Plecostomus

1 Species Overview

The Plecostomus (also called the sucker fish, garbage fish, or pipa fish) reproduces readily in rivers. In the aquarium it clings to the glass or plants and licks algae, which is why it is the classic ‘tank cleaner.’ Because it is an invasive species in China with no natural predators, it threatens native fish.

Its Chinese name is Qing Dao Fu. It is a catfish (family Loricariidae), gray-black with black-and-white markings. Its aliases are sucker fish, garbage fish, and pipa fish; it eats other fish’s eggs and algae.

2 Morphological Characteristics

Many keepers add one or more plecos to clean the tank, but its role is not as magical as thought — it also eats prepared food and will attack other fish.

The body is semi-cylindrical and laterally flattened, with a shallowly forked tail fin and an inferior mouth. The dorsal fin is large, the belly flat, and the left and right pelvic fins join into a round, fan-shaped sucker. Seen from below it looks like a small pipa (a Chinese lute), giving the name ‘pipa fish.’ The body is dark brown covered with black spots and reaches up to 250 mm.

A healthy pleco has intact skin, is gray-black or light brown with black-and-white markings, and has a flat belly with pelvic fins forming a sucker. Buy from a reputable, trusted aquarium shop, and watch whether the fish clings to the glass or plants eating algae — that habit is a good sign of health.

3 Habitat & Living Environment

People call it the garbage fish, but keeping it is not as simple as giving it water and walking away. Its water demands are low, but not zero.

The pleco is a scaleless fish, so it is very sensitive to salt and medications — keep the water clean and free of these residues. The best water is neutral to weakly acidic and soft. As a tropical fish it needs warmth; the ideal temperature is above 20°C. It can survive around 20°C, but its condition declines.

It is not a small fish, so use a tank at least 50 cm long. Being omnivorous, feed it a varied diet.

4 Feeding Guidelines

The pleco is affectionately called the garbage fish, but that does not mean it diligently eats only tank waste. It is omnivorous and loves bloodworms and meat paste; when feeding it, keep a few points in mind.

Do not keep a pleco with discus or small fish. It will attack other fish — especially discus, clinging to their bodies and nibbling their scales. It is predatory and steals food from small fish; the feed you add may be monopolized because the small fish cannot compete. Its appetite is large, and if you overfeed, far from clarifying the water it will leave piles of feces that spoil the look of the tank.