Acipenser stellatus, commonly known as the Russian sturgeon, is a critically endangered species of fish belonging to the family Acipenseridae. This ancient fish, with an evolutionary history dating back millions of years, is characterized by its distinctive elongated body, bony plates, and a long, pointed snout. Its presence in various ecosystems across its range has made it a subject of ongoing research and conservation efforts.
Description and Characteristics
The Russian sturgeon (Acipenser stellatus) is a large, robust fish that can reach a maximum size of 250.0 cm. Its body is elongated and fusiform, tapering towards the tail. It possesses five rows of bony plates, known as scutes, running along its back, sides, and belly. The dorsal scutes are particularly prominent and form a distinct row along the midline of the back. Its snout is long, pointed, and slightly upturned, giving it a characteristic “sturgeon” look. The mouth is ventral and located on the underside of the snout. The Russian sturgeon has a distinctive color pattern, with a dark gray or brown back, lighter sides, and a white or yellowish belly. It has four barbels on its underside, which it uses to detect food on the bottom of the seafloor.
Habitat and Occurrence
Acipenser stellatus is a demersal fish, primarily inhabiting the bottom layers of the water column. Its depth range is typically between 10.0 and 100.0 meters, although it can occasionally venture into shallower waters. The Russian sturgeon is found in the Black Sea, the Sea of Azov, and the Caspian Sea. Its occurrence is primarily confined to these marine zones, with a strong preference for brackish waters, especially estuaries and coastal areas. However, they can be found in freshwater rivers, particularly during spawning migrations.
Taxonomy
The species Acipenser stellatus belongs to the Class: Chondrostei, Order: Acipenseriformes, and Family: Acipenseridae. This classification places it within a group of ancient, cartilaginous fishes that have survived for millions of years. Their unique skeletal structure, distinctive body shape, and specialized feeding adaptations set them apart from other fish species.
Feeding
Acipenser stellatus is a bottom feeder, relying on a diet of invertebrates, crustaceans, and small fish. Its long snout and sensitive barbels allow it to detect and capture prey buried in the sediment. The Russian sturgeon has a powerful jaw that enables it to crush hard-shelled invertebrates and extract their fleshy contents. This feeding strategy is crucial for its survival in the benthic environment, where it competes for food with other bottom-dwelling organisms.
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