Superior life history traits of Micromoina arboricola in a humic over a non-humic environment

Micromoina arboricola, one of the smallest moinids on record, is currently known from a single tree hole in a tropical forest, containing a small volume of humic water, in quasi absolute darkness. We test whether it has been refuted to this environment by superior competitors, or whether it is genuinely adapted to this life space by culturing it in its native environment, and in a clear water environment supplemented with algal food, yeast and fermented fish ration. Only maturation time is similar between both treatments. Total offspring, number of clutches, average clutch size and longevity are higher in the humic treatment. Population growth is initially higher in the clearwater treatment, but then collapses. In the humic treatment there is a steady ascent towards a stable plateau. We conclude that the species is better adapted to its microcosm than to a ‘normal’ aquatic biotope.