. The Canadian field-naturalist. 1984 Dadswell: Status of the Shortnose Sturgeon 77. Figure 2. Canadian distribution of the Shortnose Sturgeon (Acipenser hrevirostrum). Courtesy of D. E. McAllister, National Museum of Natural Science. Fredericton (Dadswell, personal observation). Juve- niles spend their first years in deep riverine portions of the upper estuary, predominantly in fresh water (Dadswell 1979). General Biology Shortnose Sturgeon spawn during early spring in the freshwater portions of estuaries or in rivers. Spawning occurs during flood conditions at water temperatures of 10-I2°C (
. The Canadian field-naturalist. 1984 Dadswell: Status of the Shortnose Sturgeon 77. Figure 2. Canadian distribution of the Shortnose Sturgeon (Acipenser hrevirostrum). Courtesy of D. E. McAllister, National Museum of Natural Science. Fredericton (Dadswell, personal observation). Juve- niles spend their first years in deep riverine portions of the upper estuary, predominantly in fresh water (Dadswell 1979). General Biology Shortnose Sturgeon spawn during early spring in the freshwater portions of estuaries or in rivers. Spawning occurs during flood conditions at water temperatures of 10-I2°C (Dadswell 1979; Taubert 1980). Eggs are probably broadcast and fertilization is external. Upon fertilization, the eggs become adhesive and attach to bottom materials (Meehan 1910). Hatching takes place in 13 days at 10°C (Meehan 1910). At hatching, larvae are 9-12 mm in length, grey-black and demersal (Taubert and Dadswell 1980). Growth is rapid during the first year of life (Pekovitch 1979). Further growth varies greatly depending on lati- tude, the fastest growth occurring among southern populations, but fish from northern populations attain a larger size. In the Saint John River, , the species attains 50 cm fork length after 10 years, 90 cm fork length after 25 years, and 100 cm fork length after 35 years. Maximum known size of Shortnose Stur- geon in the Saint John River is 143 cm total length. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Ottawa Field-Naturalists' Club. Ottawa, Ottawa Field-Naturalists' Club
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