Breeding patterns of single-nest rotunda

The reproduction of B. plicatilis can be either sexual (called mictic reproduction) or asexual (amictic or parthenogenetic reproduction). Only the latter is adopted for rotifer mass culture due to its faster rate. In the amictic reproduction there is no distinct larval stage: the young that hatch from an egg already looks like an adult and the offspring are clones genetically identical to their mothers, i.e. all newly born rotifers are diploid females. Such multiplication can go on for months in a population kept in proper rearing conditions. Most rotifers are multivoltine (sometimes more than 20 generations per year. Depending on environmental conditions, each female may produce about 20 amictic eggs. When conditions become less favourable (return of either the winter period or the dry season or overcrowded population), mictic female appear that produce haploid eggs developing into males, sexual reproduction occurs with the mictic females and thickwalled resting diapausing eggs (mictic resting eggs) are produced that can survive anaeroby, frost and desiccation. After weeks or months, when the conditions restore, resting eggs develop into parthenogenetic amictic females again.

Propagation of the folded arm-tail rotifers can be either sexual (called hybrid reproduction) or asexual reproduction (non-mixed parthenogenesis). Due to its faster reproduction rate, asexual reproduction is suitable for large-scale culture of rotifers. There is no obvious larval stage in non-hybrid reproduction: the pups hatched from the eggs already look like an adult, and the offspring are genetically identical clones to the mother. That is, all neonatal rotifers are diploid females. Maintain proper population conservation and breeding conditions, and such reproduction can last for several months. Most rotifers are polymorphic (sometimes more than 20 generations a year). Depending on the environmental conditions, each female can produce about 20 non-mixed eggs. When the environment becomes less favorable (winter or dry period or rotifer density is too high), the hybrid female produces haploid eggs, and after developing into males, the hybrid female undergoes sexual reproduction, producing thick-walled dormant diapause eggs (mixed dormant eggs) that can survive anaerobic, frosted, and dry conditions. After a few weeks or months, when conditions return, the dormant eggs develop into parthenogenesis.