Several species of sturgeon are harvested for their roe, which is processed into the luxury food caviar. [23] Sturgeons feed non-visually.

and V.G. Sturgeons are characterized by a long snout with 4 barbels (stringlike appendages) underneath, a toothless mouth, and 5 rows of shieldlike, bony plates on the body.
Having no teeth, they are unable to seize prey, though larger individuals and more predatory species can swallow very large prey items, including whole salmon. 148–152 in N. Eldredge and S.M. [47] They are an ancient species that have survived for millions of years[48] but their future is threatened, due in part to their inherent ancestral characteristics and reproductive specificities. In that time, sturgeons have undergone remarkably little morphological change, indicating their evolution has been exceptionally slow and earning them informal status as living fossils.
[41][43], By the turn of the century, commercial production of sturgeon caviar in the US and Canada had come to an end.

[71], In heraldry, a sturgeon is the symbol on the coat of arms for Saint Amalberga of Temse.[72]. [33], The wide range of the acipenserids and their endangered status have made collection of systematic materials difficult.

[7][8][9] They also lack vertebral centra, and are partially covered with five lateral rows of scutes rather than scales. Critically Endangered, Working to sustain the natural world for the benefit of people and nature. [25] The electroreceptors are thought to be used in various behaviors such as feeding, mating and migration. Living fossils. [36], In currently accepted taxonomy, the class Actinopterygii and the order Acipenseriformes are both clades. 4. Those requirements may or may not be met every year due to varying environmental conditions, such as the proper photoperiod in spring, clear water with shallow rock or gravel substrate, where the eggs can adhere, and proper water temperature and flow for oxygenation of the eggs.

Notably, however, the cartilagineous skeleton is not a primitive character, but a derived one; sturgeon ancestors had bony skeletons. The sturgeon is a large, primitive, bony fish of class Actinopterygii, family Acipenseridae. The caviar was estimated to be worth around $2 million. Sturgeons are an ancient group; fossils are known that date back to the Upper Cretaceous (98.9-65 million years ago). [31][32] This is explained in part by the long generation interval, tolerance for wide ranges of temperature and salinity, lack of predators due to size and bony plated armor, or scutes, and the abundance of prey items in the benthic environment. Eight to 15 days are needed for the embryos to mature into larval fish. Sturgeons are characterized by a long snout with 4 barbels (stringlike appendages) underneath, a toothless mouth, and 5 rows of shieldlike, bony plates on the body. Researchers believe that several hundred years ago these fish reached th… ; and Atlantic and shortnose sturgeons in Atlantic coastal waters and rivers. [24], Many sturgeons leap completely out of the water,[26] usually making a loud splash which can be heard half a mile away on the surface and probably further under water. "Response properties of the electrosensory neurons in hindbrain of the white sturgeon, Acipenser transmontanus", "Outdoors: The lofty mystery of why sturgeon leap", "Sturgeons versus surgeons: leaping fish injuries at a level I trauma center", "Leaping sturgeon kills girl in boat on Florida river", "Evidence for a Slowed Rate of Molecular Evolution in the Order Acipenseriformes", "Craniata, (2) Subclass Actinopterygii-the ray-finned fishes", "Resolution of ray-finned fish phylogeny and timing of diversification", "The Tree of Life and a New Classification of Bony Fishes", 10.1371/currents.tol.53ba26640df0ccaee75bb165c8c26288, "World's Appetite For Caviar Sends Poachers After Columbia River Sturgeon", White sturgeon, Shovelnose sturgeon, American Paddlefish, "Seasonal occurrence of Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) in the St. Johns River, Florida", "Caspian States agree on quotas for wild caviar", "As Caviar Prices Skyrocket, Sturgeon Poachers Invade Pacific Northwest", "Sturgeon of North America (Acipenseridae)", "The IUCN Red List of Threatened Species", "Chinese Sturgeon Is on the Brink of Extinction After 140 Million Years", "Beluga Sturgeon Threatened With Extinction, Yet Caviar Quotas Remain Unchanged -- ScienceDaily", "Sturgeon more critically endangered than any other group of species", "Species, status and population trend of Sturgeon on the IUCN Red List of Threatened Species (pdf)", "Gesellschaft zur Rettung des Störs e.V. From McGill’s Redpath Museum. Fishing News Books, Osney Mead, Oxford, England. They feed on the bottom, using their protruding, sucking lips. (Russian version published 1948). There are 26 species of sturgeon and paddlefish in the Acipenseriformes group and many of these species are harvested as food. Washington Department of Fish and Wildlife, "Sturgeon More Critically Endangered Than Any Other Group of Species", "Biology of Fishes (chapter: Biodiversity II: Primitive Bony Fishes and The Rise of Modern Teleosts)", "Fish & Habitats– White Sturgeon (Acipenser transmontanus) in British Columbia", "Investigations of anadromous fishes of the Neuse River, North Carolina", "LIFE 04NAT/IT/000126 "Conservation and Breeding of Italian Cobice Endemic Sturgeon. Sturgeons are among the largest fish: some beluga (Huso huso) in the Caspian Sea reportedly attain over 5.5 m (18 ft) and 2000 kg[11] (4400 lb) while for kaluga (H. dauricus) in the Amur River, similar lengths and over 1,000 kg (2,200 lb) weights have been reported.

They do, however, still share several primitive characteristics, such as heterocercal tail, reduced squamation, more fin rays than supporting bony elements, and unique jaw suspension. It is one of Canada’s largest freshwater fishes. [30], ...in May, June and July, the rivers abound with them, at which time it is surprising, though very common to see such large fish elated in the air, by their leaping some yards out of the water; this they do in an erect posture, and fall on their sides, which repeated percussions are loudly heard some miles distance....[28], Acipenseriform fishes appeared in the fossil record some 245 to 208 million years ago (Mya) near the end of the Triassic, making them among the most ancient of still-living actinopterygian fishes. The negative impacts of overfishing, poaching, habitat destruction, and the construction of dams that have altered or blocked their annual migration to ancestral spawning grounds have taken a serious toll. The family is grouped into four genera: Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. [4][5] Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia and North America.[6].