Abstract
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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Literature Cited
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)
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)
Anonymous: Column grades Teflon density. Qual. Assurance, Wheaton, Ill. Feb., 38–39 (1967)
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 1974
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)
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)
Franz, V.: Untersuchungen über das spezifische Gewicht der planktonischen Fischeier. Wiss Meeresunters. (Abt. Helgoland) NF 9, 179–196 (1910)
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)
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)
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)
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)
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)
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)
Margalef, R.: Velocidad de sedimentación de organismos pasivos de fitoplancton. Investigación pesq. 18, 3–8 (1961)
Moore, J. P.: Report on mackerel investigations in 1897. Rep. U.S. Commnr Fish. 1898 (24), Appendix 1–22 (1899)
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 1969
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)
Remotti, E.: Variazioni di peso specifico nelle uova galleggianti dei teleostei durante lo sviluppo. Memorie R. Com. talassogr. ital. 80, 1–42 (1921)
Salzen, E. A.: The density of the eggs of Calanus finmarchicus. J. mar. biol. Ass. U.K. 35, 549–554 (1956)
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)
Solemdal, P.: The effect of salinity on buoyancy, size and development of flounder eggs. Sarsia 29, 431–442 (1967)
Solemdal, P.: Prespawning flounders transferred to different salinities and the effects on their eggs. Vie Milieu 1 (Suppl. 22), 409–423 (1971)
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)
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)]
Author information
Authors and Affiliations
Additional information
Communicated by J. Mauchline, Oban
Rights and permissions
About this article
Cite this article
Coombs, S.H. A density-gradient column for determining the specific gravity of fish eggs, with particular reference to eggs of the mackerel Scomber scombrus . Mar. Biol. 63, 101–106 (1981). https://doi.org/10.1007/BF00394667
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00394667