Translation Series No.1211

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- 64 - It is found that the sexual figure for both sea year classes is very different. It amounts to 0.446 ± 0.0195 in group A.1+ and to 0.260 ± 0.255 in group A.2+. This difference points to the fact that during the third year in the sea at least as many males have migrated as females. The sexual ratio can therefore not be considered as constant. Since the strength of the year classes and with it the ratio between the two sea year classes A.1+ and A.2+ changes annually, the sexual composition of the exploited stock must also undergo this change. It is thus not the numerical ratio [ p. 263] of the sexes in the total catch that deserves our special attention but that in.the two age groups. Since the sea year class A.2+ in the sea comprises 74 per cent females) these must also predominate on the spawning ground. As has already [19 . 264] been explained, the missing males of this age class can be replaced by the numerous emigrating younger males. This, however, does not provide the solution for the problem of the sexual ratio on the spawning ground. When, for example, two very weak year classes follow on an exceptionally strong year class, then it must be taken into account that the younger males and grilse of the two weak year classes are not present in numbers sufficient for the females of the strong year class. Here nature has obviously taken precautions through the mature parr; because these fish were not subject to the strong depletion of the stock in the sea they are probably always present in sufficient numbers in the rivers. . 3.2. The conditions of the gonads According to A. Backmann (1929) there are two conceptions com- bined in the word "maturation": the process of the development from the juvenile fish to the sexually mature one during its first period of life,' 'Which happens, only once, and the obtaining of sexual maturity (sexmsa
cycle) during the second . period of life, whih is usually repeated period- ically. Fig.'14. Long gonad of a female of the sea year class A.2+. (a) full view, .(b) partial view, (c) gonadal discs. In the female the primitive germ cells give rise to the oogonia through mitotic divisions. The oogonia grow into oocytes of the first order. The meiosis that follows leads through oocytes of the second. order to the
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FISHERIES RESEARCH BOARD OF CANADA
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sos-2cto—lo-31 DEPARTMENTOFTHESEC
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• 6.1. Previous investigations 17
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-5-. and Kerr very much later menti
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treated as a quality, a special pop
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• -9-- per cent). Furthermore, th
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• - 11 - fishery, mentions the gr
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• - 13 - in LiepUva. These voyage
Page 17 and 18: • 1948/49 545 1949/50 730 1950/51
Page 19 and 20: • 2.2.1. River fishing - 16- The
Page 21 and 22: - 18- are 50 norsels, 60 to 80 cm l
Page 23 and 24: • nets give better results is onl
Page 25 and 26: • • G Fig. 4. End buoy for salm
Page 27 and 28: • with • Total length (cm) Mout
Page 29 and 30: • • - 25- of Bothnia. In the fa
Page 31 and 32: • • - 27- increase the catch. S
Page 33 and 34: • of • fishing representsavalue
Page 35 and 36: • to lower figures than in the fa
Page 37 and 38: • • Umfang = Cire umference - 3
Page 39 and 40: • - 35 - and nape corresponds to
Page 41 and 42: • • / 100 50 Selektion Selectio
Page 43 and 44: - 39 - In Table 9 have been calcula
Page 45 and 46: . Table 10. Number of salmon per 10
Page 47 and 48: • Table 11. Number of salmon per.
Page 49 and 50: • - 45 - cza-ci, es When consider
Page 51 and 52: - 47 - If We examine once more the
Page 53 and 54: - 49 - German fishermen work during
Page 55 and 56: • - 51 - is true, have to be corr
Page 57 and 58: Table 16. Seasonal yields of the fi
Page 59 and 60: Table 17. Monthly average weights o
Page 61 and 62: - 57 - In February and March hardly
Page 63 and 64: • Table 20. Additional catch of c
Page 65 and 66: • 100 50 60 100 cm Totallarle . 2
Page 67: • subject to an error of ± o.op9
Page 71 and 72: • their third year. , Recruitment
Page 73 and 74: 50 r-■ 2 / bet; 56cm = 1 fis 1 li
Page 75 and 76: • - 71 - ovary that has already b
Page 77 and 78: 5 - 73 - April 1960 the diameter of
Page 79 and 80: - 75 - oocytes can be demonstrated
Page 81 and 82: . ineftlerer Mean OocytendurcArness
Page 83 and 84: - 79 - furnish the energy fer the s
Page 85 and 86: ' 1741 salmon, which were.caught be
Page 87 and 88: • - 83- the series of measurement
Page 89 and 90: - 85 - the relative amount of eggs
Page 91 and 92: - 87 - The calculation of a formula
Page 93 and 94: - 89 - area of distribution is form
Page 95 and 96: - 91 - as percentages of thé recov
Page 97 and 98: Table 22. The recapture of tagged s
Page 99 and 100: • II> Three conclusions can be dr
Page 101 and 102: • 6 65- 64 - 62-. 61 - 6 . 5 . 59
Page 103 and 104: • - 99 - fish. The tagging does n
Page 105 and 106: - 101 - tagging experiments'that sa
Page 107 and 108: - 103- Renne Bank in about 60 m dep
Page 109 and 110: • 9:1 0 a) el-4 o (XI -P CNI 4- o
Page 111 and 112: 14,3 14,3 30,7 31,3 27,7 6,0 15,0 1
Page 113 and 114: Table 26. Catches of salmon in the
Page 115 and 116: - 111 - between Hela and Kahlberg r
Page 117 and 118: • - 113- 5 .. Age and growth of t
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cm 100 80 60 40 - 1 15- customarily
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found can be used for the recalcula
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v 0 00 0 I I - 119- of the scales.
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- 121 - The interpretation of the y
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• - 1 23 - the age groups 2.B to
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• L s - L c r s 0.85 Smolt Ls = l
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5.3. The'age composition of the Ger
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-129- with shares in the catch of o
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"ervoct. Yeer-Le- -e-t. '4.y-c.1*.e
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1955 1 2 3 4 23 3 61 506 7 3 135 21
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- 135 - yeAy-ctt4 thé explanation
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• • _ Table 33. The composition
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Table 34. Composition by age of cat
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- 141 - yeAy-cle..es Table 35. The
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- 143 - • U7,) tdL comparablenece
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• whereas the present data .(1957
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Sin% 0,1 2,8 37,0 96,8 100,0 - 147-
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• - 149 - these results 38 per ce
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• • Number of salmon J. en1967
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4. number 50 e" • ); e e , lot nb
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they take account of the annual cha
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• -157- and in the stock are bein
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Table 43. Mean lengths of age group
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• - 161 - of these catches has be
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- 163 - of enolt in Fig. 36. From a
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--165 - increase'in weight is more
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• rl -P b..0 -e nzi -ri r-1 gl a)
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- 169 - CLA‘s set of smolt of 193
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Year's sets of smolt CILS present 7
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- 173 - necessary to follow the gro
Page 179 and 180:
- 175 - • been ascertained from t
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(after K. A. Pyefinch 1955). — 17
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• gadids and sticklebacks (after
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- 181 - especially decisive in, the
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6.3.1. Seasonal fluctuations 36,9 2
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• Number of Months Gear salmon in
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MagerdW hing 40 , 20 Filling of Sto
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Deep could be examined. - 188 - Chr
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- 190 - salmon . switch over to the
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• - 192 - recognizable after seve
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- 194 - amount of food. Under-consi
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- 196- expenditure, composition in
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• - 1 98- the stock losses are co
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NUmber of salmon per Z Weigh- Seaso
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• 'Table 55. Values of the total
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- 204 experiment were about 40 per
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- 206- strength of the stock N pert
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• N„ Z o = cf„ (M1- T) -- In
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— 210— the coefficient for the
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- 212- In a further paper Piggins (
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- 214- shifted and the fOod supply
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- 216 - concerns the yield of captu
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nachafter 00 04 0,3 0,4 2 1 0,5 6 9
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• 1. (5 100 000) (4 250 000) 4 25
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• •em.ilts - 222 - in an error
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• - 224- BRANDT, A. y. , 1959: Fa
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- 226 - Paw, T. H., 1938: Fluctuati
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- 228- PETERSEN, C. G. .11, and Orr
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Table I. Captures per unit effort w
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Table II. Captures per unit effort
Page 239 and 240:
• Yea.r Sweden Continuation Table
Page 241 and 242:
Table VI. Ratio between fork le . B
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