Banca de QUALIFICAÇÃO: Tiago da Rocha Pedra

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : Tiago da Rocha Pedra
DATA : 20/03/2026
HORA: 11:00
LOCAL: Online
TÍTULO:

How Does Water Stress Affect the Morphology and Reproduction of Zooplankton? A Desiccation Study in the Northern Pantanal

PALAVRAS-CHAVES:

Aquatic ecosystems, Dormancy, Ecological resilience, Hatching.

PÁGINAS: 60
GRANDE ÁREA: Ciências Biológicas
ÁREA: Ecologia
SUBÁREA: Ecologia Teórica
RESUMO:

The Pantanal, one of the largest floodplains in the world, exhibits an ecological dynamic strongly influenced by its hydrological regime, which regulates the biodiversity and functionality of its aquatic ecosystems. In recent years, climate change has intensified drought periods, altered hydrological connectivity and directly impacting aquatic communities such as zooplankton. This study aimed to understand how water stress affects the morphology and reproduction of zooplankton through the hatching of dormant eggs from sediments in the Northern Pantanal, within the municipality of Cáceres (MT), Brazil. Seven sampling points with different degrees of connectivity to the Paraguay River were analyzed, representing permanent and temporary bays and lagoons. Limnological variables (dissolved oxygen, pH, conductivity, temperature, and transparency) were recorded in situ, and sediment was collected using a core sampler for incubation experiments in microcosms under controlled temperature and photoperiod conditions. Two experimental treatments were conducted: the first involved immediate rehydration after desiccation, and the second rehydration after five months of dry and dark storage. The hatching and succession of the communities were monitored for 60 days, with taxonomic identification and morphofunctional analysis of the emerging organisms. Statistical analyses, including PERMANOVA, PCoA, and rank-abundance curves, revealed significant differences in the composition and temporal dynamics of the communities between experiments. The immediate rehydration treatment showed high temporal variation and initial dominance of opportunistic species such as rotifers from the families Lecanidae and Brachionidae, followed by cladocerans (Alona, Macrothrix, Ceriodaphnia) and copepods (Calanoida). Conversely, the long desiccation treatment exhibited more stable and diversified communities from the earliest weeks, indicating that storage time influences functional structure and hatching rates. A total of 22 taxa were identified, distributed among 11 families, evidencing the representativeness of the main zooplankton groups (Rotifera, Cladocera, and Copepoda) typical of lentic and floodplain environments. The results confirm that the dormant egg bank functions as an important mechanism of ecological resilience, enabling rapid community recovery after prolonged drought periods. The ecological succession observed in the microcosms reproduces the natural cycle of the Pantanal, with alternation between small, highly plastic species and larger, more specialized organisms as the system stabilizes. Rehydration time proved to be a key factor in shaping functional structure and diversity, surpassing the influence of habitat type. These findings reinforce the importance of flood and drought pulses as drivers of biological diversity and highlight the need to preserve the Pantanal’s natural hydrological regime in the face of climate change. Thus, this study contributes to the understanding of ecological processes of persistence and succession in zooplankton communities, offering valuable insights for conservation and sustainable management strategies of Neotropical wetlands.

MEMBROS DA BANCA:
Presidente - 118181001 - WILKINSON LOPES LAZARO
Interno - 118188003 - ERNANDES SOBREIRA OLIVEIRA JUNIOR
Externa à Instituição - THAÍS XAVIER DE MELO - UFMT