The Common Pleco is one of the most commonly sold fish in the aquarium hobby. It is also one of the cheapest and hardest to kill. I am here to tell you all about this fish and its care required to keep it happy and healthy — but more importantly, I’m here to tell you why you should NEVER, EVER buy one of these fish! Yes, I said it. DON’T BUY COMMON PLECOS!!! I also want to state that for the purposes of this article, I will not differentiate between all the species such as Hypostomus plecostomus and the numerous species incorrectly identified as H. plecostomus, but just discuss the common plecos in general. A lot of publications mislabeled them for years, and many pet stores still do to this day.
A 23 inch common pleco sititng under a 4.5—5 inch firemouth for size reference.
Most common plecos are found natively in South America, but there are huge invasive populations now found in parts of Florida, Texas, Nevada, and they are even believed to be found in Wisconsin as well. This problem isn’t unique to the United States; other countries around the world have invasive populations of them too.
They devour vegetation and repopulate, completely taking over waterways and forever altering their biological balances. In Florida, their populations and devastating impacts have gotten so bad that they are even swarming and attaching to Manatee bodies to eat the algae off of their skin. How does this happen? Is it really just tons of inconsiderate and ignorant hobbyists tossing fish that are too big for their aquariums into the water? Well, yes, that is a part of it. Some are from fish farms that were devastated during storms. But the real question is — beyond climate — why are these common plecos taking over?
It is because the common pleco is an armored sucker-mouth catfish with a ravenous diet. Yes, armored. There are longitudinal rows of scales that act as a literal suit of armor, making this pleco pretty hard to kill and the complete opposite of easy prey for any would-be predators. It is omnivorous and feeds on algae, vegetation (yes, most of the aquatic plants in your aquarium and in the wild), small crustaceans, driftwood, and dying/dead fish. If not enough food is available, they have even been known to latch onto live healthy fish and chew on them as well.
2 common plecos donated to my shop, big one is 23 inches in length and the other is about 4 inches.
Because of its armored body and its semi-aggressive nature, these plecos typically do well in most aquariums, from community fish tanks all the way to aggressive African Cichlid tanks. It is a hardy fish and a great scavenger on the bottom of a tank. The best part? You can purchase them relatively cheaply and very small — usually under $10! Sometimes under $5! Some pet stores, usually big box retailers, will tell you that if you have an algae problem, these are the best solution because it will make quick work of the algae in your 10-gallon tank. They are right, it will! It will be great… for a while anyway. Until they outgrow your tank!
I opened my own pet store only recently (about 6 months now), and I’ve already taken in dozens of common plecos of all sizes — 2–3 inches, 12 inches, 17 inches, and yes, even one measuring 23 inches in length. I’ve worked in the industry for 25 years now, and I’m probably underestimating numbers when I say I’ve taken in hundreds and hundreds of common pleco “donations” over the years. And most of the time, the owner completely underestimates the size of the plecos. I had one lady tell me she was bringing in a 6-inch fish to donate, and when they arrived, they were easily over 18–20 inches. Another couple had told me they had 3 common plecos to donate that grew too big in their 125-gallon aquarium. They told me the fish were under 12″ in length, so I told them to bring a 5-gallon bucket. They showed up with 3 plecos, nose-down in the bucket, tails stretched out and flapping around — measuring 17 inches, 20 inches, and 23 inches in length.
Common pleco donations of all sizes in the Oscar tank.
The first problem most aquarists run into is that they are quite literally poop machines. They eat non-stop, but they also vacate their stomach at the same rate. Between this problem and the fact that they have a penchant for eating plants, a lot of aquarists bring them to me in a size range of 3–5 inches.
The next most common issue is that the pleco has grown too big for the aquarium. In some cases, it struggles to turn around or splashes water out of the tank. Most of the time, these hobbyists didn’t realize how big these fish would eventually get and were not properly prepared to care for them long-term.
Lastly, you have the plecos that come in measuring 14–24 inches in length. These fish are absolutely huge and should be kept in huge aquariums. These fish were usually housed in 125-gallon aquariums, sometimes 180s or even 210s — all too small for these fish in my honest opinion.
So, in conclusion, just stop it with the common plecos! I am talking to everyone here — importers, wholesalers, breeders, pet store owners, employees, and hobbyists alike. Stop bringing in, selling, or buying common plecos. Stop contributing to this problem. Most of all, if you can’t house your common pleco or any other fish, NEVER EVER RELEASE THEM INTO THE WILD. Take them to a pet store that will accept them, find a fellow hobbyist, or humanely destroy them. These fish have already shown how invasive they can be and how much damage they can do to local ecosystems!
As always, submit any questions, comments or requests to: PicKFishPets@gmail.com
