Endangered
Green sturgeon
Acipenser medirostris
Green sturgeon is an animal in the family Acipenseridae (order Acipenseriformes) — Acipenser medirostris, recorded as Endangered.
Appearance
The sturgeons themselves are not ancestral to modern bony fishes but are a highly specialized and successful offshoot of ancestral chondrosteans, retaining such ancestral features as a heterocercal tail, fin structure, jaw structure, and spiracle. Sturgeons are highly adapted for preying on bottom animals, that they detect with a row of sensitive barbels on the underside of their snouts. Of 25 extant species, only two live in California, the green sturgeon and the white sturgeon (S. Transmontanus).
Green sturgeon can reach 210 cm (7 feet) in length and weigh up to 160 kg (350 pounds).
Range and habitat
The high fecundity that comes with large size allows them to produce large numbers of offspring when suitable spawning conditions occur and to make up for years of poor conditions. The widespread ocean distribution of green sturgeon ensures that most of the population is dispersed and less vulnerable than they are in estuaries and freshwater streams. As an anadromous species, green sturgeon enters rivers mainly to spawn.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
Sturgeon, as benthic feeders, have specialized subterminal mouths that allow them to suction and grind a variety of hard-shelled prey like crustaceans and clams. While their primary diet usually consists of mollusks and crustaceans, sturgeons can alter their food sources depending on availability.
For instance, juvenile and subadult white sturgeon often consume Corophium amphipods and mysid crustaceans like opossum shrimp, whereas adults feed more on clams and fish eggs. Adult green sturgeon feed in estuaries during the summer.
In crisis
Several conservation efforts have been implemented to protect the Southern Distinct Population Segment (sDPS) of green sturgeon, addressing key factors that threaten the species. California has enacted strict regulations, among them year-round bans on sturgeon fishing in key river sections, restrictions on tackle, and increased fines for poaching. Even so, there is still a lack of screening criteria specific to green sturgeon, and the overall benefits of these measures remain unclear.
Although the number of green sturgeon salvaged is generally low, these actions help protect individuals from harm. High spring flows are crucial for successful spawning, and their reduction due to water management poses threats.
CITES lists this taxon on Appendix II. Confirm the current appendix on the CITES checklist.
Green sturgeon is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Green sturgeon, Wikidata item Q1552149. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.
