Acanthicus hystrix, known scientifically as Acanthicus hystrix, belongs to the family Loricariidae, or Armored Catfishes. Due to its size and certain behavioral characteristics, this fish is not suitable for beginner aquarists. It is usually found in very large private or public aquariums. It is worth noting that young individuals are quite often offered for sale, but as they grow, they can create significant difficulties in care.

Tank
from 1000 L (264 gal)
Temperature
23 – 30 °C (73 – 86 °F)
Size in aquarium
50 – 60 cm (20 – 24 in)
Acidity
pH 6–7.5
Natural rangeRange on the map
  • Amazon River
  • Amazon Basin
  • Brazil
  • Peru

Tank conditions

Plan the tank stocking
Temperature
23 – 30 °C (73 – 86 °F)
Water pH
Slightly acidic (6) – Neutral (7.5)
Water dH
Very soft (2) – Hard (15)
Water salinity
no salt (freshwater)
Size in aquarium
50 – 60 cm (20 – 24 in)
Lifespan
16 years
Temperament
Aggressive Aggressive / incompatible / unfriendly
Toward small fish
not a predator
Required aquarium volume
from 1000 L (264 gal)
Lighting
dimmed
Substrate
any (no restrictions)
Water flow
weak or moderate
Feeding
Any (universal)
Keeping
Solitary
  • Lifespan. A lifespan to expect under good care, not a measured value: it depends heavily on tank volume, water quality and diet — and for selectively bred forms, on their origin as well.
  • Toward small fish. Based on the Predators category in the catalog or the temperament in the species parameters. “A risk to small fish” means the species is not a predator by habit, yet will swallow any fish that fits in its mouth.
  • Required aquarium volume. This is a husbandry recommendation, not a measured value: the volume depends on the keeping mode (solitary), footprint, decor and tank mates.

Care and keeping

Description

Adults of this fish can reach a length of 50 to 60 centimeters. They have an impressive body, a large head, and powerful fins, the first rays of which are significantly thickened and resemble spines. The entire body surface is covered with numerous sharp thorns. These protective elements serve to defend the catfish from the many predators inhabiting the Amazon. Their coloration is black. Sexual dimorphism is weakly expressed, and it is quite difficult to visually distinguish males from females.

Habitat

This species of catfish originates from South America. Precise data on its distribution range are not always specific, and literature traditionally indicates "Amazon River" as the type locality. However Acanthicus hystrix is widely distributed throughout the Amazon, covering territories in Brazil and Peru, and also encompassing large river systems, such as the Orinoco in Venezuela. The fish prefers sections of rivers with slow currents. Its presence is often noted near settlements located along riverbanks. This phenomenon is likely explained by the availability of food waste that local residents discharge directly into the water.

Behavior and Compatibility

Young catfish exhibit a peaceful nature and often form groups. However, as they mature, their behavior changes: Acanthicus become increasingly aggressive and territorial, which dictates the need to keep them individually. They are compatible only with other large fish that prefer to inhabit the water column or near its surface.

Care and Maintenance

For keeping an adult specimen, an aquarium of at least 1000 liters will be required. Acanthicus hystrix feels comfortable in subdued lighting and needs a large number of suitable-sized shelters. Caves and grottoes can be created from driftwood, rock fragments, large stones, as well as decorative elements or ordinary PVC pipes. The presence of live aquatic plants in the aquarium is not mandatory, as they will most likely be uprooted and eaten. Maintaining high water quality is ensured by using a powerful filtration system and regular aquarium maintenance. It is also extremely important to maintain a high level of dissolved oxygen, so additional aeration will be very useful.

Diet

This is an omnivorous and rather voracious species. It actively explores the bottom of the aquarium in search of food, eating everything it can find. Their diet can include a wide range of diverse products: dry sinking foods, live or frozen bloodworms, earthworms, chopped pieces of shrimp or mussel meat, as well as various vegetables and fruits. Feeding should be daily. Signs of underfeeding, which are easy to notice, include a sunken belly and hollow eyes.

Breeding and Reproduction

This species does not breed in artificial environments. In the natural environment, spawning occurs during the rainy season, in caves that the fish digs in the steep banks of rivers. After spawning, the male drives away the female and remains with the clutch, protecting it until the fry hatch.

Diseases

Most health problems in fish often arise from unsuitable keeping conditions. Maintaining a stable and comfortable habitat is a key factor for successful keeping. If symptoms of illness appear, the first step is to check the water quality. If deviations are found, it is important to take immediate measures to eliminate them. If the symptoms do not disappear or worsen, medicinal treatment may be required.

How to choose

When choosing Acanthicus hystrix, it should be noted that young individuals are most often available for sale, which will eventually grow to impressive sizes and require aquariums of 1000 liters or more. When inspecting fish in the store, pay attention to the following signs of health: activity, absence of skin and fin damage, and clear eyes. A healthy individual should not have a sunken belly, which is a clear sign of emaciation. Keep in mind that this species has strong territorial instincts, so purchasing multiple individuals for one aquarium carries a high risk of aggression as they mature.

Compatibility

There are no pair reviews for this species yet — check tankmates in the matcher.

All tankmates

Plants and this fish

Matching water does not mean the plant will stay intact.

Frequently asked questions

The essentials: size, tank volume, water parameters and care

How big does Acanthicus hystrix get?

An adult reaches 50–60 cm in length. Plan the tank around the maximum size: the fish quickly outgrows a cramped setup.

What size aquarium does Acanthicus hystrix need?

The recommended volume is 1000 L. A smaller tank speeds up nitrate build-up and raises stress levels.

What water parameters does Acanthicus hystrix need?

Temperature 23–30 °C, pH 6–7.5, hardness 2–15 dGH. Stability matters more than exact values: sudden swings are harder on the fish than a small deviation from the ideal.

How long does Acanthicus hystrix live?

Around 16 years when kept properly. Lifespan depends directly on tank volume, water quality and a varied diet.

Is Acanthicus hystrix aggressive?

Temperament: aggressive / incompatible / unfriendly. Keep this in mind when choosing tank mates.

How many Acanthicus hystrix should be kept together?

Recommended setup: solitary. Ignoring this is a common cause of stress and disease.

What does Acanthicus hystrix eat?

Diet type: any (universal). Feed small portions that are finished within a couple of minutes — overfeeding does more harm than underfeeding.

What is the scientific name of Acanthicus hystrix?

The scientific name of the species is Acanthicus hystrix, family Armored Catfishes (Loricariidae). It also appears in the literature as: Rinelepis acanthicus.

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Other scientific names and conservation status

Other scientific names
Rinelepis acanthicus
Categories
Catfish, Giants
Conservation status
Least concernLC