. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 38 CALIFORNIA FISH AND GAME 22 C 20 C ISC 16C 14 C. DAYS SINCE SPAWNING FIGURE 6. Relationship between age (since time of spawning) and length of sturgeon larvae at various water temperatures observed during sampling in the Sacramento River in 1973. These relationships were estimated from the regressions in Figure 5. if larval length and approximate developmental temperature are known, an estimate of larval age can be interpolated fro
. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 38 CALIFORNIA FISH AND GAME 22 C 20 C ISC 16C 14 C. DAYS SINCE SPAWNING FIGURE 6. Relationship between age (since time of spawning) and length of sturgeon larvae at various water temperatures observed during sampling in the Sacramento River in 1973. These relationships were estimated from the regressions in Figure 5. if larval length and approximate developmental temperature are known, an estimate of larval age can be interpolated from this graph. DISCUSSION While small, the catch of 246 larvae provided good information on the location and timing of sturgeon spawning in the Sacramento River in spring 1973. The majority of spawning occurred from the vicinity of Knights Landing upstream to just above Colusa. Spawning was most intense during March and April, but probably began before mid-Feb- ruary since larvae were captured on the first day of sampling. Information from my study generally agrees with that for other species of sturgeon in other river systems. Spawning dates for many species range from March to early July and spawning temperatures range from 9 to 24 C (48 to 75 F) Nikolskii 1961; Berg 1962; Geibel 1966; Magnin 1966). Some European sturgeon have two or more races migrating and spawning at different times (Gerbilskii 1951; Nikolskii 1961; Berg 1962). My study was not designed to determine if several spawning races exist in the Sacramento River system; however, the seasonal nature of sport catches (Miller 1972) suggests that the run of sturgeon moving upriver in late winter and spring is the major, if not the only, spawning group. Sturgeon spawning sites are described as having gravelly or rocky bottoms where currents are moderate to fast (Dees 1961; Nikolskii 1961;. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - colora
Size: 1725px × 1449px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcaliforniadeptoffishandgame, bookauthorcaliforniafish
