Acta Ichthyologica et Piscatoria 25(1): 57-70, doi: 10.3750/AIP1995.25.1.05
Morphometrics of the autumn and spring run populations of the river lamprey, Lampetra fluviatilis (Linnaeus,1758) from the Polish rivers
expand article infoJ. Kuszewski, A. Witkowski
Open Access
The plastic and meristic characters of the river lamprey were studied in 145 specimens of the autumn and spring run populations from the north-Polish rivers (the Grabowa, Drwęca, Wda, Parsęta). Among the examined lamprey populations entering the Polish rivers in autumn no essential differences in body proportions are observed. In comparison with autumn populations, the lampreys that start their spawning migration as late as spring differ more considerably with respect body proportions. Besides, they are characterised by more marked sexual dimorphism, which can be related to more advanced development of gonads.