Wolterstorff's Pearl Fish (Cynolebias wolterstorffi) — 4-6cm

Overview

The Wolterstorff's Pearl Fish (Cynolebias wolterstorffi) is a rare, beautifully patterned seasonal killifish native to seasonal freshwater pools and wetlands of northeastern Brazil. Reaching 4cm in length, this peaceful species is prized for its unique behaviour and striking colouration. As an annual killifish adapted to temporary habitats that dry seasonally, Cynolebias wolterstorffi has a compressed life cycle and unique reproductive biology. Available for sale UK from Tropical Fish Co, this rare species rewards experienced keepers with captivating displays and fascinating breeding behaviour in species-only aquariums.

Appearance and Coloration

Wolterstorff's Pearl Fish displays stunning colouration with a compact, robust body adorned in intricate patterns of blue, green, red, and yellow with pearl-like iridescent spots scattered across the scales. Males are intensely coloured with pronounced finnage and a bold presence, especially during courtship. The fins feature delicate patterning and iridescent highlights that shimmer under subdued lighting. Females are smaller, plumper, and more subdued in colour with shorter finnage. In a planted tank with dark substrate, the colours and pearly spots become even more vibrant and eye-catching.

Natural Habitat

Cynolebias wolterstorffi inhabits seasonal freshwater pools and wetlands of northeastern Brazil. These temporary water bodies fill with water during the wet season and dry completely during the dry season. The water is typically soft, slightly acidic to neutral, and well-vegetated, with a substrate of mud and organic debris. During the wet season, adults spawn rapidly; as pools dry, adults perish while eggs remain dormant in dried substrate, hatching when rains return months later. This annual life cycle is fundamental to the species' biology.

Aquarium Setup

A minimum 60-litre aquarium is recommended for a pair or small group of Wolterstorff's Pearl Fish. Use a fine sand or soft peat substrate to replicate the natural spawning medium. Include live plants such as Cryptocoryne, Java moss, and floating species like Salvinia or Limnobium. Provide spawning mops or peat moss for egg deposition. Lighting should be subdued, and filtration gentle to avoid strong currents. A secure, tight-fitting lid is essential. Maintain excellent water quality and cooler temperatures (20-25°C) to replicate natural conditions.

Feeding and Diet

As a carnivore, Cynolebias wolterstorffi requires a varied, protein-rich diet to maintain health and colour. Offer high-protein live and frozen foods such as bloodworms, daphnia, brine shrimp, and other small invertebrates daily. Quality carnivorous prepared foods may be accepted after acclimation. Live and frozen foods are essential for conditioning and breeding. Feed small portions twice daily, removing uneaten food promptly to maintain pristine water quality. Variety and freshness are critical for optimal health and vibrant colouration.

Behaviour and Temperament

Wolterstorff's Pearl Fish is a peaceful species that spends most of its time exploring the lower and middle water column. Males may display to each other during courtship with flared fins and vibrant colour displays, but serious aggression is rare. These fish have a naturally short lifespan of typically 6-12 months, reflecting their annual biology. They appreciate a dimly lit aquarium with plenty of cover. They are not competitive feeders, so avoid housing them with boisterous or fast-moving species.

Suitable Tank Mates

Cynolebias wolterstorffi is best kept species-only to accommodate its unique breeding biology and short lifespan. If tankmates are used, only very calm, similarly sized fish that share the same water requirements and will not outcompete it for food should be considered. Avoid aggressive fish, fast boisterous feeders, large predatory fish, fin-nipping species, and very small shrimp or fry that may be eaten. A calm, quiet environment is essential for this delicate annual killifish to thrive.

Breeding

This is a seasonal killifish that typically lays eggs in substrate. Condition a pair or small group with high-quality live foods, then provide spawning media such as peat moss or fine sand. Breeding usually requires a soft, peat-based spawning medium and careful incubation of the eggs in slightly damp conditions. Fry are small and need tiny live foods such as infusoria or newly hatched brine shrimp. Breeding success depends on careful egg management, cooler water temperatures, and matching seasonal conditions.

Why Buy from Tropical Fish Co

Tropical Fish Co is a trusted UK supplier of rare and specialist tropical fish, including hard-to-find annual killifish species like Cynolebias wolterstorffi. We guarantee healthy, well-conditioned stock, expert care advice, and secure nationwide delivery. Every fish is quarantined and inspected before dispatch, ensuring you receive only the finest specimens. Whether you're setting up a dedicated killifish tank or adding a rare species to your collection, Tropical Fish Co offers unmatched quality and customer service. Order online today and experience the beauty of Brazilian seasonal killifish.