Araguaia Cory 'Rio Araguaia' (Hoplisoma araguaiaense)

Common Name

Araguaia Cory

Scientific name

Hoplisoma araguaiaense

Origin and Habitat

Native to central Brazil in the Araguaia River basin. Collections come from the Rio Araguaia and connected streams such as the Rio das Mortes. These are clear, warm, well oxygenated side channels with pale sand, scattered pebbles, leaf litter, and tangled roots. The fish sift gently through the sand along shaded margins under overhanging vegetation where fine food collects.

Temperature and Water Conditions

Preferred range is 72 to 79 F, which is 22 to 26 C. Basin water is commonly near neutral, roughly 6.0 to 8.0 depending on site, with soft to moderately hard readings. We do not recommend chasing numbers for routine care. Stable, clean, oxygen rich water is far more important. Keep ammonia and nitrite at zero and nitrate very low with regular partial changes and gentle flow.

Appearance and Size

A petite Cory with a creamy to light tan body sprinkled with neat dark spots. The caudal fin often shows tidy transverse bars that read well against a pale sand bed. Adults stay tiny, about 3.5 cm standard length, roughly 1.4 inches. Males are slimmer, females grow rounder when in condition. The compact size and crisp spotting make a larger group look like living confetti gliding across the substrate.

Diet in the Wild

Micro predator and detritus sifter. It roots through sand and leaf litter for insect larvae, tiny worms, micro crustaceans, and edible biofilm.

Feeding in Captivity

Match the small mouth with fine foods. Offer high quality sinking micro pellets, crushed wafers, and fine granules. Add baby brine shrimp, daphnia, cyclops, and finely chopped bloodworm for conditioning. Scatter food widely so the whole school can graze together. A soft sand bed protects barbels and lets them feed naturally.

Behavior and Tank Setup

Peaceful, social, and much more confident in a proper school. A dozen or more brings out synchronized foraging and playful sifts. Use a long footprint tank with fine sand, pockets of leaf litter, and root or branch cover. Provide gentle to moderate flow with high oxygen and subdued light. Ideal companions include small calm characins and other peaceful fish that enjoy clear, clean water.

Breeding

Classic Corydoras T position spawning with adhesive eggs. Condition adults on quality live and frozen foods, then use a series of larger cool water changes to mimic seasonal cues. Offer spawning mops, fine leaved plants, and smooth vertical surfaces like glass or tiles. Adults will eat eggs, so either remove the parents after a spawn or move the eggs to a small hatching container with gentle aeration. Eggs typically hatch in three to five days depending on temperature. Start fry on paramecium or a suitable liquid fry food for the first days, then transition to microworms and newly hatched brine shrimp. Keep water very clean and shallow at first, with sponge filtration and frequent small changes.

Quick Facts

• Scientific name: Hoplisoma araguaiaense
• Origin: Araguaia River basin in Brazil, including the Rio Araguaia and connected streams
• Adult size: about 3.5 cm standard length, roughly 1.4 inches
• Temperature: 72 to 79 F (22 to 26 C)
• Wild pH: about 6.0 to 8.0 depending on site, soft to moderately hard water
• Temperament: peaceful schooling catfish, keep in groups
• Diet: micro predator and substrate sifter, accepts fine prepared and frozen foods
• Breeding: adhesive egg layer, T position spawner, responds to cool water changes

Tropical Fish Co. Notes

Tiny size, tidy spots, and a graceful sand sifting rhythm make this species a star in thoughtfully kept community tanks. We like to showcase them on pale sand with dappled shade, a look that echoes quiet margins of the Araguaia. Give them steady, clean water and a big enough school to feel safe, and they reward you with nonstop synchronized charm.