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Uniandra contradens, also called Green Golden Stripe Clam, is a freshwater mussel from Africa that remains rather uncommon in the aquarium trade. It belongs to the family Unionidae and lives an entirely benthic life, partly buried in the substrate. Its sturdy shell is generally greenish to olive brown and may display a golden longitudinal stripe, which explains its commercial name. This wild-collected species requires clean, well-oxygenated, biologically mature water. It filters suspended particles and is best kept in an aquarium dedicated to invertebrates, where feeding can be controlled and copper-based treatments avoided.

General species description

Uniandra contradens is a large African freshwater mussel belonging to the genus Uniandra. Like other unionids, it has two shell valves and feeds by filtering water. It usually rests on or partly within the bottom, with its siphons directed toward the water column. Its aquarium interest comes mainly from its unusual appearance and its role as a natural filter feeder, rather than from constant visible activity. It is a relatively uncommon species in the specialty trade. Available specimens are collected from the wild, so gradual acclimation and stable water conditions are essential.

Geographic origin and biotope

Its native range lies in central Africa, within the Congo Basin and associated freshwater systems. It inhabits permanent waters that remain sufficiently oxygenated to support filter feeding. The habitat includes slow to moderately flowing areas with sand, mud, or small gravel on the bottom. In an aquarium, the goal is to provide a clean environment without waste accumulation while maintaining some water movement. Sudden parameter changes, oxygen-poor water, and very compact substrates should be avoided.

Specific locality and local name

Uniandra contradens is associated with freshwater habitats in the Congo Basin. The English trade name Green Golden Stripe Clam is the name most commonly used by aquarists to identify it. No precise local vernacular name is included here. In the trade, it may also be sold simply as an African freshwater mussel or clam. Identification should ideally consider shell shape, coloration, and the declared origin of the specimen.

Appearance and physical characteristics

The shell is thick, elongated, and fairly rounded, with coloration ranging from olive green to greenish brown. A pale or golden mark may run lengthwise along the valves, creating the distinctive pattern associated with the name Green Golden Stripe. The valves are joined by a strong hinge and covered by a protective periostracum. The animal itself remains mostly hidden; only the siphons may be visible while it filters. Adult specimens may reach about 10 cm, depending on growing conditions.

General diet

Uniandra contradens is a filter feeder that captures plankton, bacteria, and fine organic particles suspended in the water. An aquarium that is too clean and contains very little suspended food can therefore become unsuitable over time. It is preferable to maintain mature water and, when necessary, provide small amounts of liquid invertebrate food or phytoplankton. Feeding should remain moderate to prevent excessive pollution. Good oxygenation, gentle filtration, and the absence of copper are priorities; medications should be selected very carefully.

Essential data

• Name of the river of origin: Congo Basin
• Local name used: Green Golden Stripe Clam
• Origin of the scientific name: Uniandra is the genus name; contradens is the specific epithet.
• Full-name etymology: Uniandra refers to the construction of the genus name; contradens comes from the Latin contra, “opposite,” and dens, “tooth.”
• Common/vernacular names: Green Golden Stripe Clam; African freshwater mussel
• Family: Unionidae
• Subfamily: Unioninae
• Name pronunciation: you-nee-AN-dra con-tra-DENS
• Discovery: Isaac Lea, 1840
• Maximum adult size: About 10 cm
• Water temperature and pH: Stable tropical freshwater, clean and well oxygenated
• Stream appearance and surrounding vegetation: Permanent waters, slow to moderately flowing areas, tropical riparian vegetation
• Typical tankmates: Peaceful benthic invertebrates and small non-predatory fish
• Temperament and behavior: Peaceful and secretive; partly burrows and filters the water
• Water depth: Benthic areas of variable depth
• Sexual dimorphism: Little apparent externally
• Bottom configuration and flow: Sand, mud, or fine gravel; low to moderate flow

In your aquarium

Keeping Uniandra contradens successfully requires a mature aquarium with soft substrate, moderate water movement, and a regular supply of fine suspended food. Because this is a wild-collected and relatively uncommon species, overcrowding and repeated handling should be avoided. Monitor oxygenation, remove copper-containing medications, and keep water quality consistent. Excessively strong filtration or a sterile aquarium may prevent it from feeding properly.