Heros Severus True Severum Care Guide

Most “severums” sold in Singapore aquarium shops are actually Heros efasciatus, the substrate-spawning green severum. The genuine Heros severus is a maternal mouthbrooder, smaller in adult size and significantly less common in the trade. Authentic heros severus true severum care is straightforward once you understand the species’ soft-water blackwater origin and its quirky breeding behaviour. This guide from Gensou Aquascaping at 5 Everton Park sorts out identification, tank planning and the best ways to find legitimate stock locally.

Telling True Severus From Efasciatus

True Heros severus reaches only 18 to 20 cm versus efasciatus at 25 cm. The severus body is more compressed laterally, the dorsal silhouette less domed and the vertical bars on the flanks remain visible into adulthood whereas efasciatus often loses them. The clincher is breeding behaviour: severus broods eggs in the female’s mouth, while efasciatus pairs spawn on a flat surface. If your “severum” pair guarded eggs on a rock, it is efasciatus.

Origin and Natural Habitat

Severus inhabits the upper Rio Negro and Orinoco basins in true blackwater conditions: pH 4.5 to 5.8, near zero conductivity, dark tannin-stained water under flooded forest canopy. Adapting captive stock to Singapore PUB tap requires gradual acclimatisation; never throw a wild import directly into hard tap water. F1 and F2 farm-bred severus tolerate up to pH 7.0 and gH 6 without obvious stress, but breeding rarely succeeds outside soft acidic conditions.

Tank Size for a Pair or Group

A bonded pair needs 90 cm of length minimum, with 120 cm preferred. A group of six juveniles raised to allow natural pair formation needs 150 cm and 60 cm depth. Severus are less destructive than oscars or efasciatus but still uproot rooted plants. For Singapore HDB setups, a 4-foot 240 litre tank holds a pair comfortably for life, while a planted scape needs 5-foot or larger to keep replanting frustration manageable.

Water Chemistry From PUB Tap

Target pH 5.5 to 6.5, kH 0 to 3 dKH, gH 1 to 5, and 27 to 29°C. PUB tap at pH 7.5 cannot reach those numbers without RO blending or substantial driftwood and peat acidification. A 50:50 RO and tap blend, run through driftwood and Indian almond leaves, drops pH to around 6.2 reliably. Nitrate must stay under 15 ppm; severus are unusually sensitive to organic build-up. The peat moss aquarium softening water naturally piece covers natural acidification methods.

Hardscape and Planting

Severus thrives in a flooded-forest layout: tangled driftwood roots, scattered leaf litter on a fine sand bed, and tall background plants like Echinodorus bleheri that give visual depth without crowding the swimming column. Use floating plants such as Amazon frogbit to dim overhead light; severus shy away from bright displays. Catappa, oak and beech leaves layered on the substrate create the tannin-stained look the species shows best in. Reference our flooded forest biotope aquascape piece for the full layout approach.

Diet and Feeding

Severus are largely herbivorous in nature, eating fruit, seeds and plant matter washed in during floods. Feed a vegetable-heavy diet: blanched courgette, deshelled peas, Repashy Soilent Green and quality plant-based pellets. Supplement twice weekly with frozen bloodworm or mysis. Heavy meat diets cause bloat and colour fade in this species. Two modest feeds daily produce better long-term health than one heavy feed.

Tank Mate Selection

Severus are peaceful for their size and pair well with cardinal tetras in shoals of 30 plus, hatchetfish, dwarf cichlids like Apistogramma agassizii, and corydoras for the substrate clean-up. Avoid fast aggressive tank mates that snatch food, large cichlids, and any African species. Discus and severus share a wishlist of water parameters and coexist gracefully in a 5-foot tank.

Mouthbrooding Behaviour

The female lays 80 to 200 eggs on a cleaned flat stone, then takes them into her mouth within hours of fertilisation. She broods for 14 to 16 days without feeding, releasing free-swimming fry that continue to dart back into her mouth for safety for another fortnight. The male defends territory but does not assist directly. Spawning triggers include a 20% cool soft water change and a slight temperature drop to 26°C.

Singapore Sourcing

True severus is rare in Singapore. C328 and Iwarna occasionally import F1 stock at $80 to $150 per juvenile. Aquatic Avenue and specialist Carousell sellers sometimes have wild Rio Negro adults at $300 plus. Always confirm the species before paying severus prices; ask for video of breeding behaviour or measure adult dimensions. Most shops mislabel efasciatus as severus, and the price difference matters.

Common Health Issues

Wild severus often arrive with internal parasites; treat prophylactically with metronidazole and praziquantel during a three-week quarantine. Hexamita appears in nitrate-heavy tanks as white stringy faeces and head pitting. Ich is uncommon at the natural temperatures severus prefer. Skin slime fungus appears in tanks with water above pH 7.5; correct chemistry and the issue resolves on its own.

Long-Term Outlook

True severus lives 12 to 15 years in stable soft-water conditions, longer than efasciatus on average. A chiller holding 27 to 28°C is the difference between a healthy decade-long display and a tank that gradually loses fish to creeping organics during Singapore’s monsoon humidity peaks. The chiller sizing singapore climate guide covers sizing for tanks above 200 litres.

Related Reading

• Severum Cichlid Care Guide
• Red Spotted Severum Care Guide
• Amazon Biotope Aquarium
• Flooded Forest Biotope Aquascape
• Uaru Cichlid Care Guide