Ml \03 A METHOD OF MEASURING FISH EGGS By H. von Bayer, C. E. Architect and Engineer, United States Bureau of Fisheries J- Paper presented before the Fourth International Fishery Congress held at Washington, U. S. A., September 22 to 26, 1908 BULLETIN OF THE BUREAU OF FISHERIES : : : : : VOL. XXVIII. P. 1009-1014 Document No. 703 :::::::::::::::: : : : : Issued April. 1910 H-'i " //■■-'•^ s- l/'2-4 APR 15 1910 ■•b' ^' vV A cA A ^ cr A METHOD OF MEASURING FISH EGGS. By H. VON BAYER, C. E., Archilecl and Engineer, United States Bureau oj Fisheries. In a well-regulated fish hatchery it becomes at times necessary to count the eggs of fishes, so as to know the quantity on hand and prepare for certain shipments of eggs as well as for the future care of the fry. The methods thus Fig. I . — Metal trough for use in determining diameter of fish eggs. far employed have been to determine by actual count the number of eggs con- tained in one liquid quart measure, and then to multiply said number by the number of quarts of eggs on hand ; or to weigh one liquid quart of counted eggs, next to weigh all the eggs on hand, and then by simple proportion to determine the number of all the eggs. The new method proposed by the writer is first to determine the diameter ° of one egg, and then to enter with the value of said diameter a table or diagram a By diameter is here understood the diameter of the egg including its surrounding matrix, if any. lOII IOI2 BULLETIN OF THE BUREAU OF FISHERIES. in which the corresponding number of eggs per Uquid quart or other unit measure is found by inspection. To determine the diameter of one egg of a certain species of fish, a V- shaped metal trough with scale engraved thereon is used, in which a certain number of eggs is placed one egg deep in a row, the eggs touching each other; the space occupied by the eggs is then read on the scale; this reading, when divided by the number of eggs in the trough, will give the diameter of one egg. The accompanying table and diagram are self-explaining. They are based on a series of actual counts of eggs contained in a liquid quart measure, these counts fairly agreeing with each other and the theoretical value, and being extended by computation according to the law that solids increase as the third power of their diameters. Example : d =0.127", diameter of whitefish egg (determined). n =33,036, number of whitefish eggs per quart (actually counted). di =0.1406", diameter of shad egg (determined). Ui = Number of shad eggs per quart (sought) . d' : di^ = n, : n d^'n .•.n, = ^,or 0.127' : 0.1406' = ni : 33,036 „ 0.127^X33,036 0.1406' = 24,345, answer. METHOD OF MEASURING FISH EGGS. IOI3 Table for Finding Number of Fish Eggs op Given Diameter per Liquid Quart. Diame- ter. Number. Diame- ter. Number. Diame- ter. Number. Diame- ter. Number. Inch. Inch. Inch. Inch. 0.300 2.S06 0.230 5. 562 0. i6o 16.521 0. 090 92.826 2.S3I 5.635 16,83s 95.990 2.SS7 5. 709 17, 157 99. 297 2.583 S.78S 17.487 102,762 2. 609 5. 862 17.825 106, 390 0. 295 2.635 0.22s 5.941 0. ISS .8.172 0.08s no, 190 = .663 6.021 18,528 114, 172 2. 690 6. 102 18.894 118,346 2.718 6.18s 19. 270 122, 730 2. 746 6. 269 0. isi 19.65s 127,333 0. 290 2. 775 6,3SS 0. ISO 20.050 0,080 132, 170 2,804 6, 442 20.456 137. 251 2.833 6,531 20.874 142, 600 2,863 6,622 21.303 148.220 2,893 6,71s 21.744 154. 155 0.28s 2,923 0. 215 6,809 0. 145 22, 197 0.07S 160, 400 2.954 6,90s 22,662 166,995 2.985 7,002 23, 140 173,950 3.017 1 7. 102 23,633 181,300 3.050 1 7. 204 24, 140 189,070 0. 280 3.083 1 0. 210 7.307 0. 140 24.661 0.070 197, 290 3. 116 7.412 25.197 205,992 3, 150 7.S20 25.748 215, 204 3, 184 7.629 26.316 224,995 3,219 7. 74t 26.901 235,377 0.275 3. 254 0. 205 7.855 o. 135 27. S04 0. 065 246,410 3. 290 7.971 28.125 258,141 3.326 8.089 28.764 270.631 3,363 8,210 29. 422 283,936 3,400 0. 2or 8.333 30, loi 298.132 0.270 3,438 0. 200 8.459 0. 130 30,801 0.060 313.289 3,476 8.S87 31,523 329,490 3.51S 8.717 32.268 346.828 3,SSS 8.851 33,036 365,405 3. 595 8.987 33.829 385,331 0.26s 3.636 o. I9S 9,126 0, 125 34. 647 0.05s 406. 733 3.677 9, 268 35.492 429, 750 3.719 9,413 36.364 454. 539 3.762 9. S6l 37. 26s 481.270 3,806 9. 712 38, 198 510, 139 0. 260 3.850 0. 190 9.866 0. 120 39, 161 0.050 541,362 3.89s 10.023 40, 156 575, 173 3.940 10,184 41,186 611,893 3.986 10,348 42. 251 651. 776 4.033 io,si6 43,354 69s. 223 0. 2S5 4.081 0.18s 10.688 0. IIS 44. 494 O.04S 742,613 4. 129 10.863 45.676 794. 400 4,178 11.042 46.899 851. 128 4,228 11.225 48, 166 913.380 0. 251 4.279 II, 412 49.480 981.852 0.250 4.331 0.180 II, 603 0. no SO. 841 0.040 1.057.350 4.383 II. 799 52. 254 I. 140, 780 4, 436 11.999 53. 720 1.233, 250 4, 490 12. 203 55. 239 I. 335. 960 4,545 12, 412 56,817 I. 450, 406 0. 24s 4, 601 0. 17s 12,627 0. los 58.456 0.035 1.578.320 4.658 12,846 60. 159 1.721,630 4.716 13.069 61,925 1.883.020 4. 776 13.298 63,766 2,065, 130 4.83s 13.533 0. lol 65,680 2. 271,500 0.240 4.895 4.956 5.019 5.083 5, 148 0. 170 13.774 14,020 14, 272 14.529 14, 793 67, 670 69. 741 71.899 74, 146 76. 486 0.030 2,506,310 0. 23s III'. 5. 350 5. 419 5.490 0.16s IS. 064 IS. 341 15,625 15.916 16. 215 0.095 78,927 81,473 84,130 86. 904 89, 800 CON\'ERSION TABLE. inch 4 millimeters. millimeter 03937 inch. quart = S7 75 cubic inches. quart 9464 liter. liter -61 0234 cubic inches I liter = 1.0567 quarts. I pound = 0.4536 kilogram. I kilogram = 3.2046 pounds. Fahrenheit =9/5 centigrade ± 3 2 ' Centigrade =5/9 Fahrenheit ±32 IOI4 BULLETIN OF THE BUREAU OF FISHERIES. O/O/H. IM cftclmoU ofairlneh Portion of O/a^ram shoir/n^ method of findincf number of eqys per //quid ^uart 10,000 toiooo 3opoo Acooo 501,000 70)000 60,000 90000 loqpoo Directions: Find the line on the left margin corresponding to the given diameter; follow said line to the right until it intersects the curve; from this intersection proceed at right angles to the lower mar- ginal line of figures and there read the required number of eggs per quart. If diameter is given in millimeters multiply by 0.03937 to reduce to inches. LIBRfiRY OF CONGRESS 002 854 007 3 # 3R^P^ \\\\|»Sk'A00l^t HoUinger Corp. pH8.5