White sturgeon – Acipenser transmontanus

Acipenser transmontanus, commonly known as the white sturgeon, is a large, ancient fish species belonging to the family Acipenseridae. It is a prominent member of the order Acipenseriformes, which includes all sturgeons and paddlefish, and falls under the class Chondrostei, characterized by their cartilaginous skeletons.

Description & Characteristics

Acipenser transmontanus is a truly impressive fish, capable of reaching a maximum size of 610 cm (20 ft) in length. Its body is elongated and torpedo-shaped, with a distinct, pointed snout and a row of bony plates, or scutes, running along its back and sides. The color of Acipenser transmontanus can vary, ranging from light gray to dark brown, with lighter bellies. Their lifespan can extend to over 100 years, making them one of the longest-lived freshwater fish species.

Habitat and Occurrence

Acipenser transmontanus is a freshwater fish that prefers cool, clear waters. It is typically found in rivers, lakes, and estuaries, primarily in the Pacific Northwest region of North America. They inhabit a depth range of 1.0 – 122.0 meters, making them adaptable to various depths. The species is particularly abundant in the Columbia River and its tributaries, including the Snake River and the Fraser River. Their presence in these waterways makes them a significant part of the Pacific Northwest’s aquatic ecosystems.

Taxonomy

The species Acipenser transmontanus is classified as follows: it belongs to the Class: Chondrostei, Order: Acipenseriformes, and Family: Acipenseridae. This classification highlights its evolutionary history and unique features within the fish kingdom.

Feeding

Acipenser transmontanus is an opportunistic bottom feeder, primarily feeding on invertebrates like crustaceans, mollusks, and insects. Their diet can also include small fish and plant matter. They use their long, sensitive snouts to probe the bottom of the riverbed, searching for food. Their feeding habits contribute to their role in maintaining the ecological balance of the rivers they inhabit.