one, read on for everything you need to know about caring for Dwarf Otocinclus Catfish.

Quick Facts about Dwarf Otocinclus

  • Scientific Name: Otocinclus macrospilus
  • Common Name: Common Oto
  • Family: Loricariidae, Subfamily Hypoptopomatinae
  • Origin and Habitat: Amazon River basin in Peru. Occurs close to the surface in small rivers and streams among dense marginal vegetation where the water is quiet and on floating plant thickets.
  • Max Size : Attains close to 1.5-2 inches (3.5 cm-5cm)
  • Minimum Tank Size: 10-gallon tank
  • Temperature: 75-82°
  • Hardness: Moderate
  • PH: acidic to slightly basic (pH 5 to 7.5) water
  • Life expectancy : 3–5 years
  • Diet: Herbivore
  • Social Behavior: Peaceful, schooling/shoaling.
  • Region of Origin: South America
  • Captive Bred or Wild: Wild
  • Breeding: Egg-layer
  • Compatibility: Plecos, catfish, schooling fish, livebearers, rainbowfish.
  • Tank Mate Options: Red Shoulder Severum, Rummynose Tetra, Geophagus sp. Red Head Tapajos

Dwarf Otocinclus Care

Dwarf otocinclus is one of the smallest freshwater fish in the world and are native to South America. They are a peaceful community fish that do well in both planted and unplanted aquariums. Dwarf otocinclus are bottom-dwelling fish and prefer slow-moving water. In the wild, they can be found in rivers, streams, and lakes. They are schooling fish, so it is best to keep them in groups of 6 or more.

Dwarf otocinclus are very sensitive to changes in water quality and parameters, so it is important to have a well-established and stable aquarium before adding them. They are also susceptible to disease, so a quarantine period is recommended before adding them to your main tank.

Dwarf Otocinclus Size

The dwarf otocinclus is a tiny fish that reaches 2 inches in length when fully grown. When viewed from above, females are larger and broader than males.

Dwarf Otocinclus Lifespan

The average lifespan of a Dwarf otocinclus in captivity is 3–5 years, as long as it is properly cared for.

Dwarf Otocinclus Food & Diet 

Otocinclus Dwarf are herbivores that will eat mostly soft algae, particularly diatoms, as well as blanched veggies like Zucchini (Courgette), Carrot, Potato, and Cucumber. If you don't see any algae in your aquarium, Otocinclus can be fed with algae wafers or vegetable-based flake food.

Dwarf Otocinclus Appearance

Dwarf Otocinclus Appearance 

It's not always simple to identify the species of oto in the home aquarium because there are many with quite similar patterns, and the names given to them in stores are frequently incorrect. An adipose fin is absent in the Otocinclus species, although it is found on the close relative Paratocinclus species.

The Dwarf otocinclus is similar in appearance to the typical otocinclus, although it has a large blotch on its tail and a lateral stripe that soon fades away before reaching the tail. The dwarf otocinclus has a tiny, cylindrical-shaped body and a strong mouth that clamps down on surfaces for feeding.

The O. macrospilus is smoky grey on the top half of its body, with a thick, but often broken, horizontal line that runs from the nose to the base of the caudal fin running down it. The caudal markings distinguish this Otocinclus from the similar Otocinclus vestitus.

On the O. macrospilus, there is a large black blotch at the base of the caudal fin, with two faint vertical black stripes down its tail end. This fish is sometimes mistaken for Otocinclus affinis. It's tough to determine the gender of dwarf otocinclus. Females are, however, somewhat larger than males.

Dwarf Otocinclus Behavior 

Otocinclus Dwarf Sucker Catfish are very calm fish. It may be kept in any aquarium of non-violent fish. They must be kept in a group of three or more, and the aquarium should have aquatic plants.

They're shy, reclusive fish with a unique feeding habit. When they sense danger, the fish are quick-swimming and dash about the tank seeking safety — they're naturally pacifistic and avoid conflict as much as possible.

Dwarf otocinclus catfish are mostly nocturnal fish that spend the majority of their time latching on to the bottom of the tank and grazing on algae in groups. They blend in well with their surroundings, and they are most at ease when surrounded by other otos.

Occasionally, dwarf otocinclus catfish swim to the surface of the water to breathe air, especially if oxygen is restricted.

Dwarf Otocinclus Tank Mates 

Dwarf Otocinclus are great fish for living in groups. There is, however, documentation of this creature sucking on the slime coats of sluggish-moving big-bodied fish like Angelfish and Discus. It's also because they were kept in starvation conditions in fish shops and have acquired 'bad habits.'

They are non-aggressive, sociable fish that can live with other non-violent fish, shrimp, snails, and living plants in a peaceful setting.

They are small, peaceful fish that are easy targets for large, predatory fish, like the Oscars and Cichlids. Don't put oto catfish in with fish that have aggressive temperaments or big-mouthed fish that may consume this little catfish species.

Dwarf Otocinclus catfish like to be in the company of similar-sized, non-aggressive fish, such as:

Other oto catfish - These sociable fish should be kept in groups of at least six.

  • Corydoras
  • Guppies
  • Angelfish
  • Mollies
  • Zebra loaches
  • Cherry barbs
  • Danios
  • Tetras
  • Harlequin Rasboras
  • Dwarf Gouramis

Dwarf Otocinclus Tank Setup 

The first step in creating a dwarf otocinclus aquarium is to choose the appropriate tank size. Because dwarf otocinclus are such small fish, they do not require much room.

A planted aquarium is a requirement. Make sure they're in sufficient quantities, 3 or more is ideal. It's best kept in a group of six or more. They are nervous fish that, unless kept in groups (in the wild, they school in groups of several thousand), can die from anxiety if kept alone. Small fish such as this one are prey for larger fish in the wild since they feed while resting on the water's surface.

Caring for Dwarf Oto catfish is simple as long as you replicate the fish's natural habitat in captivity. Set up a warm, freshwater tank with slow-flowing water and ensure that the fish have easy access to plenty of algae.

They are most often found in shallow, sluggish-flowing waterways with algae-covered surfaces and easy access to sunshine. This environment may be recreated in the aquarium with a suitable substrate, decorations, and plants.

For the foundation of your tank, choose a soft, fine-grain sandy substrate. Because they are bottom-dwellers that dig in the substrate, avoid using abrasive substrates that might harm the fish's body.

Driftwood, plants, and other decor elements, such as rocks and caverns, may be used to promote algae growth and provide refuge and hiding places. If the tank is maintained correctly, placing it in an area with direct sunshine during part of the day may aid algae growth by providing a greater food source for otocinclus.

The following are ideal tank conditions for Dwarf Otocinclus catfish:

The water should be slow-flowing, soft, and well-oxygenated freshwater.

A minimum of 10 gallons or 20 gallons for groups of more than 10 fish is ideal.

The temperature should be 72–79°F (22–26°C)

A soft sand substrate is best.

Live plants that grow quickly, such as Anubias or Java Fern. Decorations, such as driftwood and rocks, should be included to provide hiding places and promote algae growth. Direct sunlight during part of the day is beneficial for promoting algae growth.

Maintain pH between 5.0 and 7.5; hardness should be 5–15 dGH.

Poor water quality can be harmful to them, therefore a good filter is required to reduce nitrite and ammonia levels.

Standard aquarium lighting is sufficient.

To keep the water warm, you may need an aquarium heater.

Bubblers are not required, although they may be beneficial. They can be used to oxygenate the water.

Although they are hardy fish, they don't tolerate water fluctuations, so keep the water clean and constant to ensure that they are happy and stress-free.

Dwarf Otocinclus

Dwarf Otocinclus Breeding 

The Dwarf Otocinclus reaches sexual maturity at six to nine months of age. It's hard to raise the fish in captivity, and only experts should attempt it.

There's not much information available on how to breed oto catfish. A breeding tank should be set up with soft, acidic water and plenty of hiding places for the fry. The parents should be removed after spawning. It is understood that the tank water must be clean and that the fish should be fed a nutritious, protein diet in order to stimulate breeding. As a final note, raising the water temperature above 79°F encourages mating.

The males chase the females around the tank before fertilizing the females' eggs when they are ready to breed. The females deposit their eggs on vegetation and bogwood, which hatch a few days later.

Dwarf Otocinclus Fry 

As fry, Dwarf Otocinclus do best in a group of their own kind. They are not too difficult to care for, but they are very sensitive to water quality. A simple sponge filter will provide sufficient filtration and aeration for them. The fry will readily eat algae wafers and blanched vegetables. They also consume bacteria and other microscopic organisms in the water column.

To help prevent cannibalism, it is best to raise the fry in a separate tank. When they are big enough to be added to a community tank, they can be slowly acclimated over the course of an hour or two. With intermediate care, they can grow to be about 1.5 inches long.

Dwarf Otocinclus Diseases 

There are no known diseases that only affect Dwarf otocinclus, although the fish are susceptible to a number of common freshwater illnesses.

The most typical external parasite affecting  Dwarf Otocinclus is Ich, which is also known as white spot disease. The disease causes salt-like sprinkles on the fish's body and fins. Ich parasites cause fish to appear sluggish, rub their bodies against the tank's walls, and lose their appetites.

To treat Ich/Ick quarantine the diseased fish and use commercial treatments or aquarium salts according to the directions on the package.

Another common disease that affects Otocinclus is fin rot. Fin rot is caused by a bacterial infection, and the symptoms include frayed or ragged fins and darkening of the edges of the fins. If left untreated, fin rot can be fatal.

To treat fin rot, increase the water temperature and add aquarium salt to the tank at a rate of 1 teaspoon per gallon. After the fins have healed, reduce the water temperature and remove the salt from the tank.

If you notice any of these symptoms in your Dwarf Otocinclus, take action immediately to treat the illness and prevent it from spreading to other fish in the tank.

To prevent such diseases, maintain a clean aquarium, and be sure to quarantine new fish before adding them to your existing tank. A separate quarantine tank is the best way to ensure that new fish are not introducing diseases into your tank.

While purchasing a new Dwarf Otocinclus, look for fish that are alert and have clear eyes. Avoid fish that have any visible signs of illness, such as spots or frayed fins. A healthy fish will have a plump, firm body and should be active. It is also a good idea to purchase your new fish from reputable fish keepers who can provide you with a health guarantee.

Dwarf Otocinclus


How Big Do Otocinclus Get? 

Dwarf Otocinclus only grow to be about 1.5 inches to 2 inches(3.8 cm to 5.1 cm) in length. Though they are small, they are still hardy and robust fish that does well in most aquariums.

Do Otocinclus Eat Algae? 

Dwarf Otocinclus are known as excellent algae eaters. They will consume all types of algae. They are particularly fond of black beard algae.

How Long Do Otocinclus Live?

In captivity, Dwarf Otocinclus have a lifespan of 3 to 5 years. To live a long and healthy life, they need to be kept in a clean tank with good water quality. They also need to be fed a nutritious diet.

How Often Should I Feed My Dwarf Otocinclus? 

Dwarf Otocinclus should be fed 2 to 3 times per day. They are small fish with high metabolisms, so they need to eat frequently. To prevent overfeeding, only give them as much food as they can consume in a few minutes.

What is the Ideal Tank Size for Dwarf Otocinclus? 

The ideal tank size for a single Dwarf Otocinclus is 10 gallons (37.9 L). If you are planning to keep a group of them, you will need a larger tank.

How Many Dwarf Corydoras Are in a 10 Gallon? 

A 10-gallon (37.9 L) tank can comfortably hold a group of 3 Dwarf Otocinclus. To keep 6 or more of them, you will need a 20-gallon (75.7 L) tank atleast.

Do I Need to Quarantine New Dwarf Otocinclus? 

Yes, you should always quarantine new fish before adding them to your existing tank. This will help prevent the spread of disease.

When quarantining new Dwarf Otocinclus, be sure to use a separate tank. The quarantine tank should have the same water parameters as your existing tank. You will also need to provide the fish with food and hiding places.

Do Dwarf Otocinclus Like Sand or Gravel? 

Dwarf Otocinclus do not have a preference for sand or gravel. They will do well in either type of substrate. They prefer any soft substrate that will not damage their delicate barbels.

What is the Best Filter for a Dwarf Otocinclus Tank? 

The best filter for a Dwarf Otocinclus tank is a canister filter. Canister filters provide excellent filtration while being hidden from view. They are also very easy to maintain.

Should You Get an Otocinclus for Your Aquarium? 

Dwarf Otocinclus are fascinating, low-maintenance fish. If you have enough tank space and the correct water parameters for at least 6 bottom-dwelling algae-eaters, you should get Dwarf Otocinclus catfish.

If your tank has large or predatory fish that might harm the catfish, or you can't keep good water quality, don't get oto catfish. They're sociable, active fish that keep your tank clean and provide hours of entertainment.

Dwarf Otocinclus Catfish and Betta, are they compatible? 

The answer is yes, they are compatible. Unless they are starving, Dwarf Otocinclus are rather peaceful and will not attack your betta. However, this isn't the case for your betta. Even if they don't have any of the conditions that betta fish assault, he may still attack them.

Bettas are notorious for eating and harming other fish, so no fish is completely secure in a tank with them. You should understand your betta's disposition before adding a tank mate. If he's aggressive, you should keep him away from other fish and instead start a new community tank. If he's docile, then you can likely add a Dwarf Otocinclus to his tank with little worry.

Final Thoughts 

Dwarf Otocinclus are interesting and low-maintenance fish that make a great addition to a most freshwater aquarium. They are known as excellent algae eaters and will consume all types of algae. They have a lifespan of 3 to 5 years and should be fed 2 to 3 times per day.

A nutritious diet and a lot of hiding spaces are important for their care. If you have the correct water parameters and tank space, you should consider getting a Dwarf Otocinclus for your aquarium. Sand or soft gravel is best for their substrate, and a canister filter will provide them with the best filtration.

Dwarf Otocinclus are interesting and low-maintenance fish. You can get Dwarf Otocinclus catfish if you have adequate tank space and the appropriate water conditions for at least six bottom-dwelling algae-eaters.

They're sociable, energetic fish that keep your tank sparkling clean and provide hours of fun. If you are thinking about getting an Otocinclus for your aquarium, be sure to do your research first. They are a great addition to most aquariums.

Sarah Robertson

I am a passionate blogger who also happens to be a fish keeping enthusiast. Writing about my hobby is something that I absolutely love to do, and it's no secret that my chosen topic is always centered around fish keeping.

Sarah Robertson

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