Life history characteristics of Macrothrix rosea (Jurine, 1820) (Cladocera, Macrothricidae) in laboratory conditions

Our knowledge of the life history characters of medium-size cladoceran species remains quite restricted. In order to address this issue, the present study examined the life history of a medium-size species, Macrothrix rosea (Cladocera, Macrothricidae), in laboratory conditions. Neonates produced by previously acclimatized parthenogenetic females were cultured at 25 ± 1 °C to investigate their growth rate, fecundity, and development. Our results show that individuals of M. rosea underwent three juvenile instar stages and 10 adult instars at 25 °C, with an average life span 33 ± 6.33 days. The average total number of eggs produced per individual was 121.04, with a maximum of 151. Individuals in the seventh instar stage (fourth adult instar) produced the largest number of offspring. The growth of body length showed a logarithmic pattern, whereas the cumulative fecundity and population growth appeared to be logistic. Furthermore, we compared the growth and mean fecundity from the birth to the first adult instar at three different temperatures (i.e., 15, 20, and 25 °C). The growth rate of body length was slower at lower temperatures than at higher temperatures, while the mean fecundity was higher and the time needed for developing to adult was longer at lower temperatures. In conjunction with previous studies, our data suggest several shared life history characteristics among cladocerans.