Skip to main content
SLU publication database (SLUpub)

Research article2018Peer reviewedOpen access

Population specific sperm production in European flounder Platichthys flesus: Adaptation to salinity at spawning

Nissling, Anders; Larsson, Roger


Marine teleosts inhabiting the brackish Baltic Sea have adapted to the less saline water with activation of spermatozoa at low salinity hypo-osmotic conditions but with shorter longevity and lower swimming speed that affect the fertilization capacity. Aiming to elucidate if the fertilization capacity may be maintained by increasing the number of spermatozoa produced, testis size for the euryhaline flounder Platichthys flesus with external fertilization was assessed along a salinity gradient; with spawning at a salinity of c. 7, 10-18 and 30-35. Fulton's condition factor K = 0.881 +/- 0.085 (mean +/- S.D.), 0.833 +/- 0.096 and 0.851 +/- 0.086, for fish spawning at salinities of c. 7, 10-18 and 30-35, respectively, with no difference between areas, i.e. analysed fish were in similar nutritional condition. A general linear model, with testes dry mass as the dependent variable and somatic mass as covariate resulted in a significant difference between areas-populations with larger testes for P. flesus spawning at a salinity of c. 7 but no difference between fish spawning at a salinity of 10-18 and 30-35. The result suggests that adaptation by increasing the number of spermatozoa produced may be a key mechanism for marine teleosts spawning in areas with low salinities to sustain the fertilization capacity as shown here for the euryhaline P. flesus.


adaptation; flounder; population specific; salinity; sperm production; testes size

Published in

Journal of Fish Biology
2018, Volume: 93, number: 1, pages: 47-52 Publisher: WILEY

    UKÄ Subject classification

    Fish and Aquacultural Science

    Publication identifier


    Permanent link to this page (URI)