Freshwater plecos, also known as plecostomus or simply "plecos," are a popular type of aquarium fish known for their ability to help keep tanks clean. They belong to the family Loricariidae and come in a variety of species, shapes, and sizes. They are often sought after for their unique patterns and their ability to eat algae, uneaten food, and other debris that may accumulate in the aquarium. Plecos can grow to be quite large, with some species reaching up to 2 feet in length, though there are smaller species available as well. They are generally peaceful, but may become territorial as they get larger, so it is important to make sure they have plenty of hiding places and space to swim. Plecos are known to be hardy and easy to care for, making them a popular choice for beginner and experienced aquarists alike.