Otocinclus Catfish Care Guide: Appearance, Lifespan, Food & Diet, Breeding & All | 2024

By: Martin McAdam
Updated: September 26, 2022

Otocinclus is a genus of small freshwater catfish in the family Loricariidae native to South America. They are commonly referred to as “otos” or “dwarf suckers.” They are found in slow-moving waters of streams and rivers, where they scrape algae from rocks and other surfaces using their suckermouths.

Otos are also very popular in the aquarium hobby and are considered one of the easiest fish to care for. And they are often used in aquariums to help control algae growth.

Lastly, they’re a breeze to breed in the home aquarium, making them an excellent choice for those looking to start their breeding program.

This guide will provide you with everything you need to know about Otocinclus Catfish, from their natural history and behavior to how to care for them in the home aquarium.

So, let’s get started!

Species Summary

Scientific nameOtocinclus Vestitus
Common nameDwarf suckers, otos
FamilyLoricariidae
OriginSouth America
HabitatFreshwater streams, rivers
OriginSouth America
Size1.5-2 inches
Life span3 to 5 years
Tank sizeAround 10 gallons
Temperature72-79 degrees Fahrenheit
pH range6.8 to 7.5
Water typeSoft to hard
Tank matesAny small fish
Water hardnessEither soft or hard
TemperamentPeaceful
Care typeEasy
DietFeed on algae
Ease of breedingEasy to breed in the home aquarium

When it comes to choosing a freshwater fish for your aquarium, Otocinclus Catfish make an excellent choice. They are peaceful, easy to care for, and prolific breeders. And they are one of the few fish that will feed on algae, making them ideal for tanks with live plants.

So, if you’re looking for a low-maintenance fish that can help control algae growth in your aquarium, then Otocinclus Catfish is a great option.

Otocinclus Catfish Appearance

Otocinclus Catfish are small, torpedo-shaped fish. They have a dark brown to black body with a light-colored stripe that runs down the center of their back.

Otocinclus Catfish Appearance

They get their common name, “otos,” from the Latin word “oto,” meaning “ear,” due to their small, round ear-like plates that are located just behind their eyes.

Otos have a small head and mouth with a sucker-like disk on the underside of their body to attach themselves to rocks and other surfaces. Their small size and peaceful nature make them popular for freshwater aquariums.

These fish have a regular cylindrical body with a forked tail. Both dorsal and anal fins are relatively short, and pectoral fins are located low on the body. The fish has a larger sucker disk on its underside.

One common trait you’ll find in all varieties of Otocinclus is their small size. While most fish in this species only grow to be 1.5-2 inches long, there are some that can reach up to 6 inches in length. The largest recorded Otocinclus was just over 7 inches long.

The males are usually smaller than the females and have more elongated fins. So, if you’re looking to breed Otocinclus, be sure to purchase a group of 6 or more fish and allow them to pair off on their own.

Otocinclus Catfish Size & Growth Rate

Otocinclus Catfish are small freshwater fish that typically grow to 1.5-2 inches in size. Most varieties of Otocinclus are small, except the O. macros plus, which can reach up to 6 inches in length.

Otocinclus Catfish Size & Growth Rate

They are a relatively slow-growing fish that can take up to 2 years to reach their full size. They can be kept in tanks as small as 10 gallons.

Some of the minor Otos measures would be just 1.2 inches long.

Otocinclus Catfish Lifespan

These fish can live for 3 to 5 years when cared for properly. This lifespan can be even longer in some cases, with some fish living for up to 7 years.

Like any animal, the lifespan of an Otocinclus Catfish can be shortened by poor water quality and inadequate care.

You should always consult with a veterinarian or fish expert if you have any questions about the care of your fish.

Otocinclus Catfish Breeding

Otocinclus Catfish are relatively easy to breed and can be bred in a home aquarium.

Otocinclus Catfish Breeding

You will need an aquarium of at least 20 gallons with a good filter to breed them. The tank should be heavily planted with lots of dense vegetation. You will also need a few spawning mops or plants to provide a place for the eggs to attach.

The breeding process begins when the male and female become interested in each other. They will start swimming together and displaying their fins to each other. Eventually, the male will start courting the female by nudging her body and underside it with his head.

If you want to induce spawning artificially, you can raise the water temperature to 82°F and add a bit of aquarium salt to the tank. Once the female is ready to spawn, she will lay a few hundred eggs on the plants or mops. The male will then fertilize them.

After about three days, the eggs will hatch, and the fry will be free-swimming. They will need to be fed small, live food such as brine shrimp or Daphnia.

Otocinclus Catfish are usually ready to breed at around six months old.

Otocinclus Catfish Behavior & Temperament

As already stated, Otocinclus Catfish are very social creatures and will often shoal together. This means they should be kept in groups of at least 5 fish.

Otocinclus Catfish Behavior & Temperament

Otocinclus Catfish are also very active fish and will often swim around the tank in search of food. They are peaceful fish and will not bother other tank mates unless they are being harassed or bullied.

They are very shy fish and will often hide when they feel threatened. It is important to provide them with plenty of hiding places in the tank, such as caves, plants, and driftwood.

Otocinclus Catfish are also very sensitive to environmental changes and should not be moved to a new tank unless necessary. And even then, be sure to do so gradually.

They can swim very quickly and often dart around the tank when feeding.

Also, check: Pipefish 101:Care, Appearance, Diet, Breeding, Lifespan & All

What Are The Different Types

There are many different types of Otocinclus Catfish, but some of the most common include:

Common Otocinclus (Otocinclus Vittatus)

One of the most widespread and common types of Otocinclus, the common oto, is found in various habitats throughout South America. This small fish has a dark brown to black body with a light stripe down its back. It typically grows to 2-3 inches in length.

Zebra Otocinclus (Otocinclus Cocama)

The zebra oto is a small, black and white striped fish native to the Amazon River basin. This variety of Otocinclus typically grows to 2-3 inches in length and is one of the most popular types kept as pets. The fish also has a light stripe that runs down the center of its back.

Brazilian Otocinclus (Otocinclus Affinis)

The Brazilian oto is a small, brownish fish found in the Amazon and Paraná River basins in South America.

Green Otocinclus (Otocinclus Arnoldi)

The green oto is a small, green fish found in the Amazon River basin.

Spotted Otocinclus (Otocinclus Mariae)

The spotted oto is a small, brownish fish with black spots that are found in the Amazon River basin.

Golden Oto (Otocinclus Affinis)

The golden oto is a small, yellow fish found in the Amazon River basin. This variety of Otocinclus typically grows to 2-3 inches in length. Sometimes mistaken for ordinary goldfish, this variety is a member of the catfish family.

Silver Otos (Otocinclus Vestitus)

The silver oto is a small silver fish found in the Amazon River basin. These fish are hard to find and are becoming more popular in the aquarium trade.

Dwarf Oto (Otocinclus Macrospilus)-

The dwarf oto is a small, brownish fish in the Amazon River basin. However, upon closer inspection, you’ll notice that this fish has a series of dark markings on its body that give it a “dwarf” appearance. This variety of Otocinclus typically only grows to 1-2 inches in length, making it one of the smaller types of Otocinclus.

While there are many different types of Otos, they all share a few common traits. They are all small, peaceful fish that do well in community tanks. They are also relatively easy to care for and make an excellent choice for beginner aquarists.

Otocinclus Catfish Care Guide

The recommended care for Otocinclus Catfish is pretty straightforward. These fish generally spend a lot of time hiding and prefer to stay in groups, so be sure to provide plenty of hiding places in your tank. Driftwood, rocks, and plants are all excellent options.

As far as tank mates go, Otocinclus are peaceful fish that do well in community tanks. Good choices include other small, peaceful fish. Avoid keeping them with larger, more aggressive fish as they may bully or harass the Otocinclus.

Otocinclus are relatively easy to care for when it comes to caring for and make an excellent choice for beginner aquarists. However, there are a few things you’ll need to keep in mind to ensure your fish stay healthy and happy.

Otocinclus are also known as “algae eaters,” so you’ll need to provide them with a diet that includes plenty of plant matter. Algae tablets or wafers are a good option, but you can also feed them blanched vegetables or frozen algae.

It’s also essential to keep your tank clean. Otocinclus are sensitive to water quality and prefer a tank with clean, well-oxygenated water. Be sure to perform regular water changes and vacuum the gravel to remove uneaten food or waste.

If you’re looking for a peaceful, easy-to-care-for fish, then Otocinclus Catfish is a great choice. With proper care, these little fish can thrive in your home aquarium for 2-3 years.

You may also check Silver Dollar Fish 101: Care, Diet, Appearance, Breeding & All.

Food & Diet

Otos are considered herbivores, and, in the wild, their diet consists mainly of algae. One way to provide your Otocinclus Catfish with a healthy diet is to blanch some vegetables and feed them to your fish. This can be done by boiling the vegetables for a few minutes and then cooling them down in ice water.

Otocinclus Catfish Food & Diet

Some good options include:

  • Zucchini: This vegetable is high in vitamins A and C.
  • Spinach: This vegetable is high in protein and iron.
  • Broccoli: This vegetable is high in vitamin C and calcium.
  • Romaine Lettuce: This vegetable is high in fiber and vitamin A.

You can also feed your Otocinclus Catfish commercial algae wafers or pellets. These products are designed to provide your fish with the nutrients they need to stay healthy. Be sure to read the labels of these products carefully to ensure that they are suitable for herbivores.

As with all animals, it is important to provide your Otocinclus Catfish with a varied diet. You can also feed them a commercial diet designed for herbivorous fish. This can be found at most pet stores.

Be sure to keep a close eye on your oto’s diet and make changes as needed to ensure they get the nutrients they need.

Diet Foods To Avoid

There are some foods that you should avoid feeding your Otocinclus Catfish. These foods include:

  • Eggs
  • Meat
  • Fish
  • Insects

Above all, it is essential to remember that Otocinclus Catfish are herbivores and should be fed a diet that consists primarily of algae. Avoid feeding them eggs, meat, fish, or insects, as these foods are not a part of their natural diet and can cause health problems.

Feeding Schedule

When it comes to feeding your Otocinclus Catfish, it is important to follow a schedule. This will help to ensure that they are getting the proper nutrition and will help to prevent overfeeding.

A good feeding schedule for oto’s is as follows:

  • 1-2 times per day
  • Feed them a small amount of food at each feeding.
  • Only feed them as much as they can eat in 2-3 minutes.
  • Remove any uneaten food from the tank.

Tank Size

When it comes to tank size, Otocinclus Catfish can be kept in tanks as small as 10 gallons. However, for optimum health and happiness, it’s recommended to provide them with a tank of at least 20 gallons. This will give them plenty of space to swim and hide.

Plants should be added to thicken the aquarium and provide hiding places for the fish. As these fish are sensitive to water quality, be sure to use an aquarium filter and perform regular water changes.

Water Parameters

In their native South American habitat, Otocinclus Catfish live in water with a pH of 6.8-7.5 and a temperature of 72°-79°F. They can tolerate a slightly wider range of pH (5.5-8.5) and temperature (65°-86°F), but it’s important to try and match these as closely as possible in order to maintain their health.

The water hardness for Otocinclus should be kept at soft to moderate levels, with a KH of 2-8 degrees and GH of 4 -12 degrees.

Otocinclus also require high levels of dissolved oxygen, so be sure to use a quality aquarium filter and keep the water agitation to a minimum. Blackwater conditions are ideal for these fish, so if you can replicate these in your tank, even better!

It’s also important to change 25-50% of the water every week and vacuum the gravel to remove uneaten food or waste.

And in addition to regular water changes, you’ll also need to perform a partial water change every month using an aquarium-safe conditioner to remove any harmful chemicals from the water.

Filtration

When it comes to filtration, Otocinclus Catfish are not too fussy. A good quality aquarium filter will provide them with the high levels of dissolved oxygen they need and help keep the water clean and well-oxygenated.

You should also aim to keep the water agitation to a minimum to avoid stressing out your fish.

In terms of water flow, Otocinclus prefer a moderate to high flow level in their tank. This can be provided by an aquarium filter or powerhead.

Some recommended filters for Otocinclus Catfish include:

  • Aqua Clear 50-70: These filters provide good water circulation and filtration for tanks up to 70 gallons.
Aqua Clear
  • Fluval 205 Canister Filter: These filters are great for larger tanks and can accommodate up to 100 gallons of aquariums.
  • Tetra Whisper In-Tank Filter: These filters are a good option for smaller tanks and can be used for up to 10 gallons in aquariums.
  • SunSun HW-302B: These filters are a good option for larger tanks and can accommodate up to 150 gallons of aquariums.
  • AquaTech pf20/30: These filters are great for larger tanks and can accommodate up to 200 gallons of aquariums.

Heating

Otocinclus Catfish are tropical fish and require a heater in their tank to maintain a consistent water temperature. The ideal water temperature for these fish is 72-79 degrees Fahrenheit.

When choosing a heater, be sure to select one that is appropriate for the size of your aquarium. Some recommended heaters for Otocinclus Catfish include:

  • Eheim Jager Aquarium Thermostat Heater: These heaters are a good choice for small to medium-sized tanks.
Eheim Jager Aquarium Thermostat Heater
  • Fluval E Series Electronic Heater: These heaters are a good choice for larger tanks.
  • Hydor ETH Inline External Heater: These heaters are a good choice for larger tanks.
  • Tetra HT Submersible Aquarium Heater: These heaters are suitable for small to medium-sized tanks.

Lighting

Otocinclus Catfish do not require special lighting and can do well in a variety of lighting conditions. However, providing them with low to moderate levels of light is generally recommended.

If you’re using fluorescent or LED lighting, aim for a light spectrum that is similar to natural daylight. This will help replicate their natural habitat and make them feel more comfortable in their tank.

Some recommended lighting for Otocinclus Catfish include:

  • Aqua-Tech 6500K Daylight Bulbs: These bulbs provide a bright, natural light that is perfect for replicating their natural habitat.
  • Zoo Med Aquarium Hood: This hood provides low to moderate levels of light.
  • Fluval Sea CP1 Circulation Pump: This pump provides a gentle flow of water.

Co2 System

Otocinclus Catfish come from blackwater environments and do best in tanks that mimic these conditions. One way to replicate blackwater conditions is to use a CO2 system.

CO2 systems help lower the water’s pH and make it more acidic, which is similar to the natural habitat of Otocinclus Catfish.

If you’re interested in using a CO2 system, be sure to speak with an aquarium specialist to find the best option for your tank.

Some recommended CO2 systems for Otocinclus Catfish include:

  • AquaticLife CO2 System: This system is a good option for tanks up to 75 gallons.
  • MarineLand CO2 System: This system is a good option for tanks up to 120 gallons.

Substrate

Otocinclus Catfish do well in various substrates but prefer a dark, organic-rich substrate that mimics their natural habitat.

Some recommended substrates for Otocinclus Catfish include:

  • Aqua soil Amazonia: This soil is perfect for creating a blackwater environment in your tank.
  • Black Diamond: This substrate is a dark, organic-rich soil perfect for Otocinclus Catfish.
  • Tropica Aqua Soil: This soil is also perfect for creating a blackwater environment in your tank.
  • Aquascaping: When aquascaping your tank for Otocinclus Catfish, be sure to create a dark, shady area for them to hide. These fish like to stay hidden away during the day and will come out to feed at night.

Some plants that are perfect for creating a dark, shady area include:

  • Java fern: This plant is a hardy, low-maintenance plant that is perfect for Otocinclus Catfish.
  • Cryptocoryne wendtii: This plant is also hardy, low-maintenance plant.

Decorations

When choosing decorations for your Otocinclus Catfish tank, be sure to select items that will provide them with plenty of hiding places. These fish like to stay hidden away during the day and will come out to feed at night.

Some recommended decorations include:

  • Driftwood: This is a perfect decoration for providing hiding places and creating a natural-looking environment.
  • Rocks: Rocks can also provide hiding places and help to create a natural-looking environment.
  • Caves: Caves are another great option for providing hiding places and can be used to create a variety of different aquascapes.

Other Tank Accessories

In addition to the decorations and substrate, you’ll also need some other tank accessories to create the perfect environment for your Otocinclus Catfish.

Some recommended tank accessories for Otocinclus Catfish include:

  • Thermometer: A thermometer is a helpful tool for keeping an eye on the water temperature.
  • pH test kit: A ph test kit is helpful for keeping track of the pH level in your tank.
  • Water conditioner: A water conditioner is necessary to treat tap water and remove harmful chemicals.

One of the best things about Otocinclus Catfish is that they are easy to care for and can be kept in a variety of different tank setups. Whether you have a small or large tank, these fish are a great option for beginner and experienced aquarists alike.

Be sure to provide them with plenty of hiding places and a dark, organic-rich substrate, and they will thrive in your tank.

Water Changes

Otocinclus Catfish are very sensitive to water quality and should have their water changed on a regular basis. It is recommended to do a 20-25% water change every week.

When performing a water change, be sure to use a gravel vacuum to remove any debris from the substrate. This will help to keep the water clean and clear.

After the water change, be sure to add a water conditioner to remove any harmful chemicals from the tap water.

Cleaning The Tank

Otocinclus Catfish are very sensitive to the levels of ammonia and nitrite in the water and should be kept in a tank that is free from these harmful chemicals.

It is important to clean the tank on a regular basis to prevent the build-up of ammonia and nitrite.

When cleaning the tank, be sure to remove any uneaten food or debris from the substrate and tank walls. You can use a gravel vacuum to remove any stubborn debris.

Some recommended cleaners for cleaning a fish tank include:

  • Aquarium cleaner: This is a chemical-free cleaner that is perfect for cleaning a fish tank.
  • Algae scraper: An algae scraper is perfect for removing stubborn algae from the tank walls and substrate.
  • Net: A net can be used to remove uneaten food and debris from the tank.

Cleaning The Filter

Otocinclus Catfish are very sensitive to water quality and should have their water changed on a regular basis. When cleaning the filter, be sure to remove any debris or build-up that has accumulated on the filter media. You can use a toothbrush or a filter brush to clean the filter media.

Replacing The Filter Media

It is important to replace the filter media regularly to keep the filter functioning properly.

When replacing the filter media, be sure to soak it in a bucket of water for 30 minutes before placing it in the filter. This will help to remove any dust or debris from the media.

Testing The Water

It is important to test the water regularly to ensure that it is safe for your fish.

Some recommended tests for checking the water quality include:

  • Ammonia test: This test measures the level of ammonia in the water.
  • Nitrite test: This test measures the level of nitrite in the water.
  • pH test: This test measures the pH level in the water.

These tests can be performed using a variety of different test kits. With regular water testing, you can ensure that your fish are living in a safe and healthy environment.

Common Possible Diseases

Otocinclus Catfish are very sensitive to water quality and should be kept in a tank that is free from ammonia and nitrite. If these levels become too high, it can cause stress and illness in your fish.

Some common diseases that can affect Otocinclus Catfish include:

  • Whitespot disease: This disease is caused by a parasite and can cause the fish to lose their appetite and become lethargic.
  • Dropsy: This disease is caused by bacteria and can cause the fish to swell up and lose their scales.
  • Fin rot: This disease is caused by bacteria and can cause the fins to become red and swollen.

If you notice any of these symptoms in your fish, be sure to take them to a vet for treatment.

Preventing Diseases

The best way to prevent disease is to maintain a clean and healthy environment for your fish. Be sure to perform regular water changes and clean the tank on a regular basis.

It is also important to quarantine new fish before adding them to your tank. This will help to prevent the spread of disease.

When changing the water in your tank, be sure to use a water conditioner to remove any harmful chemicals from the tap water.

Treatment And Medications Of Diseases

If you notice any signs of illness in your Otocinclus Catfish, be sure to take them to a vet for treatment.

Some common treatments and medications for diseases include:

  • Ammonia remover: This product is used to remove ammonia from the water and can help relieve the fish’s stress.
  • Aquarium salt: This product can be used to treat a variety of different diseases and can help to relieve stress in the fish.
  • Antibiotics: This product is used to treat bacterial infections and can help to restore the health of the fish.

If you are unsure about which product to use, be sure to consult with your vet. They will be able to recommend the best course of treatment for your fish.

With a little bit of care, you can keep your Otocinclus Catfish happy and healthy for many years to come.

Also check: Cardinal Sulawesi Shrimp 101: Care Guide & Breeding Guide

Cleaning Up After Your Oto’s

Otocinclus Catfish are very messy eaters and often leave bits of food and algae behind on the tank floor.

Be sure to remove any uneaten food or waste from the tank after a few minutes to prevent it from decaying and polluting the water. You can also use a gravel cleaner to siphon any waste or debris from the bottom of the tank.

Be sure to clean up after your ottos each day to keep the tank clean and healthy. This can be done using a soft brush or a siphon.

Handling

Otocinclus Catfish are very fragile fish and should not be handled unless absolutely necessary. If you must handle them, be sure to do so gently and avoid stressing them out. Be sure to use a soft net when catching them and avoid grabbing them by the body or fins.

If you must move them to a new tank, do so gradually over the course of a few days.

Tank Mates

Otocinclus Catfish are very peaceful fish and will get along with most tank mates. However, there are a few things to keep in mind when choosing their tank mates.

First of all, oto’s should not be kept with fish that are too large or aggressive. They can easily be bullied or harassed by larger fish. They should also not be kept with fish that are known to nip at fins.

The best tank mates for oto’s are other peaceful, small fish that are also algae eaters. Good choices include:

  • Zebra Loaches: These loaches are very peaceful and will get along well with oto’s. They are also great algae eaters and will help to keep the tank clean.
  • Siamese Algae Eaters: These fish are also great algae eaters and will help to keep the tank clean. They are very calm and will not bother other tank mates.
  • Mollies: These fish are also peace-loving and will not fuss other tank mates. However, they are not good algae eaters and will not help to keep the tank clean.
  • Cherry Barbs: These little fish are very quiet and will not bother other tank mates. They are also great algae eaters and will help in tank cleaning.
  • Guppies: These fishes are also peaceful. However, they are not good algae eaters and will not help to keep the tank clean.
  • Corydoras catfish: These bottom-dwelling fishes are calm and make good tank mates for oto’s. They are also good algae eaters.
  • Bristlenose plecos: These small plecos are peaceful and make good tank mates for oto’s. They are also good algae eaters.
  • Kuhli loaches: These small fishes are very shy but make good tank mates for oto’s. They are also good algae eaters.
  • Harlequin Rasbora: These small, peaceful fishes are good tank mates for oto’s. They are also good algae eaters.

Fish To Avoid

Avoid keeping them with larger, aggressive fish or fish known to nip at fins.

Advantages Of Having Otocinclus Catfish In Your Tank

The first advantage of having oto’s in your tank is that they are great algae eaters. They will help to keep the tank clean and free of algae.

Another advantage is that they are very peaceful fishes. They will not bother other tank mates and can be kept with various fish.

Yet another advantage is that they are tiny fishes. This makes them a good choice for smaller tanks.

Disadvantages Of Having Otocinclus Catfish In Your Tank

The only disadvantage of having oto’s in your tank is that they are not good at competing for food. This means that they may not get enough to eat if there is a lot of algae in the tank.

Wrapping Up

As you can see, there are both advantages and disadvantages to having oto’s in your tank. If you are looking for a peaceful, algae-eating fish, then oto’s make a great choice.

However, if there is a lot of algae in your tank, they may not get enough to eat. So it is important to weigh the pros and cons before deciding whether or not to add oto’s to your tank. So what do you think? Are oto’s right for you?

Thank you for reading! I hope this article has helped you to make a decision about whether or not to add oto’s to your tank.

Disclaimer

AquaMarinePower.com does not intend to provide veterinary advice. We go to great lengths to help users better understand their aquatic friends. However, the content on this blog is not a substitute for veterinary guidance. For more information, please read our disclaimer.

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