“Severum” is a trade name for a deep-bodied South American cichlid. The older name Cichlasoma severum is treated as a synonym of Heros severus in current taxonomic records. The name on a sales label does not by itself establish that every color form offered is that exact species. Confirm the fish’s identification with the retailer before applying species-specific water and adult-size figures.
Adult size and space
FishBase records Heros severus at up to 20 cm standard length, before the tail fin. Plan housing around an adult of that scale, including turning room, filtration capacity and space for companions to avoid one another. A gallon figure alone cannot describe whether a particular tank has enough footprint. Discuss the intended fish and full stocking plan with an aquatic retailer before purchase.
Water, feeding and companions
Use a mature, filtered freshwater aquarium and test water quality on a routine schedule. FishBase records H. severus from South American river basins, with warm, soft, acidic wild-water values; captive-bred trade fish and other Heros species may not have identical requirements. Avoid abrupt parameter changes and match the plan to the identified fish. Provide a varied diet suited to the fish offered and remove uneaten food so it does not degrade the water.
OATA notes that some calmer American cichlids, including severums, can live in a robust community with larger shoaling fish, but compatibility is not guaranteed. Size, individual behavior and breeding territory matter. Provide cover and visual breaks, observe interactions and be prepared to separate fish if the arrangement does not work. Do not use the “false discus” nickname as a care guide for true Discus.
Sources: Eschmeyer’s Catalog of Fishes for the accepted Heros severus name; FishBase species record for size and habitat; OATA American cichlid care sheet for general aquarium and compatibility guidance.