About the Sturgeon Touch Exhibit

The Russian sturgeon (Acipenser gueldenstaedtii) is native to Eastern Europe. Like many species of sturgeon, the Russian sturgeon is anadromous, meaning it spends part of its life in freshwater, such as rivers, and part of its life in seawater. While young, Russian sturgeon will spend several years in freshwater to mate and reproduce then migrate back to the oceans as adults.

Because this species is a member of both the freshwater and ocean ecosystems, the Russian Sturgeon has a greater natural impact on other species than an organism who does not occupy multiple ecosystems. The eggs of the sturgeon provide a large and vital food source for many other species (both aquatic and terrestrial), as do the recently hatched young. During its time in seawater habitats, the Russian sturgeon acts as an important predator on benthic, or bottom dwelling, invertebrates such as crustaceans and mollusks.

The family that Russian sturgeon belong to is called Acipenseridae and is comprised of approximately 25 species of fish, all commonly known as "the sturgeons." Sturgeon species are characterized by a cartilaginous skeleton, rows of bony plates on the back and sides of the body, a heterocercal (asymmetrical) tail and four whisker-like sensory organs called barbels located under their chins, also called rostrums. This family of fishes evolved approximately 200 million years ago, which makes them the oldest group of bony fish still alive today! The only living fishes that outdate the sturgeon are sharks and stingrays.

Although it evolved separately from the sharks, the cartilaginous skeleton of sturgeon is similar in form and function to that of a shark. Many large fish, like the sturgeon which are known to reach up to 25 feet in length, have evolved cartilaginous skeletons. One hypothesis as to why this is is that cartilage is far less heavy than bone, allowing primitive fishes like sturgeon and sharks to maintain better buoyancy in the water. Although the skeleton of the sturgeons is made of cartilage, they do possess bony plates called "scutes" which line their backs and sides. These scutes create a "suit of armor" protecting the animal from environmental injuries and even predators.

The shape of the sturgeons tail, or caudal fin, is known as "heterocercal". This means that the upper lobe of the fin extends beyond the lower lobe, and the backbone extends nearly to the tip of the upper lobe of the caudal fin.

The barbels hanging from the "chin," or rostrum of sturgeon are a sensory organ used in finding food. They function in a similar way to the barbels, or whiskers, of a catfish. A sturgeons barbels are chemosensory and can both smell and taste food items hiding in rocks or substrate, allowing the animal to quickly detect and capture small prey items.