Substrate type and pond morphometry shape zooplankton emergence from dormant egg banks in semiarid temporary ponds

Temporary ponds in semiarid regions are strongly influenced by hydrological variability, yet the role of substrate type and pond morphometry in structuring zooplankton emergence from dormant egg banks remains poorly understood. We investigated how contrasting substrates, sandstone, granite, and clay, influence hatching dynamics, taxonomic composition, and diversity patterns of zooplankton emerging from sediment egg banks in temporary ponds of northeastern Brazil. We also evaluated whether pond morphometric attributes were associated with compositional differences among emerging communities. A total of 60 taxa emerged during the experiment, with the highest richness recorded in sandstone ponds (43 taxa), followed by granite (35 taxa), and clay ponds (27 taxa). Early emergence differed among substrates, with sandstone ponds showing the highest richness within the first 48 h, whereas clay ponds showed a more restricted early hatching response. The total abundance of hatched organisms did not differ significantly among substrate types. In contrast, taxonomic composition differed significantly among substrates, with Cyclopoida nauplii and rotifers of the family Brachionidae contributing most to compositional dissimilarity. β diversity also differed significantly among substrate types, indicating compositional turnover among pond types. Among the morphometric attributes evaluated, pond depth was the only variable significantly associated with β diversity, indicating that deeper ponds supported greater compositional differentiation among emerging zooplankton communities. Diversity based on Hill numbers tended to be higher in sandstone ponds, particularly for q = 0 and q = 1, while greater overlap among substrate types was observed for q = 2. Overall, substrate type and pond morphometry jointly contributed to the reassembly and diversity of zooplankton communities emerging from dormant egg banks in semiarid temporary ponds.