The common Pleco (Plecostomus) is a popular fish that belongs to the catfish family. Ironically, there is no such thing as a ‘common’ Pleco, but instead, the term is used as a catch-all phrase for several species that fall under this description.
If purchasing a Pleco, you may be buying a Suckermouth Catfish, Bristlenose Catfish, Sailfin Catfish, or Amazon Sailfin Catfish. Each of these species is loosely defined as a Pleco in the aquarium trade.
That being said, they all have similar habits and traits in addition to tank requirements, so for all intents and purposes of this article, they are being treated like one.
Plecos are notable for their diminutive size when purchased since they are usually sold as juveniles, but they can easily grow to nearly a foot or two in length (30-60 cm) over time. So do be aware that they can grow substantially when kept in proper conditions!
They are tropical freshwater fish that belongs to the ‘armored’ catfish family and are native to South American river systems.
Considered a highly active nocturnal fish, you can expect them to be less visible during the daytime as they will hide and remain inactive during daylight hours.
Why are they such a popular addition to tank communities? We’ll delve a little deeper as we go through this article.
Pleco Behavior
Whichever species you end up with when buying a Pleco, it is rarely advised to keep more than one.
They do tend to be peaceful with other fish in the tank, so they are not particularly bossy or aggressive with other fish on the whole. However, as adults, they can become quite aggressive, which is in contrast to their peaceful nature as juveniles. You need to be careful and wary of them hunting and possibly consuming other tank fish as they mature, so be attentive.
Plecos are quite territorial and generally do not tolerate the presence of another of their kind dwelling in their turf very well. The only exception is if you are certain that you have a Bristlenose Catfish; in this case, they can usually be managed in a pair or trio successfully.
They are generally timid fish during the daytime and will tend to hide in caves or a hidey-hole, where possible close to the bottom of your tank.
However, at night they light up with activity and can be seen eagerly sweeping the tank floor and sides of your aquarium, cleaning the tank as they move along. They use their suckermouth action and attach themselves to various points in your tank like the glass walls, rocks, and tank floor.
Although many pet stores will promote them as algae eaters, they are omnivorous and cannot be sustained on algae alone. You must be sure to contribute other forms of nutrition to the mix for your Pleco to thrive and be healthy.
Pleco Lifespan
Plecos are long-term, long-living fish and can easily live for 10-15 years, so be sure to have one only if you are certain that you plan on keeping fish as a hobby for some time.
The other consideration is tank size to help them have an optimum lifespan because as they age, they grow considerably, and if you do not have a large enough tank to accommodate them, it will impact them significantly.
We will discuss more on tank requirements a little later in this article.
Common Pleco Appearance
The vast majority of Plecos are brownish in color and have sandy-toned spots on their bodies.
Their coloring will be dependant on their environment, however.
They are known as ‘armored’ catfish because they possess bony plates on their bodies that look like armor that protects their soft flesh. These plates are in a four-row formation lengthwise but are not present as far down as their abdomens.
As we have mentioned earlier, they can grow up to 2 feet in length in the wild, but in most tanks can get up to 15 inches.
Their mouths are a classic ‘suckermouth’ shape that can adhere to surfaces as they filter and feed on algae and other tank debris.
Their body shape is long and elongated with sharply defined fins. The dorsal, pectoral, and tail fins are well developed and shapely.
The dorsal and anal fins, in particular, possess rays. The dorsal has one coarse ray with seven softer ones, and the anal fin has one coarse ray and anywhere from 3-5 soft rays.
Plecos have an interesting membrane on their eyes known as an omega iris that they use when wanted. During the daytime, the iris is closed, and it is capable of restricting light input to their retinas. At night, the omega iris opens when they embark on their nocturnal activities.
Common Pleco Habitat And Tank Requirements
For the healthiest fish, all aquarists should aspire to recreate their natural habitats as closely as possible.
Since Plecos are freshwater fish from swift-moving water, so it is important to keep water movement active. Their suckermouths help them hang on to surfaces even with a vibrant current.
Plecos are prolific in terms of bioload, so you need excellent filtration to handle their waste contributions.
These fish need a large tank to accommodate their size, and do not be fooled by suppliers who tell you they will only grow to the size of the tank provided. Their internal organs will continue to grow even if externally they cannot, so for the health of the fish, be sure you can provide adequate space for these large freshwater fish.
Let’s look at some specifics that are needed.
Tank Conditions
They enjoy powerful currents and highly oxygenated water levels, so air stones and even wavemakers can be beneficial to add to your tank.
Because they require such a large accommodation to be kept successfully, only more experienced aquarists should pursue having them. The large tank size alone means more expertise is needed.
Naturally, they exist in fast-flowing shallow streams and rivers in tropical climates, so the temperature must be monitored even though they are fairly hardy to temperature variation so long as it’s gradual.
In the wild, they love hiding places, and so you absolutely must provide a sheltered cave or hiding formation for them to spend the daytime in. Hollowed logs or flower pots turned on their sides are good options for hiding places.
They prefer heavy vegetation, and they will often be seen eating plantlike also, so chose varieties such as java moss, java fern, or any other sturdy fast-growing species that can be resilient to regular nibbling.
Driftwood is another huge component to having a Pleco as they like to chew on wood and should be provided with some that have been treated and leached of tannins.
Substrate should be fine to medium-sized gravel or soil with a mix of sand, and any live plantlife should be well anchored as it is well known that Plecos enjoy uprooting plants.
Another key point when keeping Plecos is to realize that they like to gulp air at the top of your tank. They are also prolific jumpers and can exit the tank if you don’t keep a lid on top.
A point to bear in mind is that if you find your Pleco on the floor, know that they can stay alive for some time outside of water, so it’s best to reintroduce them to the tank and gently hold them for a time to see if they are okay and can resume respiration.
Robust, high-quality filtration should be high on your list of priorities as these fish create a lot of waste. Canister or hang-on-back filters are ideal for this type of fish. Basically, you can tell yourself that no amount of filtration is too much.
Water changes will need to be at least 30-50% on a monthly basis minimum.
Water conditions should be noted and maintained as follows:
- pH of 6.5-7.5
- Water hardness between 10-25 dGH
- Temperature between 72-86 ºF (22-30ºC)
- Lighting can be kept median
Tank Size
The minimum tank size needed is 75-150 gallons per catfish (283-567 L).
So size matters if you plan on having this species for optimum health and growth.
They need a lot of active swimming space to thrive and prevent stress when they become active nocturnally. Keeping them interested and engaged is important for their health.
Choosing Tank Mates For Plecos
It’s very important to consider what is best for the fish species you choose to care for as an aquarist when considering tank mates.
Educating yourself and doing the research necessary to have a harmonious environment is a key aspect of being their caretaker.
These fish do not do well in the long term upon reaching maturity with peaceful or semi-aggressive fish. You would do well to have them flourish with other aggressive species.
Some excellent fish tank mate pairings for Common Plecos are:
- Cichlids like Oscars or Green Terrors
- Tetras
- Gouramis
- Corydoras
- Otocinclus catfish
- Mollies
- Platies
- Tiger Barbs
- Silver Dollars
Common Health Issues Of Plecos
Plecos are active and energetic fish that swim about and jump quite prolifically in your tank.
They do not have any specific diseases that are unique to the species. However, being tropical fish, they are prone to a few common afflictions of tank residents.
Ich is a parasitic infection that can happen to any aquarium-kept fish. White spots are what become noticeable and can lead to issues with respiration, so you must keep an eye out for those. While highly treatable, it’s best to catch early as it can otherwise lead to more serious conditions.
The other common disease is fin rot which, while not a serious ailment, is bacterial and can be easily treated using veterinarian prescribed antibiotics.
The best way to avoid either of these afflictions is regular and thorough water changes. Sticking to a strict schedule and following a routine is the easiest way to have healthy fish as a hobbyist.
How To Breed Plecos
Anecdotal evidence supports the notion that Plecos do not breed in captivity. If breeding fish is part of your plan as a hobbyist, then do not get your hopes up when it comes to Plecos.
First of all, as you would require a huge tank to accommodate two Plecos in the first place, the situational setup is rather rare. Secondly, sexing Plecos is another difficult endeavor, so just knowing if you have a mating pair is hard enough to top off the tank size.
Only a small percentage of experienced hobbyists have successfully bred Plecos, and the minimum tank size for a breeding pair would be 100-200 gallons.
They would require loads of hiding places to reduce the likelihood of aggressive behavior, as we noted earlier in this article.
Males chose a hidey-hole or cave to breed in and will entice the female into the cave once it is cleaned and he deems it attractive. If the female is suitably enticed, she will lay her eggs on the walls of the cave, and the male will then guard them once fertilized until they hatch.
Realistically though, breeding Plecos is best left to experts with sizeable tanks that can accommodate the enormous amount of space needed for a sexually mature pair. Even then, breeding success is not guaranteed.
Conclusion
To sum up, Plecos are a fine addition to a tank as long as you are willing to adapt and grow with it.
Being peaceful as a juvenile makes them easy to buy and have with your community at the start, but knowing that they grow and attain aggressive qualities means you need to ascertain how and when to change up their living quarters.
You should expect to upsize your tank to keep them healthy and monitor behavior with other fish to keep an eye on predatory activity.
All in all, they are a fascinating species to keep, and if you can commit to their long lifespan and tank size requirements, then they might just be the fish for you.
