The scientific name is Hypostomus plecostemus and every aquarium has one. I’ve always known it as the janitor fish because it eats the dirt in the aquarium and keeps the interior of the glass clean. There is an article in the Department of Science and Technology website however that says the fish has been misclassified. There are actually two species of the janitor fish, the “Pterygoplichthys pardalis found in the Marikina River and Lake Paitan in Cuyapo, Nueva Ecija; and the Pterygoplichthys disjunctivus found in Laguna de Bay.” The same article says that contrary to claims that the fish is inedible, according to Dr. Jonathan Armbruster, curator of fishes at Auburn University, South Americans “usually gut and grill them whole or make soup with them.”
We used to keep an aquarium, we had several actually in various sizes, and we always had a janitor fish. Years ago, when we were living in the city, we moved from my family home to my grandmother’s house next door. At the time, Alex had a five-gallon aquarium in the bedroom. Because we didn’t know where to put the small aquarium in my grandmother’s house, we convinced her to leave it behind and we would just keep the 20-gallon aquarium.
So, we left it there. I didn’t even have time to clean it out. I just transferred the gold fish to the bigger aquarium, turned off the water filter and left the thing half filled with water. I didn’t know that a janitor fish got left behind.
Months later, my brother and his family moved into the house we vacated. They have sons and the oldest, a year or so younger than Alex, wanted to revive the aquarium. My sister-in-law asked if he could have it, Alex did not object and so my sister-in-law started the process of cleaning it out. One afternoon, she came over to tell me a most amazing story.
She was removing the murky green water from the aquarium when something jumped and she screamed. It was a large janitor fish very much alive months after we left the small aquarium in the kids’ bedroom. It had a gaping hole in its body but it wasn’t sickly. We transferred it to the 20-gallon aquarium, the wound healed and, well, it lived longer than any of the gold fish. That is how resilient the janitor fish is.
So, when you hear stories about how they are taking over Marikina River and Laguna de Bay and how hard it is to get rid of them, well, just think how that janitor fish survived. The janitor fish multiply so fast that, combined with their amazing ability for survival, and you have people complaining about how they are fast infesting our lakes. In a forum called Scientist Solutions, someone described the scenario this way: “If you throw a fishing net in one of our affected lakes, you can get a boatful (dinghy size) in about 5 minutes.”
Despite the assurance of that Auburn University fish curator that the janitor fish is edible, they have not found their way into our cuisine. However, some enterprising people have found some good use for them — as biofuel, the fish bones as water purifier, and fish skin as accent for footwear. The lowly janitor fish comes of age.