Tigrinus Catfish

Also known as: Merodontotus tigrinus

The Tigrinus Catfish (Merodontotus tigrinus) is a large, strikingly patterned nocturnal predator native to the Amazon’s blackwater systems. The Tigrinus Catfish originates from Amazon River basin in Brazil, Peru, and Colombia, inhabiting slow-moving, tannin-stained blackwater streams and flooded forests with sandy substrates and submerged woody debris., reaches Adult size: 45-55 cm in captivity, typically lives 12-18 years, and is kept at 24-28°C (75-82°F). Individual fish vary, so treat this as a general guide rather than a guarantee.

Species at a glance

Origin: Amazon River basin in Brazil, Peru, and Colombia, inhabiting slow-moving, tannin-stained blackwater streams and flooded forests with sandy substrates and submerged woody debris.
Adult size: Adult size: 45-55 cm (18-22 inches)
Life span: 12-18 years
Temperament: Solitary and territorial; generally peaceful toward similarly sized non-aggressive tankmates but may prey on small fish and exhibit aggression toward conspecifics in confined spaces.
Tank size: Minimum 300 liters (80 gallons) for a single adult; 450+ liters (120+ gallons) recommended for long-term health and natural behavior expression.
Water temp: 24-28°C (75-82°F)
pH range: 5.0-7.0
Diet: Carnivorous; feeds on live and frozen foods such as earthworms, bloodworms, brine shrimp, small fish, and crustaceans; accepts high-protein sinking pellets but requires varied diet to prevent nutritional deficiencies.
Other names: Merodontotus tigrinus

About the Tigrinus Catfish

The Tigrinus Catfish (Merodontotus tigrinus) is a large, strikingly patterned nocturnal predator native to the Amazon’s blackwater systems. Its body is covered in bold, vertical black and yellow tiger-like stripes that provide camouflage among submerged roots and leaf litter. Adults develop a robust, elongated body with a broad head and prominent barbels used to detect prey in low visibility. Though slow-moving, it is an ambush hunter capable of rapid strikes when prey is detected.

Lifespan and health

With optimal care, Tigrinus Catfish commonly live 12-18 years, with exceptional specimens reaching 20+ years in large, well-maintained systems; growth is slow, averaging 2-3 cm per year after the first two years, and sexual maturity is not reached until 3-4 years of age, making long-term commitment essential. Common health issues include bacterial infections (especially Aeromonas and Pseudomonas) from poor water quality, manifesting as fin rot or ulcers—treat with antibiotic baths and improve filtration; parasitic infestations like Ichthyophthirius multifiliis (Ich) are rare but possible in new arrivals, requiring copper-free treatments due to sensitivity; lateral line erosion and obesity are frequent in captivity from overfeeding or inadequate diet, preventable by maintaining strict feeding schedules and providing live food enrichment.

Overview

Care and tank setup

Tank setup should prioritize a soft, fine sand substrate (minimum 5 cm depth) to allow natural burrowing behavior, supplemented with driftwood, rock caves, and dense planting of hardy species like Anubias or Java Fern to mimic blackwater conditions; lighting should be dim, using LED strips with red/blue spectrum to simulate twilight, as bright light causes stress. Water parameters must be maintained with excellent filtration (turnover rate 4x tank volume per hour) using canister or sump systems, weekly 25% water changes with dechlorinated, soft water (GH 3-8 dGH, KH 1-4 dKH), and addition of peat extract or Indian almond leaves to maintain tannins and lower pH naturally; avoid strong currents as this species prefers calm zones. Feeding should occur 2-3 times weekly in the evening, offering meaty foods equivalent to 2-3% of body weight per meal, with uneaten food removed within 2 hours to prevent ammonia spikes; never rely solely on dry pellets as this leads to malnutrition and lateral line erosion.

Adding a Tigrinus Catfish? Research the species’ adult size and temperament carefully, quarantine new fish before introducing them to your tank, and buy from reputable aquarium stores or breeders.

Breed information on this page is based on the Wikipedia article on the Tigrinus Catfish, supplemented with additional research. Reviewed for accuracy.