We hear this every day:

“Do I need a bottom feeder?”
“I need something to eat all the leftover food”
“I need one of those sucker things.”

The bottom feeder, or sucker-mouthed fish we will be referring to in this post is the Plecostomus. First, it is helpful to understand where the concept of “needing” a bottom feeder/suckerfish originated. The root of this myth stems from a time when filtration design was rudimentary and less was known about fish keeping and feeding practices. As the hobby grows there is an abundance of available research about aquatic life and the specific requirements of each species. Additionally, filtration, food, and other aquarium equipment continues to be improved upon which means that we can provide optimal living environments for our aquatic friends. The Plecostomus catfish family is a diverse and beautiful one, so let’s give them the understanding and care they deserve.

 

“Do I need a bottom feeder?”

When we hear someone ask this we of course know what they mean and it is our job to explain to them what the correct action might be. They are not entirely incorrect about asking for such a fish, they are simply repeating what they have heard in the past and what they have been told is true. We have ourselves stood in stores and listened to staff members tell their customers about how they should be buying a “suckerfish” for their tank as if it is second nature to do so without any explanation as to why they may need one or anything else resembling a scientific approach. The customer/hobbyist knows no better and they are relying on the person in the store give them informed information. At some point you aquarium may benefit from such a fish, however there are plenty of reasons why you may want to re-think running right out to your local aquarium/fish store to purchase one.

 

“I need something to eat all the leftover food”

One of the reasons that you may give for wanting to get these types of fish is that you want something to eat leftover food. In older fish literature, it was stressed that you must provide your aquarium with fish that swim at different levels of the tank but it is unclear if the rational behind this is purely aesthetic or functional. Still today people believe this is the case but when asked why, the answer is usually that they heard they should. Almost always, the reason to get a bottom feeder should be because you are interested in them and think they are attractive, fun creatures who would add an element to your aquarium that was previously missing. We have never once come in contact with a single aquarium that “needed” a bottom feeder and we will tell you why. Fish who dwell near or at the bottom of your tank are in need of the exact level of nutrition as the fish that swim above them. Generally, all too often the thinking is that they have a “job” to do and that they are living in your tank to clean-up the food that the others miss. The problem with this thinking is that it will almost always lead to the fish slowly starving to death. Even if the fish happen to find enough food to keep themselves alive, the immune system of these fish become compromised from insufficient nutrients over time and usually succum to sickness sooner or later. This can be remedied by getting a food that is formulated both to sink to the bottom of the aquarium and one that meets the specific dietary requirements of the species of bottom feeding fish you have in your aquarium.

 

“I need one of those sucker things”

We feel that there cannot possibly be another type of fish more misunderstood than the Plecostomus. Plecostomus encompass a family of “suckermouth” catfish (the Loricariid) that is now over 500 species strong. Still today, most people are only aware of the ones that the big box stores offer or maybe at best, 4 or 5 others. Most stores are selling “the common pleco” (Hypostomus plecostomus). These are usually a very poor choice for the average home aquarium. For one, this species achieves an average adult size of about 24”. For a fish of this size to be at ease with its environment, the aquarium would need to be in excess of 100 gallons. Secondly, people are generally buying one of these fish because they either have an algae problem in their tank or because, like thousands of other well-meaning hobbyists, have been led to believe that their tank “needs” one of these fish without ever understanding why. It is important to buy the correct Plecostomus species for the “job” you want them to perform. If you are interested in buying one for algae control, you will want to choose a species that eats primarily vegetation in the wild. The Bristlenose for example is a type that is mostly vegetarian and will not outgrow tanks over 20 gallons. It’s helpful to realize that the algae growing in your tank is only a single source of nutrients for these fish and even though they may eat it, they are still in need of other sources of vegetation. Algae wafers or other kind of algae based catfish specific food should be offered. This will not keep the fish from eating the algae in your tank, in fact, it may make them eat even more as the fish will be healthier and have a more productive lifestyle within your aquarium. If you are buying a plecostomus for appearances only, be sure to find out what it eats so that you can offer it the correct foods. For example, there are plecostomus that derive nutrients from wood cellulose and therefore would require driftwood or a food that contains the bark of Alder or Willow. Some plecostomus are purely carnivorous and will thrive on a diet of primarily meat based foods like mysis shrimp, krill, bloodworms, and a carnivore sinking pellet/wafer. Still others, eat a combination of all of these foods.


Keeping different plecostomus species is one of our favorite aspects of freshwater fishkeeping. We hope that this simple information will go a long way to helping your plecostomus live a better and happier life within your aquarium. Again, please contact us if you would like to go into greater detail about this topic or any other freshwater aquarium related matter.