Care
Native to the warm, oxygen rich flowing waters of the Rio Tapajos, where rocks provide the caves and crevices they call home.
The aquarium should be mature, with a soft sand substrate and various pieces of smooth rockwork and driftwood arranged to create lots of small nooks and crannies. There should be brisk water movement and a high level of oxygenation, perhaps provided by a river-tank manifold or powerheads (in addition to the current generated by the filtration). As plants are not found in any great abundance in the natural habitat, they can be omitted from the aquascape, although a few areas of hardy vegetation (that can cope with current) will make the aquarium look more aesthetically pleasing and will help with water quality. Ample hiding places/visual barriers amongst the decor will enable you to keep a group of these fish together and will obviously further your chances of breeding them. Male Hypancistrus are fairly territorial and care should be taken to provide plenty of caves. Tankmates must be small and peaceful, and able to thrive in warm, fast-flowing water. As these fish do not compete well for food, avoid keeping with fish that are boisterous at feeding times. These plecs are largely carnivorous and will not make any impact on algae. Ensure that regular partial water changes are carried out as these catfish will not tolerate an elevated nitrate level.
Feeding
Offer a variety of meaty foodstuffs such as bloodworm, white mosquito larvae, Mysis shrimp, chopped prawns, and various sinking pellets designed for carnivores. Vegetables such as slices of cucumber may be nibbled at but are not usually taken with any real enthusiasm.
Breeding
This species has been bred in the home aquarium and makes for a very worthwhile breeding project. The temperature of the water should be raised to 28 °C and it must be extremely well-filtered and highly oxygenated. Provide a selection of small caves which have an entrance only marginally bigger than the fish. These can either be formed from arranging the rockwork in such a way that small, secluded crevices are created, or pre-constructed from small pieces of slate siliconed together. It is crucial that these caves are situated in an area with decent water movement. When in spawning condition, males will choose a preferred cave and defend it from any other males present, whilst at the same time, will try to entice a ripe female inside. Spawning does not always take place straight away; indeed, it can be some days before the female is ready to deposit her eggs, but the fish will remain inside the cave together during this time, the male usually blocks the entrance. Once the eggs have been laid and fertilised, the male fish often has to force the female out of the cave before he begins his parental guarding duties. The female plays no further part in brood care, but the male will be seen fanning the eggs with his pectoral fins and blocking the cave entrance from any intruders. Eggs typically number around 45 and take around a week to hatch. The fry will feed from their sizeable yolk sacs for the first few days, and after this has been consumed, they will require very regular feedings of baby brineshrimp (Artemia nauplii), microworms, and various small or crushed dried sinking foods. It is important that food is available to the fry at all times as they can all too easily starve but keep a very close eye on water quality when feeding constantly and perform lots of very regular but very small partial changes to keep nitrogenous waste levels as low as possible. The adults pose no threat to the fry, but other fish sharing the same tank might do. This is why many aquarists like to keep these catfish in a species-only set up, to further their chances of raising the maximum number of young.
