Spotted Severum (Heros notatus)

What is a Spotted Severum?

The Spotted Severum (Heros notatus) is a large, oval-bodied South American cichlid native to the blackwater rivers of the Rio Negro and Essequibo basins. It shares the classic severum body plan — deep, laterally compressed, almost disc-like — but is distinguished by rows of dark spots scattered across an olive-yellow base, with faint vertical barring visible under good lighting. Adults are impressive fish, reaching up to 25 cm (10 in) and carrying real presence in a large display tank.

Unlike its more commercially available cousin the Green Severum (Heros efasciatus), the Spotted Severum is a specialist fish. Most specimens in the hobby are wild-caught from blackwater habitats, which means they are accustomed to very soft, warm, acidic water. Replicating those conditions — and sourcing a healthy specimen in the first place — is the main challenge. Keepers who meet that challenge are rewarded with a long-lived, intelligent, personable cichlid that often learns to recognise its owner.

Where do Spotted Severums come from?

The Spotted Severum is native to South America, primarily the Rio Negro — the massive blackwater tributary of the Amazon — and the Essequibo River system in Guyana. Both habitats are classic blackwater environments: dark, tannin-stained water with very low mineral content, very low pH (often below 5.5 in the wild), high temperatures and little current.

This origin directly dictates husbandry. Captive specimens adapt to slightly less extreme conditions, but they do not thrive in the hard, alkaline water that suits Central American cichlids. Serious keepers use RO-filtered water remineralised to a low GH, combined with Indian almond leaves or driftwood to lower pH and add tannins. Almost all trade specimens are wild-caught imports; true captive-bred stock is scarce and worth seeking out from specialist cichlid breeders.

What tank size does a Spotted Severum need?

The minimum tank size is 300 litres (approximately 79 gallons) for a single adult, and larger is strongly preferred for pairs or any community arrangement. At 25 cm (10 in), a fully grown Spotted Severum is a substantial fish that needs genuine swimming space and the ability to establish and defend a territory without constantly coming into conflict with tank-mates.

A long footprint matters more than height — aim for a tank at least 150 cm (60 in) long. The substrate should be fine sand, which allows natural digging behaviour without damaging the fish’s mouth. Large flat stones or broad-leaved bogwood pieces make ideal territorial anchors. Because this species comes from slow, shaded blackwater rivers, aim for moderate lighting and generous planting with hardy species like Anubias, Java fern and Amazon swords. Strong filtration is essential given the bioload of a large cichlid, but keep the current gentle: the Rio Negro is not a fast-flowing river.

What water parameters does a Spotted Severum need?

• Temperature: 26–30 °C (79–86 °F) — at the warmer end of the tropical range.
• pH: 5.5–7.5, but wild-caught fish do best kept below 7.0, ideally 6.0–6.8.
• Hardness: 1–10 dGH — soft water is not optional; hard tap water should be cut with RO.

Stability is critical. A fish adapted to blackwater conditions is particularly vulnerable to sudden chemistry swings. Test water weekly, change 25–30% regularly and use peat filtration or tannin sources (driftwood, Indian almond leaves) to maintain the low mineral, slightly acidic conditions this species is built for. A reliable heater and thermometer are non-negotiable; temperatures dropping below 24 °C (75 °F) stress wild-caught specimens quickly.

What do Spotted Severums eat?

The Spotted Severum is an omnivore with a broad palate. In the wild it grazes on plant matter, algae, invertebrates and opportunistic insect prey. In captivity it accepts most high-quality cichlid pellets or sticks as a staple — choose a formula designed for large herbivore/omnivore cichlids rather than a protein-heavy carnivore diet.

Supplement the staple with blanched vegetables (courgette, peas, cucumber), spirulina-enriched wafers and occasional protein treats such as earthworms or prawn. Feed once or twice daily in amounts the fish finishes in a few minutes. Avoid overfeeding: large cichlids in warm water produce significant waste, and the resulting ammonia spike in soft, low-buffering-capacity blackwater can be damaging fast. Skip one feeding day per week to prevent digestive issues.

How does a Spotted Severum behave, and what are suitable tank-mates?

The Spotted Severum’s temperament is semi-aggressive — more measured than many large cichlids, but still capable of asserting itself strongly, particularly when breeding. A lone specimen or a bonded pair is typically the most manageable arrangement. Two unpaired males in the same tank will compete for territory.

In a large, well-decorated tank with clear territory divisions, the Spotted Severum can coexist with other robust, similarly sized South American species that share its blackwater chemistry needs. Suitable companions include large peaceful tetras (such as bleeding heart or Congo tetras kept in groups), robust Geophagus species, sailfin plecos, and similarly sized South American cichlids with non-aggressive temperaments. Avoid small tetras that may be intimidated or picked off, and Central American cichlids that prefer harder, alkaline water.

For a full, filterable breakdown of compatible species and pairings, see Spotted Severum tank mates.

How do you tell a male Spotted Severum from a female?

Sexual dimorphism in Heros notatus becomes apparent at maturity and is clearest in adult specimens. Males develop distinctive worm-like lines or facial markings on their cheeks and operculum — a pattern of squiggly, iridescent lines that females largely lack or show only faintly. Males are also typically larger and develop a more pronounced nuchal hump on the forehead with age.

Females are generally smaller, have less prominent facial patterning, and tend toward a plainer overall finish. In juvenile fish, sexing is unreliable; meaningful differentiation usually becomes possible from around 10–12 cm (4–5 in) onward, and the differences become most obvious as fish approach full size. Purchasing a small group of juveniles and allowing natural pairing is the most practical approach for breeders.

How do Spotted Severums breed?

Breeding Heros notatus is rated hard and is genuinely demanding. The first hurdle is obtaining a compatible, bonded pair — this typically means raising a small group of juveniles together and allowing pair-formation to occur naturally over time, as forced pairing of adults frequently results in aggression and injury.

Once a pair bonds, they will clean and defend a flat surface — a large slate slab, smooth rock or broad piece of bogwood — and spawn on it, laying several hundred adhesive eggs. Both parents guard the eggs and fry with intensity, which may mean other tank inhabitants need to be removed. The eggs hatch in roughly 2–3 days at 28 °C (82 °F), and the wriggling larvae are often moved by the parents into pits dug in the substrate before becoming free-swimming.

Fry are large enough to accept newly hatched brine shrimp and fine cichlid fry food from the outset. Broodcare continues for several weeks. The soft, warm water conditions this species demands are actually beneficial for breeding success, as harder water can impair egg development. Captive breeding of this species remains unusual, making successful spawning genuinely noteworthy in the hobby.

What diseases are common in Spotted Severums?

Wild-caught Spotted Severums are the more challenging category: they may arrive carrying internal parasites, Hexamita (hole-in-the-head disease) or skin flukes, so a proper quarantine period of at least four weeks in a dedicated tank before introduction to a display is essential.

Hole-in-the-head disease — characterised by pitting erosions on the head and lateral line — is the most commonly reported cichlid health issue and is strongly associated with poor water quality, inadequate diet (particularly vitamin and mineral deficiency) and activated carbon overuse in the filter. Prevention is straightforward: maintain excellent water quality, feed a varied diet rich in vegetable matter, and use carbon sparingly.

Other concerns include ich (white-spot), which presents as white pin-dot speckling and is typically triggered by temperature fluctuation, and bacterial infections at wound sites from territorial disputes. Both are prevented through stable parameters, appropriate tank-mate selection and prompt isolation of any injured or symptomatic fish.

Health note: medication dosing and disease diagnosis are beyond the scope of a care profile. For sick fish, confirm symptoms against a reputable veterinary or fish-health resource before treating, and always quarantine new arrivals before they enter your main display.

How long do Spotted Severums live?

A well-maintained Spotted Severum lives 8–12 years, which is a serious long-term commitment. The fish that reaches its full potential — deep colouration, pronounced facial markings, an established territory and genuine recognition of its keeper — is typically five or more years old. Give it the space, soft water chemistry and varied diet it requires from the outset and this is a species that rewards patience generously.