Temporal variation in abundance and population dynamics of the crab Hepatus pudibundus (Herbst, 1785) (Crustacea, Decapoda, Brachyura) over a 30 year interval, 1995-2025, in Ubatuba Bay, São Paulo, Brazil

• Grant number: 25/17152-5
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2025
• End date: February 28, 2027
• Field of knowledge: Biological Sciences - Zoology - Morphology of Recent Groups
• Principal Investigator: Rogério Caetano da Costa
• Grantee: Gabriel Matos Fortes Dioro
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated research grant: 18/13685-5 - Integrative analysis of the Brazilian fauna of decapod crustaceans: taxonomy, phylogenetic systematics, spermiotaxonomy, morphology of post-embryonic development, ecology and conservation, AP.BTA.TEM

Abstract

The species Hepatus pudibundus, a benthic crab of ecological relevance in the South Atlantic, plays critical roles in its environment. Environmental changes, such as ocean warming and alterations in sediment composition, increase its vulnerability, restricting habitats and compromising its ecological functions. Thus, the present study aims to analyze the abundance, size, growth rate, mortality (natural and fishing), and sexual maturity of the marine crab H. pudibundus in the region of Ubatuba, northern coast of the State of São Paulo, considering environmental factors over a temporal variation of 30 years. For this purpose, trawl data from 1995 to 2025 were collected and grouped into 12-month periods, namely: 1stP (1995-1996), 2ndP (1998), 3rdP (1999), 4thP (2013-2014), 5thP (2016-2017), 6thP (2021-2022), and 7thP (2024-2025). Throughout the entire sampling period, data on temperature, salinity, and sediment were collected, and data related to the El Niño Southern Oscillation will be obtained from online databases. The individuals collected were separated by sex and measured for carapace width, total weight, and gonadal stage. Based on the results obtained, statistical analyses appropriate to each proposed objective will be carried out to compare their distribution and abundance, relating them to environmental factors and fishing pressures during the sampled years.