The Armored Suckermouths Plecostomus, or "plecos," belong to the Family Loricariidae, the world's largest catfish family. They are known for their heavy armored plates and sucker-shaped mouths. Scientists use "L" or "LDA" numbers to identify plecostomus species, with over 500 numbers and more added annually. Some, like the L046 Zebra and L177 Gold Nugget plecos, are vividly colored and expensive. Many plecostomus can breathe air due to digestive tract modifications. Farlowella and Otocinclus catfish can be included in this group for care purposes.
Natural Habitat and Water Requirements
Most Plecostomus species are native to South America, with some in Panama and Costa Rica. They live in various habitats, though some have limited ranges, existing only in specific river parts. Many plecos live in fast-moving shallow streams and rivers, while others inhabit acidic black water or quiet, brackish estuaries. In high-flow areas, they use their suckermouths to attach to rocks and submerged trees to avoid being swept away.
Loricariid catfish are typically found in soft water with a low pH in the wild; however, many commercially raised species tolerate a wider range of water chemistry. A pH between 7.0 and 8.0, alkalinity between 3° and 10° dKH (54 ppm to 180 ppm), and a temperature between 74° and 80° F will suffice for most captive-bred species. If the aquarium is kept in a room below 74°, use an Aqueon Aquarium Heater to maintain the proper temperature. Wild-caught fish may require a temperature in the mid to upper 80s, a pH of 5.5 to 7.0, and alkalinity below 3° dKH (54 ppm), so research unfamiliar fish before purchasing. Maintain good filtration and do a 10% water exchange every week or 25% every 2 weeks using an Aqueon Aquarium Water Changer or Siphon Vacuum Gravel Cleaner. Treat tap water with Aqueon Water Conditioner before refilling your aquarium.
Housing and Behavior
With numerous suckermouth catfish species available, there is a suitable one for any aquarium size or fish type. The common pleco, Hypostomus plecostomus, can grow over 12" and needs at least a 75-gallon aquarium, while Otocinclus are content in a 10-gallon tank. Plecostomus tend to be secretive, so provide caves, hollow logs, and other size-appropriate hiding places. Moderate to good circulation should mimic the fast-moving rivers many species inhabit. Decorate the tank with driftwood for refuge and food.
Many suckermouth catfish are nocturnal, hiding in crevices or under overhangs during the day. However, some adapt to aquarium life and become more sociable, especially at feeding time. Loricariids are compatible with most aquarium fish, but tank mates should be roughly the same size. Large predatory fish may try to eat smaller plecos or Otocinclus, causing the catfish to become lodged in the bigger fish's throat. Large plecos can be safely mixed with smaller fish as they will not usually try to eat them.
Read also: The Diet of the Common Warthog
Dietary Needs of Plecostomus
While plecostomus and other suckermouth catfish are often sold as algae eaters, some species are carnivorous, feeding on carrion in the wild. Others feed almost exclusively on wood, so it is best to research the dietary needs of any species you buy. Aqueon Bottom Feeder Tablets, Shrimp Pellets, Tropical Granules, and Algae Rounds can all be excellent foods for these catfish. Because of their nocturnal habits, many experienced hobbyists target feed their plecos once or twice a week with tablet or disc foods given at night. For best results, feed a variety of high-quality foods and rotate your fishes' diet daily.
The trend is to just throw a few algae wafers in after lights out and think that that is enough supplementary food for them. Its not! A plecs digestive system is designed for a diet high in bulk fiber and low in protein, they need large amounts of vegetable/fruit matter and occasional protein. None but the largest tanks could support enough algae to feed even a medium sized Plec, and while enough algae would have bulk it is very low in nutrition. But you'd be horrendously hungry the rest of the time. Excellent daily vegetable supplements are, romaine, spinach and other leafy green lettuces (Iceberg is very high in bulk but very low nutritionally.) that have been blanched* first, cut/sliced zucchini, cucumber, sweet potato, broccoli stems, peas and beans (blanched and skinned), and others. Fleshy fruits of various types can be fed too, Plecs in the wild feed on fruit fallen into river from overhanging trees. It takes most Plecs a few feedings to discover and realize these are food, but after that there is no keeping them away. Some fish will even guard these foods to keep other fish away. I found it very hard when housed with other fish to get such delights as worms and small scraps of cut fish/shrimp, shrimp pellets and other sinking food tablets/pellets down to the Plecs. Other fish can be sooo greedy. *As stated above "Most Plecs are very opportunistic Omnivores", but some are primarily carnivore (e.g. Zebras etc), some vegetarian and others (e.g. Panaque etc) require wood (Yes, wood!) in their diet to survive. *Blanching; too quickly prepare a food by placing it in or pouring boiling water over it. For detailed profiles/specific needs of various Plecos I highly recommend these two sites.
Key Dietary Components
- Vegetables: Romaine lettuce, spinach, zucchini, cucumber, sweet potato, broccoli stems, peas, and beans (blanched and skinned) are excellent supplements. Avoid iceberg lettuce due to its low nutritional value.
- Fruits: Plecos in the wild feed on fruit fallen into the river from overhanging trees.
- Protein: While plecos need a diet high in bulk fiber and low in protein, they still need occasional protein.
- Wood: Some species, like Panaque, require wood in their diet to survive.
Feeding Strategies
- Variety: Offer a variety of high-quality foods daily.
- Target Feeding: Because of their nocturnal habits, target feed plecos once or twice a week with sinking tablets or disc-type foods at night.
- Competition: Be mindful of other fish outcompeting plecos for food.
Breeding Plecostomus
While the spawning behavior of many rarer species is not well known, a fair number of suckermouth catfish have been bred in captivity. They typically spawn in caves, with the male caring for the eggs until they hatch. Fry, or recently hatched fish, are voracious and must be fed frequently on a high-protein diet such as micro worms, brine shrimp nauplii, sinking tablets, or disc-type foods. For intentional spawning, set up a separate aquarium and feed breeders live or frozen foods for several weeks to condition them.
General Care and Maintenance
Plecostomus or plecos are not the most complicated species of fish to care for. The hardest part of keeping them is supplying the right environment and diet requirements.
Temperament and Behavior
Every Plecostomus is different and has a distinctive personality. Some plecos, like the Clown Plecostomus, are extremely shy and reclusive. Others, like the Bristlenose or High-Finned Pleco, can actively be seen glass-hanging and exploring the aquarium.
Read also: Omnivorous Starling
Lifespan
5-15+ years, depending on the variety of Plecostomus and overall health. Many factors can affect your Pleco's lifespan.
Size
Depending on species, some stay small, 3-4 inches, for example, Bristlenose, Rubbernose, Clown, or High-Finned Plecostomus. Other species may grow to an unmanageable size of 3+ feet. Readily available often sold young, and many are unaware of their aquarium requirements and nutritional needs. Do not purchase a Common Pleco unless you are fully aware of how big they can grow. Please do your research on the species available to you, and it's essential to know the potential size.
Common Mistakes in Pleco Care
One of the biggest mistakes is not providing a proper diet. Plecos are fantastic at helping clean and maintain the aquarium but do not rely exclusively on algae to feed them. They require a lot more to their diet than just cleaning rocks and glass. Plecos are omnivores, and along with plant matter, meat is an essential part of their diet. Providing a variety of foods and proteins will help ensure nutritional needs to promote proper health and growth. Again, research on the specific Plecostomus is imperative. Ensure you offer various proteins, fats, and carbohydrates is an absolute must; you must feed them like all fish species.
The Importance of Fiber
Fiber is an essential carbohydrate that is important to some plecos diets. The simplest way to meet this need for their diet is to have a driftwood piece to rasp on somewhere in the aquarium. Some plecos don't necessarily need wood through the years of talking to various fish stores and pleco keepers. However, some plecos need this fiber from the driftwood to aid in maintaining a healthy digestive system. To keep and care for a pleco, it is recommended to add a driftwood piece to your aquarium. They are nocturnal; whether they rasp or not, driftwood pieces will provide an excellent safety source by providing cover, causing lower stress levels.
Tank Setup
Researching the individual Pleco you choose to keep is fundamental when setting up the right environment for them to thrive. Each species requires specific needs that you will not know unless you do your homework. Writing an instruction guide for a perfect tank that works for every Pleco is challenging. However, there is some commonality that you can keep in mind and a few things that have been noticed that work well. Plecos love, love, love, and often find them around the filter input; they enjoy water flow. Providing an adequate number of hiding spots is essential. They are nocturnal species, and allowing them a dark period, turning off the light is very important. If you want a healthy Plecostomus, remember to feed them a varied high-quality diet, do not rely only on the algae on the glass. Adding a few pieces of driftwood to the aquarium will always be a great idea.
Read also: Feeding Your Degu
Water Parameters
- pH: 6.0-8.0
- Water Hardness: All plecos are cared for in hard water.
- Temperature: 72-80 degrees Fahrenheit
Tank Mates
The list of tank mates you can successfully keep with plecos is plentiful, depending on the potential the species you wish to keep will grow too. Plecos can be kept with Guppies and Neon Tetra, and a Common Plecostomus in a Silver Arowana tank.
Recommended Group Size
1 per tank is probably best. If a smaller species and available tank space, maybe two. If you have a male and female, there is a fair chance they will breed. Occasionally, a pleco was lost when putting two in the same aquarium because one was outcompeted for food, take precautions if you notice aggression or not eating.
Distinguishing Males from Females
The only information that can be shared regarding distinguishing males from females is the Ancistrus cirrhosus or Ancistrus Bristlenose Pleco. Ancistrus refers to the genus of the species; male members of the Ancistrus genus will have whiskery or prickly noses. These tentacles are interopercular odontodes, seen in mature Bristlenose Plecos males and rarely a trait you see in females of this species.
L-Numbers Explained
Sometimes when researching different pleco species, you run across L-numbers. All known species of animals are scientifically named, called Scientific nomenclature. However, sometimes recently discovered species are not adequately classified yet and referred to by a number. There are seven levels: Kingdom, Phylum, Class, Order, Family, Genus, and if you look in the top section under plecos Family, you see Loricaiidae, and this is where the L-numbers come from, followed by a number.