Malawi eye-biter - Dimidiochromis compressiceps

Scientific name: Dimidiochromis compressiceps

Common name: Malawi eye-biter

Family: Cichlidae

Usual size in fish tanks: 15 - 25 cm (5.91 - 9.84 inch)

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Recommended pH range: 7.8 - 8.6

Recommended water hardness: 9 - 19°N (160.71 - 339.29ppm)

0°C 32°F30°C 86°F

Recommended temperature range: 24 - 27 °C (75.2 - 80.6°F)

The way how these fish reproduce: Spawning

Where the species comes from: Africa

Temperament to its own species: peaceful to females

Temperament toward other fish species: aggressive to smaller

Usual place in the tank: Top levels

Short description

Dimidiochromis compressiceps is a streamlined, laterally-compressed haplochromine predator from Lake Malawi, famous for its ambush behavior among Vallisneria beds and its tendency to target the eyes of similarly sized rivals—hence the common name “eye-biter.” In the aquarium it is fast, powerful, and highly visual; provide ample open swimming space and a long tank footprint. Avoid housing with small tankmates—it will treat them as food.

Minimum tank size & aquascape

• Minimum tank (single adult male with females): 500 L (≥150 cm length). For mixed hap setups, 600–700 L with ≥180 cm length is strongly recommended.
• Layout: Sandy substrate with large open areas for sprinting; a few rock piles for line-of-sight breaks; optional tall, strap-like plants (e.g., Vallisneria) to emulate hunting cover.
• Flow & oxygenation: Moderate flow, strong aeration/filtration. Keep water ultra-clean to prevent bloat and gill issues.

Water parameters

Maintain stable alkaline conditions typical of Lake Malawi: pH 7.8–8.6 and hardness around 9–19 °dGH. Temperature 24–27 °C (75–81 °F). Prioritize stability over “chasing numbers.” Perform regular, substantial water changes (30–50 % weekly) to control nitrate.

Diet (Food & feeding)

A strict piscivore in nature; in aquaria accept high-quality carnivore/hap pellets, krill, mysis, chopped prawn/shrimp, mussel, and small portions of white-fish fillet. Feed modest portions 1–2× denne to avoid obesity and fatty liver. Avoid: feeder fish (disease risk, encourages hyper-predation), mammalian meat (beef heart), and excessively fatty seafood. Rotate foods to ensure complete nutrition.

Behavior & compatibility

• Intraspecific: Males are territorial, especially in breeding color. Keep one male with a small harem (2–3 females) in large tanks.
• Interspecific: Predatory; will harass or eat smaller fish. Mix only with similarly sized, robust Lake Malawi haps/utaka that occupy different niches.
• Aquascape tips: Long sightlines reduce panic sprints; add rock “islands” to break aggression loops.

Recommended tank mates (Malawi hap/utaka, similar size ±20%)

• Cyrtocara moorii (20–25 cm) – peaceful sand sifter; different feeding niche.
• Copadichromis borleyi (15–20 cm) – utaka; midwater planktivore (borderline smaller → needs size parity).
• Protomelas taeniolatus (15–20 cm) – robust but not hyper-aggressive.
• Sciaenochromis fryeri (15–20 cm) – assertive; mix only in large tanks with careful ratio.
• Nimbochromis venustus (up to ~25–30 cm) – works in very large systems; monitor dominance.

Avoid: Mbuna and any small or slender species; ornamental livebearers; juveniles of larger species.

Sexing

Males develop intense metallic blues/greens with extended fins and often orange to red edging in the dorsal/anal fins; females and juveniles are silvery with a dark lateral stripe and subtler patterning. Adult males are noticeably larger and more imposing.

Breeding

• Mode: Maternal mouthbrooder (spawning on open sand or shallow pits near vegetation).
• Clutch & incubation: ~20–60 eggs; incubation ~21–28 days at ~26 °C. Female stops feeding while holding.
• Rearing: Fry are sizable and predatory early; offer newly freed fry with enriched brine shrimp, finely chopped mysis/krill, and quality crumble.
• Note: Provide visual cover and low stress; strip holding females only if necessary and experienced.

Plants (from the same region / biotope-friendly)

Lake Malawi shorelines can feature tall stands of Vallisneria, which this species uses for ambush cover. In aquaria, hardy Vallisneria spp. are the most authentic choice. Ceratophyllum demersum (hornwort) is cosmopolitan and may also be used, but most Malawi displays remain sparsely planted due to cichlid behavior and hard, alkaline water.

Care level

Intermediate to advanced: requires large, well-filtered tanks, disciplined stocking, and predator-appropriate feeding. Rewarding centerpiece hap when kept with suitable tankmates and space.

Picture

Thanks to Marwin! Other pictures were bought from jjphoto.dk.