Banca de DEFESA: VICTÓRIA STEVENSON MARTINS NUNES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : VICTÓRIA STEVENSON MARTINS NUNES
DATE: 02/07/2026
TIME: 13:00
LOCAL: Google Meet (convidados devem solicitar link completo à discente)
TITLE:

MORPHOECOLOGICAL ASPECTS OF SEA CUCUMBERS: ENVIRONMENTAL INFLUENCE, ONTOGENY, AND HABITAT SELECTION

KEY WORDS:

Sea cucumber; Morphometrics; Taxonomy; Ontogeny; Intraspecific variation.   

PAGES: 71
BIG AREA: Ciências Biológicas
AREA: Zoologia
SUBÁREA: Morfologia dos Grupos Recentes
SUMMARY:

Sea cucumbers play essential ecological roles in marine benthic ecosystems by contributing to nutrient cycling, organic matter processing, and sediment quality maintenance. However, the factors influencing their morphology, development, and distribution remain poorly understood, particularly in tropical environments. This study investigated morphoecological aspects of sea cucumbers along the northeastern coast of Brazil through an integrated approach encompassing environmental influences on morphology, ontogenetic development, and habitat selection during early life stages. In the first chapter, the relationship between environmental variables and calcareous ossicle morphology was examined in six species distributed across four coastal localities. The results demonstrated that ossicle morphology responds to environmental gradients, particularly pH, salinity, and total dissolved solids, highlighting the importance of phenotypic plasticity in adaptation to distinct environmental conditions. The second chapter investigated morphological and morphometric changes associated with the development of Stolus cognatus. Progressive modifications were observed in both external and internal diagnostic structures, including ossicles, tube feet, tentacles, respiratory trees, and gonads, allowing the recognition of distinct ontogenetic morphotypes and improving the taxonomic resolution of the species. The third chapter evaluated spatial and seasonal diversity patterns of post-larval sea cucumbers and their associations with substrate types and environmental variables. All recorded individuals occurred exclusively within macroalgal beds, confirming the importance of these habitats as nursery grounds. Effective species richness was positively associated with pH and negatively affected by the rainy season, indicating high sensitivity of early life stages to environmental variability. Collectively, the findings demonstrate that the structure and persistence of sea cucumber populations are shaped by the interaction among environmental factors, ontogenetic processes, and the availability of suitable recruitment habitats. This study advances current knowledge of the ecology, morphology, and life history of tropical sea cucumbers and provides valuable information for taxonomic research, ecological assessments, and conservation strategies in coastal ecosystems.

COMMITTEE MEMBERS:
Externo à Instituição - RUDÁ AMORIM LUCENA - UFPB
Presidente - 1545394 - FULVIO AURELIO DE MORAIS FREIRE
Externa à Instituição - RENATA APARECIDA DOS SANTOS ALITTO - UNICAMP
Externa ao Programa - 347010 - ROSANGELA GONDIM D OLIVEIRA - nullExterna à Instituição - THELMA LÚCIA PEREIRA DIAS - UEPB