Flumiantis Pearl Fish (Cynolebias fulminantis) — 3-4cm

Overview

The Flumiantis Pearl Fish (Cynolebias fulminantis) is a rare, striking killifish native to South America. Reaching just 3cm in length, this semi-aggressive species is prized for its pearl-like sheen and unique behavior. As an annual killifish adapted to temporary habitats that dry seasonally, Cynolebias fulminantis has a compressed life cycle and unique reproductive biology. Available for sale UK from Tropical Fish Co, this rare species rewards expert aquarists with breeding challenges and captivating displays in species-only aquariums.

Appearance and Coloration

The Flumiantis Pearl Fish displays striking pearl-like colouration with a compact, robust body adorned in soft blues, greens, and yellows with iridescent pearly spots scattered across the scales. Males are intensely coloured with pronounced finnage and a bold presence, especially during courtship. The scales shimmer with a metallic lustre under subdued lighting that creates a pearl-like effect. Females are smaller, plumper, and more subdued in colour with shorter finnage. In a planted tank with dark substrate, the pearly sheen becomes even more visible and eye-catching.

Natural Habitat

Cynolebias fulminantis inhabits seasonal freshwater pools and wetlands in South America. 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, 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 20-litre aquarium is sufficient for a pair or small group of Flumiantis 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, as annual killifish are sensitive to pollution and stress.

Feeding and Diet

As a carnivore, Cynolebias fulminantis requires a varied, high-protein diet to maintain health and colour. Offer a varied diet of live and frozen foods such as bloodworms, daphnia, brine shrimp, and other small meaty foods daily. Some individuals may accept quality carnivore pellets or prepared foods 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

The Flumiantis Pearl Fish is a semi-aggressive species that spends most of its time exploring the lower and middle water column. Males can be territorial towards each other, especially during courtship and spawning, with displays of flared fins and bold colour. Serious aggression is usually limited to conspecifics. 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 and territorial boundaries.

Suitable Tank Mates

Cynolebias fulminantis is best kept species-only to accommodate its unique breeding biology and territorial nature. If tankmates are used, only very carefully selected robust, similarly sized fish in a larger setup may be suitable, though this is generally not recommended. Avoid small fish that can be swallowed, slow-moving or long-finned fish, aggressive or highly active species, and tiny shrimp or other small invertebrates. A calm environment is essential for this annual killifish to thrive.

Breeding

This is likely an annual killifish that requires a soft, slightly acidic spawning medium. Condition a pair or small group with high-quality live foods, then provide spawning media such as peat moss or fine sand. Breeding typically requires careful collection and incubation of eggs in damp peat or similar substrate. Fry usually need small live foods such as infusoria or newly hatched brine shrimp. Breeding success depends on careful egg management, precise water conditions, and matching seasonal conditions. Remove adults to prevent egg predation.

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 fulminantis. 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 fascinating world of South American annual killifish.