Diamond Sturgeon Care Guide - Size, Habitat & Breeding

The Diamond Sturgeon is a large, ancient-looking fish with an elongated body, a pointed snout and five rows of prominent bony scutes. Its back is usually grey-brown to olive, while the underside is paler, and the mouth is positioned beneath the head for feeding along the bottom. Four barbels around the mouth help it locate food in sediment.

This species is a powerful swimmer but is generally deliberate and composed rather than highly active in the way many aquarium fish are. It spends much of its time close to the bottom, using its sensitive barbels and electroreceptive organs to find prey hidden in sand, mud and gravel.

Young Diamond Sturgeon inhabit coastal and river environments, while adults undertake long migrations between the sea and large rivers. Their natural waters range from freshwater to brackish conditions and may include deep channels, broad estuaries and fast-flowing spawning areas.

Like other sturgeons, Diamond Sturgeon are evolutionary relics with a lineage stretching back more than 200 million years. They are threatened by overfishing, habitat alteration, pollution and the loss of migratory river routes, and wild populations have declined severely across their native range.

Diamond Sturgeon, also widely known as Russian Sturgeon, are native to the Black Sea, Sea of Azov and Caspian Sea basins, spanning parts of eastern Europe and western Asia. They are anadromous fish, moving between brackish coastal waters and freshwater rivers to reproduce.

Diamond Sturgeon require a specialist, very large coldwater system with excellent oxygenation, powerful biological filtration and generous swimming space. There is no genuinely suitable home-aquarium size: even a temporary juvenile holding system should be at least 10,000 litres, with a footprint of roughly 5 metres by 2 metres, while adult care requires a public-aquarium-scale tank or very large pond measured in tens of thousands of litres. Use a smooth sand or fine-gravel substrate, open bottom areas, strong circulation and rounded decor without sharp edges. Because this species becomes enormous, purchasing one for a normal aquarium is unsuitable and may be illegal depending on local regulations.

Up to about 235 cm (92.5 in) in exceptional individuals. Females are typically larger and heavier than males; many captive specimens remain considerably smaller than this maximum.

Diamond Sturgeon are bottom-feeding carnivores that consume aquatic insect larvae, worms, crustaceans, molluscs and small fish. Their downward-facing mouths and barbels are adapted for locating prey on or within the substrate. Captive specimens are generally offered sinking, high-protein sturgeon pellets supplemented with suitable frozen or fresh aquatic foods under expert supervision.

Diamond Sturgeon are not suitable for a conventional community aquarium. In properly licensed public-aquarium or specialist pond systems, they may coexist with other large, peaceful coldwater species such as compatible sturgeons, large carp and robust native river fish, provided that all inhabitants have ample space and similar water requirements. Avoid small fish, slow bottom dwellers and aggressive or territorial species, as the sturgeon may swallow small tankmates or be injured by fin-nipping and competition for food.

Diamond Sturgeon are not realistically bred in home aquariums. In specialist hatcheries, mature fish are conditioned in large, cool, highly oxygenated systems before spawning is induced or carefully managed. In nature, adults migrate into flowing rivers, where adhesive eggs are released over gravel and hatch into larvae that drift or settle downstream. They mature slowly, often taking many years, and females generally do not spawn every year.

Females usually grow substantially larger and heavier than males and may develop a broader, deeper body when mature. External differences are otherwise subtle, and reliable sexing often requires examination by an experienced specialist or imaging of mature fish.