Results of comparative growing test of all-female and bisexual population in two-year-old common carp (Cyprinus carpio L.)

The aim of this study was to verify whetherall-female carp populations grow faster thanbisexual ones. All-female mirror and scalypopulations were obtained by crossingmasculinizated females (neomales) of Northernmirror carp (M72) with regular females of M72and scaly Ropsa carp (ROP) purebreds,respectively. All-female and bisexual progenyof both mirror and scaly carps were rearedseparately for one year. However, controlgroups of a distinct phenotype of scalinesswere put in ponds with tested fish to make anadjustment for fish weight, which could becaused by environmental influence. Nodifferences were found after eight weeks ofrearing between all-female and bisexualpopulations, but, all-female mirror carppopulation (M72) gained 29.7% more weight(P < 0.0001) by the end of the first year thanthe bisexual (68.5 g ± 15.8 against 52.8 g± 13.9; mean ± S.D., respectively).Before beginning the second growing season,each group was marked and stocked together intriplicate ponds. Corrected weight after secondgrowing season (P < 0.0062) was 9.9% higher inall-female mirror carps (395.9 g ± 98.6)compared to the bisexual (360.2 g ± 89.0).No significant differences were found incorrected weights between scaly all-female andbisexual crossbreds (522.4 g ± 102.4 and518.3 g ± 95.8, respectively). Nodifferences in survival of all-female andbisexual populations were observed.