Pseudacanthicus cf. spinosus “L160”

Order: Siluriformes
Suborder: Loricarioidei
Family: Loricariidae
Subfamily: Hypostominae
Genus: Pseudacanthicus
Species: Pseudacanthicus cf. spinosus, Castelnau, 1855

Pseudacanthicus cf. spinosus "L160" is a large growing pleco, reaching sizes of around 40 cm in total length. The general bodyshape is high and robust built. The whole body is covered with really sharp and pointy spikes. This pleco has a rather large caudal fin.

The overall coloration of this pleco is beige to brown, which also gave him the common name "Coffee and Cream Cactus Pleco". On top of this bright brown coloration dark brown to black spots are visibile on the whole body.

Males can be rather territorial against other members of its genus. In general they seem to be calmer than most other Pseudacanthicus, in our oppinion. This fish mostly sleeps over the day and wakes up for eating. It doesn't show a shy behaviour and is visible most of the day. Sometimes this fish falls asleep sucked on a piece of driftwood or the cave upside down. Then it can happen that the pleco loosens it suction while sleeping and rests laying on its back. This behaviour sometimes looks, like the pleco died, but it is common and when spooked, this fish quickly turns with his belly down again. They are good swimmers and are quite active in the night. A good lid is necessary to prevent spooked animals from jumping out of the aquarium.

P. cf. spinosus "L160" is found in the Rio Tocantins in Brazil. There it shares the same home river with the more colorful Pseudacanthicus pitanga "L24".

This fish is usually caught in deep water of about 20 meters depth. The water there is rich in oxygen and slightly acidic (6 - 6,5 pH). This fish likes it warm, temperatures of up to 30 °C can be measured in its habitat.

Even though this species sometimes takes plant matter its main diet consists of animal proteins. In nature "L160" mostly eats dead fish, crustaceans, worms and insects (larvae).

In captivity this fish can be fed with frozen, live and dried food. Protein rich granules are a good base food for P. cf. spinosus "L160". Additional frozen shrimps, mussels, krill and artemia can be fed.

As previously mentioned, this fish gets huge and therefore needs a lot of space when grown out. Most "L160" in the trade are small enough for normal home aquariums. Since "L160" is a slow grower, it takes several years to reach sizes over 30 cm. Adults shouldn't be kept in tanks under 200 cm length. This fish swims a lot during night, even though it seems a bit inactive over the day.

Very important is a good lid for the aquarium, since Pseudacanthicus spp. push themselfes sometimes far above the water surface. Uncalm behaviour can often be observed when the pleco has gill worms. This leads the fish to jump, swim fast or reach for air outside of the water.

The water should be heated up to 26 - 30 °C and kept neutral to slightly acidic. Good ventilation with a bubblestone and a good filtration are necessary to keep the fish healthy.

Depending on how many other pleco's are in the tank, it should be structered well, to avoid to many territory conflicts. Pseudacanthicus stay calmler in over-crowded tanks, which is only possible when there is a big and efficient filter installled, that can deal with the massive load of bio mass. Meat eaters produce a lot of ammonia, which can be lethal in to high doses.

Structure can be created with different big caves, driftwood and big rocks. Everything should be installed in a way that the "L160" can't toss it over or falls when being digged under. This species digs a lot and enjoys therefore a lot of substrate like sand or gravel.

Light is not necessary. Dimmed light helps to see this shy fish more often over the day.

Unluckily the first try after we got the new fish, our big photo-tank broke while photographing what resulted in a flooded room... the fish was transferred back into its main tank without troubles and stress though.

Our new big foto-tank is finally ready to use and as promised, we could finally make the sex difference post of Pseudacanthicus cf. spinosus "L160".

This robust build pleco makes sexing in general easy, especially if you have to sex adult animals. The bigger the specimens are, the more the secondary sexual traits are visible. But also with this species, thin, young females can be really similar to young males.

The view from the side reveals already quite a lot about the sex of this fish. The male looks higher and bulkier, with a fatter tail and stronger pronounced spikes all over the body.

From the side also the heads show differences. A males head ends in a more round snout with a straight head line, where as females show a slightly convex head line with a pointier end.

Odontodes on the snout itself can be seen with both sexes. Males tend to show them more dominant, but since there is also males with less spikes, its a trait we wouldn't count alone on.

The gills are covered also with odontodes, which are again with the male more dominant.

The hard ray of the pectorals show especially with males a longer and curved shape.

The common name "Spiny monster" gives it away, referring to the really sharp odontodes on the sides of the body. Both male and female show them. Males tend to have them till behind the head, where as females show them mostly in the hind body part. Females show them less dominant than males.

Sometimes sexing from top is the easiest with Pseudacanthicus spp..
If you compare both specimens, you can see, that the male has a huge head compared to the body and also keeps his thick body shape till the tail. Females are broadest between the pectoral and pelvic fins. The head is smaller and the tail region looks thinner.

The heads can sometimes look relatively similar in young age with both sexes. The male tends to have a rounder snout with more odontodes on it. The eyes sit further apart with males, and give a little bit more the impression of a "frog-face". Females look smoother around the borders of the head, which ends in a more pointy snout.

To judge the sex only by the papilla shape itself is rather hard with this species, since it changes shape and size with contracting movements. In this case the male seems to have even a rounder and bigger papilla, which is with most other plecos a feminine trait. Also this female shows yellow dots around the papilla, which we could also observe and photograph with females of other pleco species.

Pseudacanthicus cf. spinosus "L160" is a cave breeder, where the male takes care of the eggs and larvae till they hatch and use up their yolk sac.

Captive breeding has been successfully accomplished by several breeders on several occasions. Good water quality and a harmonizing breeding pair is necessary for success. Other than that we have not much more information, how to breed this pleco.

We will soon write a breeding report on breeding this species.