Deposition season and hatching patterns of resting eggs in Mixodiaptomus kupelwieseri (Crustacea: Copepoda)

We observed differences in resting eggs production in different seasons in Mixodiaptomus kupelwieseri from three temporary ponds and one permanent lake in the Italian Apennines. Hatching patterns of resting eggs produced in different seasons were evaluated under different laboratory incubation conditions (constantly kept in water and subject to one or two months of desiccation). The number of eggs hatching after incubation in dry conditions was too low to be used for quantitative analysis. Resting eggs from most populations and sampling seasons had a five-month refractory period. After that period, eggs produced in the fall hatched within a few days, while those produced in the spring kept hatching over a period of several weeks. No difference was found between hatching patterns of resting eggs produced in the permanent lake (only in the fall) and those produced in the same season in temporary ponds. Differences in genetic structure were found among populations but not between spring and fall females of the only population analyzed in both seasons.