Period-dependent sex-biased movement in a polygamous stream fish (**Cottus perifretum** Freyhof, Kottelat & Nolte, 2005 - Actinopterygii, Cottidae) with male parental care
Faculty of Sciences. Biology
Hydrobiologia. - The Hague
, p. 195-204
University of Antwerp
Inter-sexual differences in reproductive behaviours such as mate choice or parental care may cause sex-bias in movement distances. While this relationship has been extensively studied in birds and mammals, little is known regarding fishes. Fifty-four bullhead (Cottus perifretum), polygamous stream fish with male nest holding, were tracked by means of a portable antenna in a 2,500 m stream reach. Movement was measured at two time scales: monthly movement distance and long-term movement range. Bullhead moved furthest in February and May. In these months, movement distances diversified between the sexes. Females moved significantly furthest in February. This may be related to female mate-choice at the beginning of the reproductive period. In May, at the end of the reproductive period, males moved significantly longer distances. It is speculated that males shift to resource-richer habitats after the starvation during parental care. In general, smaller individuals moved longer distances per month. Long-term movement range did not differ between the sexes but varied considerably between individuals ranging from 1 to 1,111 m. It is concluded that movement studies should encompass an annual time scale as well as a more precise monthly time scale to present an accurate description of sex-biased movement in (annual spawning) fish.