MONITORING AND ANALYSIS OF THE SEASONAL VARIABILITY OF THE EPIFAUNA OF THE PHYLUM MOLLUSCA ASSOCIATED WITH THE PHYTAL OF THE TIDAL POOLS OF THE SANDSTONE REEF OF PIEDADE BEACH (PE)

Abstract

The malacofauna associated with the phytal ecosystem of the coastal reef of Piedade beach, Jaboatão dos Guararapes, PE, was studied.  The phytal is a biocenosis with its own characteristics and the algae is the substrate that serves as a home, shelter and/or food for the associated fauna. Tide pools were selected at three collection points on the coastal reef that were sampled every two months during the period from August 2022 to June 2023. The collections carried out in October 2022, December 2022 and February 2023 were considered dry period; the collections carried out in August 2022, April 2023 and June 2023 of the rainy season. In the laboratory, the fronds were washed, filtered in a sieve with a 500 μm mesh mesh, the retained animals were fixed with 5% saline formaldehyde, later identified and quantified under a stereoscopic microscope. The environmental parameters water temperature, air temperature and relative humidity showed little variation between the dry and rainy periods. The wind speed had values with significant variation, with a maximum of 21.95 m/s in October 2022 and a minimum of 1.6 m/s in February and April 2023. Rainfall values varied significantly between the months of the dry season and those of the rainy season, with a maximum value of 481.95mm in June 2023 and a minimum of 42.6mm in December. A total of 3038 individuals were collected, totaling 38 species collected, representing 21 families of Gastropoda.  It was considered a typical species in the study area:  Eulithidium affine because it had a higher frequency of occurrence. Regarding seasonality, there was equity between the two seasons; The dry period presented species richness, with 31 species recorded. The rainy season presented the richness of species, with the occurrence of 29 species.  It was concluded that there is no significant seasonal variation in the occurrence of species considered constant, with occurrence of E. affine throughout the year and other species considered constant. The low diversity, when compared to previous studies in the area, indicates a trend of impact on biocenosis.

DOI: https://doi.org/10.56238/sevened2025.008-034