Sturgeon
Acipenseridae
Characteristics Of Sturgeon
Sturgeon are prehistoric fish that have lived for around 200 million years. The earliest fossils are from the Jurassic period, found in China, and dated to be 125-150 million years old.
The present form of sturgeon is very similar, basically unchanged, from sturgeon dating back 65 million years to the Cretaceous period to the time when the Dinosaurs became extinct.
There are 29 recognized sturgeon species worldwide (as recognized by the World Sturgeon Conservation Society) and they only live in the Northern Hemisphere from the South Arctic Ocean to around the Tropic of Cancer. In North America there are nine species: Alabama, Atlantic, Green, Gulf, Lake, Pallid, Shortnose, Shovelnose, and White.
Sturgeon are a bizarre fish, with many characteristics uniquely their own. First of all being their scutes; All sturgeon have 5 rows of bony plates called scutes. The picture below shows all 5 rows. Starting at the top; Ventral/Belly - Lateral/Side - Dorsal/Top - Lateral/Side - Ventral/Belly.
notes
Sturgeon is the common name for the 27 species of fish belonging to the family Acipenseridae. Their evolution dates back to the Triassic some 245 to 208 million years ago.[2] The family is grouped into four genera: Acipenser, Huso,Scaphirhynchus and Pseudoscaphirhynchus. Four species may now be extinct.[3] Two closely related species, Polyodon spathula (paddlefish) and Psephurus gladius (Chinese paddlefish, possibly extinct) are of the same order,Acipenseriformes, but are in the family Polyodontidae and are not considered to be "true" sturgeons. Both sturgeons and paddlefish have been referred to as "primitive fishes" because their morphological characteristics have remained relatively unchanged since the earliest fossil record.[4][5] Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America.[6] they eat Food consumption studies indicate lake sturgeon feed on almost anything they can find, which includes invertebrates, insect larvae, crayfish, worms and mollusks. While these studies found that sturgeon eat some fish andfish eggs, they were not a large component of the lake sturgeon diet.