Heros severus Severum

Heros severus is the 'true' severum species from the Orinoco basin and Venezuelan river systems, distinguishable from the Amazon-distributed H. efasciatus by subtle morphological features including differences in scale counts, facial marking complexity, and bar number. Wild males develop intricate blue-green vermiculate (worm-like) patterns on the face and throat that intensify during breeding condition.

H. severus inhabits slow-moving blackwater and clearwater rivers, floodplain lakes, and flooded forest margins in Venezuela and adjacent Colombia. It adapts reasonably well to aquarium conditions, though it benefits from soft, slightly acidic water that more closely mirrors its Orinoco homeland.

This species is less frequently imported than H. efasciatus but is considered by enthusiasts to display superior facial markings and colouration in prime condition. It is fully suitable for the intermediate aquarist with an appropriately large aquarium.