Life finds a way: Hatching dynamics of zooplankton dormant stages in intermittent wetlands from the Brazilian tropical semiarid

Abstract

Hatching patterns of dormant stages are key to maintain zooplankton populations and to wetland functioning in drylands. However, the hatching dynamics of zooplankton dormant stages may vary across climate zones, and the knowledge of temporal hatching patterns of wetland zooplankton is incipient for tropical drylands in South America. With an ex-situ experiment, we assessed the temporal patterns in community structure of zooplankton hatchlings in the sediment of intermittent wetlands of the Brazilian tropical semiarid. Hatchlings were collected every two days in the laboratory over a 28-day hydration period. Hatchling abundance and richness peaked on the middle-to-late phase (third and fourth weeks), and composition showed a weekly variation over the hydration period. While large Branchiopoda and Moina sp. (Cladocera) predominated in the early phase (until the second week), most taxa of Ostracoda, Rotifera and Cladocera predominated in the middle-to-late phase of the experiment (third and fourth weeks after hydration). We found that the hatching patterns of zooplankton dormant stages in intermittent wetlands from the Brazilian semiarid convey marked short-term dynamics after hydration cues. This is useful to understand the zooplankton egg-bank hatching dynamics in tropical-dryland wetlands, which are expected to be under strong hydric stress in the future.