Marine Biology

, Volume 63, Issue 1, pp 101–106 | Cite as

A density-gradient column for determining the specific gravity of fish eggs, with particular reference to eggs of the mackerel Scomber scombrus

  • S. H. Coombs


A new method is described for determining the specific gravity of fish eggs. The technique requires the preparation of a stable column of a continuously graded solution of sea-water salts such that a specimen introduced into the column settles at a level of known specific gravity, where it is in hydrostatic equilibrium with the fluid in the column. The method allows the simultaneous measurement of specific gravity of a number of specimens continuously throughout development and is suitable for use aboard a vessel at sea. Differences of specific gravity may be resolved to a precision of better than 4x10-5; as an example of use of the method, the specific gravity of eggs of the mackerel Scomber scombrus L. declined during development within the range 1.0205 to 1.0245; unfertilized eggs displayed a continuous increase of specific gravity.


Specific Gravity Simultaneous Measurement Continuous Increase Hydrostatic Equilibrium Stable Column 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. Alderdice, D. F. and C. R. Forrester: Some effects of salinity and temperature on early development and survival of the English sole (Parophrys vetulus). J. Fish. Res. Bd Can. 25, 495–521 (1968)Google Scholar
  2. Alderdice, D. F. and C. R. Forrester: Effects of salinity and temperature on embryonic development of the petrale sole (Eopsetta jordani). J. Fish. Res. Bd Can 28, 727–744 (1971)Google Scholar
  3. Anonymous: Column grades Teflon density. Qual. Assurance, Wheaton, Ill. Feb., 38–39 (1967)Google Scholar
  4. Blaxter, J. H. S. and K. F. Ehrlich: Changes in behaviour during starvation of herring and plaice larvae. In: The early life history of fish, pp 575–588. Ed. by J. H. Blaxter. New York: Springer-Verlag 1974Google Scholar
  5. Coombs, S. H., R. K. Pipe and C. E. Mitchell: The vertical distribution of eggs and larvae of blue whiting (Micromesistius poutassou) and mackerel (Scomber scombrus) in the eastern North Atlantic and North Sea. Rapp. P.-v. Réun. Cons. perm. int. Explor. Mer. (In press)Google Scholar
  6. Cunningham, J. T.: Studies on the reproduction and development of teleostean fishes occurring in the neighbourhood of Plymouth: Scomber. J. mar. biol. Ass. U.K. 1, 10–54 (1889)Google Scholar
  7. Franz, V.: Untersuchungen über das spezifische Gewicht der planktonischen Fischeier. Wiss Meeresunters. (Abt. Helgoland) NF 9, 179–196 (1910)Google Scholar
  8. Holliday, F. G. T. and M. P. Jones: Some effects of salinity on the developing eggs and larvae of the plaice (Pleuronectes platessa). J. mar. biol. Ass. U.K. 47, 39–48 (1967)Google Scholar
  9. Iversen, S. A.: Spawning egg production and stock size of mackerel (Scomber scombrus L.) in the North Sea 1968–1975. Int. Counc. Explor. Sea Comm. Meet. (Pelagic Fish: Northern) H 17, 1–19 (1977). (Mimeo)Google Scholar
  10. Jacobsen, J. P. and A. C. Johansen: Remarks on the changes in specific gravity of pelagic fish eggs and the transportation of same in Danish waters. Meddr Kommn Havunders. (Serie: Fiskeri III) 2, 1–24 (1908)Google Scholar
  11. Kändler, R. and E. O. Tan: Investigations on the osmoregulation in pelagic eggs of gadoid and flatfishes in the Baltic. Part I, Changes in volume and specific gravity at different salinities. Int. Counc. Explor. Sea Comm. Meet. (Baltic-Belt Seas) 43, 1–5 (1965). (Mineo)Google Scholar
  12. Lockwood, S. J., J. H. Nichols and S. H. Coombs: The development rate of mackerel (Scomber scombrus L.) eggs over a range of temperatures. Int. Counc. Explor. Sea. Comm. Meet. (Pelagic Fish: South) J 13, 1–8 (1977). (Mimeo)Google Scholar
  13. Løvtrup, S.: Determination of density of amoebae by means of a starch density gradient. C.r. Trav. Lab. Carlsberg (Ser. chim.) 27, 137–144 (1950)Google Scholar
  14. Margalef, R.: Velocidad de sedimentación de organismos pasivos de fitoplancton. Investigación pesq. 18, 3–8 (1961)Google Scholar
  15. Moore, J. P.: Report on mackerel investigations in 1897. Rep. U.S. Commnr Fish. 1898 (24), Appendix 1–22 (1899)Google Scholar
  16. Pertoft, H. and T. C. Laurent: The use of gradients of colloidal silica for the separation of cells and subcellular particles. In: Modern separation methods of macromolecules and particles, Vol. 2. pp 71–90. Ed. by T. Gerritsen. New York: Wiley Interscience 1969Google Scholar
  17. Price, C. A., J. M. Onge-Burns, J. B. Colton, Jr. and J. E. Joyce: Automatic sorting of zooplankton by isopycnic sedimentation in gradients of silica: performance of a “rho spectrometer”. Mar. Biol. 42, 225–231 (1977)Google Scholar
  18. Remotti, E.: Variazioni di peso specifico nelle uova galleggianti dei teleostei durante lo sviluppo. Memorie R. Com. talassogr. ital. 80, 1–42 (1921)Google Scholar
  19. Salzen, E. A.: The density of the eggs of Calanus finmarchicus. J. mar. biol. Ass. U.K. 35, 549–554 (1956)Google Scholar
  20. Sette, O. E.: Biology of the Atlantic mackerel (Scomber scombrus) of North America. Part 1: Early life history, including the growth, drift and mortality of egg and larval populations. Fishery Bull. Fish Wildl. Serv. U.S 50 (38), 149–235 (1943)Google Scholar
  21. Solemdal, P.: The effect of salinity on buoyancy, size and development of flounder eggs. Sarsia 29, 431–442 (1967)Google Scholar
  22. Solemdal, P.: Prespawning flounders transferred to different salinities and the effects on their eggs. Vie Milieu 1 (Suppl. 22), 409–423 (1971)Google Scholar
  23. Sundnes, G., H. Leivestad and O. Iversen: Buoyancy determination of eggs from the cod (Gadus morhua L.). J. Cons. perm. int. Explor. Mer 29, 249–252 (1965)Google Scholar
  24. Tamura, O.: The specific gravity of mature eggs of cod (Gadus macrocephalus). In: Special Publication of the Japan Sea Regional Fisheries Research Laboratory on the Third Anniversary of its Founding, pp 271–275. Niigata, Japan: Japan Sea Regional Fisheries Research Laboratory 1952. [Transl. Ser. Fish. Res. Bd Can. No. 401 (1962)]Google Scholar

Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • S. H. Coombs
    • 1
  1. 1.Institute for Marine Environmental ResearchNatural Environment Research CouncilPlymouthEngland

Personalised recommendations