The Diet of Freshwater Sturgeons

Sturgeon is typically found in large rivers and estuaries near the Pacific Ocean. Some species of sturgeon can grow to be very large, up to 1400 lbs. and 20 feet in length. Normally, they have cylindrical bodies covered in scutes, or armor-like scales, along with large mouths on the bottom side of the head with whisker-like appendages used in locating food.

* Locating Food

Traditionally, sturgeons have very bad eyesight and make good use of their whiskers when searching for food. They  use the whiskers to comb the bottom of the river or lake as the sturgeon is swimming over. To increase the coverage area of their food search, sturgeons will sometimes wag their head from side to side. Also, many scientists believe that sturgeon carry their taste buds on the outside of their mouths, which assists them in detecting prey.

Once a sturgeon has located something it deems appropriate to eat, it simply sucks it up with its mouth like a vacuum cleaner. Usually, the food is swallowed straight into the fish’s stomach. Only the largest fish ever get chewed up after they are pulled into the sturgeon’s mouth. Due to the relatively large size of sturgeon and the relatively small size of their food, sturgeons spend almost all of their time scouring for meals.

* Normal Diet

Being bottom-feeders, sturgeon have several sources of food that can be found along the river bottom. Insect larvae are a staple of the sturgeon’s diet, along with mollusks and other small invertebrate that live in the mud. They will normally feed on any other dead fish as well, which are also generally found along the bottom. Sturgeon also feed on many other species of live fish, such as smelt, shad and sculpin, especially when those fish are in the middle of their spawning process. Depending on their particular environment, sturgeons have also been known to thrive off of clams and crayfish.

* General Outlook

With the large possible habitats for sturgeon, their outlook varies from region to region. In some areas, sturgeons have become known as an endangered species due to their relatively small populations. In other regions, there are so many sturgeons that they can be harvested and used to support local fisheries. These fish are not only considered a valuable commercial food source because of its meat, sturgeon eggs are also typically used in creating caviar. Many of these areas also impose size and quantities limits on fisherman to better control the sturgeon population and secure it for generations to come.

Sources:

Pacific States Marine Fisheries Commision, http://www.psmfc.org