. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 492 CALIFORNIA FISH AND GAME mm. In six months A has grown to a length of 185 mm. and has added 25 circuli while B has attained the length of 200 mm. and also has added 25 circuli. If small samples were made at these times they might contain fish nearlj^ all of which were like A or nearly all like B. In either case the circulus averages would be similar but length averages would be much different. \20^. 70 60 z o 50 o o > o 30 c 20
. California fish and game. Fisheries -- California; Game and game-birds -- California; Fishes -- California; Animal Population Groups; Pêches; Gibier; Poissons. 492 CALIFORNIA FISH AND GAME mm. In six months A has grown to a length of 185 mm. and has added 25 circuli while B has attained the length of 200 mm. and also has added 25 circuli. If small samples were made at these times they might contain fish nearlj^ all of which were like A or nearly all like B. In either case the circulus averages would be similar but length averages would be much different. \20^. 70 60 z o 50 o o > o 30 c 20 10 JULY AUG^ ScPT OCT NOV DEC JAN FEB. MAR APRIL MAY JUNE FIGURE 5. Increase in length of fish and in number of scale circuli for class 1 + during 1930-31 When regular sampling began in June, 1930, class 1+ was the young- est to be found (Figure 4). Class 1+ continued in the same relative abundance for the ensuing 13 months. In April, 1931, fish which were a year younger than this dominant class made their appearance in the area but in very small numbers. This group had very probably been present all of the time but the fish were too small to be caught. It is re- markable how much less numerous this class was than the class of the same age a year before. From this fact, it may be concluded that there is great variation in the mortality of the different year classes. When the writer began examination of the scales of the blue rockfish in June, 1930, ''annulus" C of class 1+ was forming or had recently been completed. During the ensuing year, circuli were apparently added in a very regular manner. However, at the end of the collecting in June, 1931, the scales of class 1+ taken in May and June were examined criti- cally for irregularities, and although the irregularities found were very poorly defined, the examination shoAved that 31 percent had previously formed ' * annuli.'' A little more than half of these annuli were of the single type, the rest were paired. The averag
Size: 2262px × 1104px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcaliforniadeptoffishandgame, bookauthorcaliforniafish
