Common names:shortnose sturgeon,pinkster (E), esturgeona museau court (F).Conservation status:Listed under the Endan-gered Species Act bythe USFWS, listed asthreatened in Canada.Identification: D 38–42, A 19–22 rays, 8–13dorsal scutes, 22–33 lateral scutes, 7–11 ventral plates. Body elongated, rostrum usually short but very variable. Two pairs of barbels present,always originating closer to the tip of snout than mouth. Mouth wide, upper lip indented in the middle and lower lip interrupted. Small denticlespresent on laterodorsal and lateroventral surface. Scutes usually lighter than surrounding body and undergo minimal absorption in very largeindividuals. Pre anal plates posterior to rectum vary in number (1–3) but never paired. Post dorsal plates are small, 1–2 and paired. Shortnosesturgeon may reach a size 1.5m and weigh 25kg but most fish caught are usually less than half that size. Color varies from overall peanut-butterbrown or black on dorsum turning lighter on lateral side with pronounced change to white or off-white on ventral surface. Juveniles coveredwith small black spots, not black saddle markings as in juvenile lake sturgeon, A. fulvescens. Drawing of a Hudson River 60cm adult byP. Vecsei. Distribution: Present along the east coast of North America in the lower portions of rivers. In Canada, it is known only from the SaintJohn River. In the United States, its range is disjunct with a 400km gap separating northern and southern populations. A gap in distributionoccurs from New Jersey to North Carolina. Unlike the Atlantic sturgeon, A. oxyrinchus, which commonly move along the coast, shortnosesturgeon are restricted to their rivers of origin. Abundance: Severely depleted throughout all of its southern range. Northern populations arethought to have always been much larger and may generate a flow of marine migrants who colonize new rivers (Kynard 1997). In such case, theHudson population of 40 000 adults is a likely source of emigrants. This phenomenon of marine migrants is poorly understood. All southernpopulations consist of less than the 1000 individuals deemed to be the minimum to sustain a viable population level for vertebrates (Thompson1991).The population in the St-John River, New Brunswick is much larger than previously thought and harbors the largest shortnose sturgeonin the world. Habitat and ecology: From spring until the early fall, shortnose sturgeon inhabit the deeper channels of freshwater and brackishzones of rivers. During this period of growth and feeding, these sturgeon ingest insects and crustaceans. With declining water temperatures,they are concentrated on wintering grounds (Bain 1997). On the Hudson River, non-spawning adults concentrate in brakish waters, and inspring they move upstream to the upper tidal zone (Geoghegan et al. 1992). Pre-spawning adults hold in pools near their spawning sites.Reproduction: Shortnose sturgeon are amphidromous. Length at maturity ranges from 45 to 55cm FL but age at maturity varies greatlybetween sexes and with latitude. Males are thought to spawn at intervals of 2 years while females at 3 to 5 year intervals (Kieffer & Kynard1996). Spawning takes place between late April and early May over gravel substrate but varies greatly with latitude. The eggs are adhesive andstick to the bottom. Threats: Dredging of large rivers such as the Hudson greatly increases siltation which reduces food availability during onsetof exogenous feeding of larvae. Dams have blocked access to spawning sites on many rivers. As the Hudson River stock recovers, poaching maybecome a problem. Conservation action: The listing of shortnose sturgeon under the U.S. Endangered Species Act has met variable results.The Hudson River stock has increased in number and is now considered stable. The Connecticut River stock has not increased markedly andsouthern populations continue to be threatened with extinction.