Distribuição da comunidade de peixes recifais em relação à complexidade estrutural bentônica da Praia do Paiva - PE

Abstract

The reef environments are considered biodiversity hotspots and one of the most producing biological structures on Earth housing a large number of species of marine fish. In reefs, ichthyofauna is strongly associated with substrate complexity and abiotic characteristics, and it is essential to understand these to understand the functioning of ecosystems and ensure their conservation. In this sense, the objective of this study was to evaluate the taxocenose of recifal fish from Paiva beach, relating to the benthic environmental complexity of the environment. The collections were performed with underwater visual senses in linear transects at four sample sites on Paiva Beach, from December 2017 to November 2018. The fish were identified, classified according to conservation status to IUCN and its trophic category. As physical characteristics of the substrate, the height, depth and roughness of the substrate were measured. The analysis of the benthic composition of the substrate was made by the CPCe program from underwater photographs. Ecological descriptors (richness, abundance, diversity, horseriding and dominance) were analyzed. Spearman's correlation was obtained between abiotic and biotic parameters in the distribution of the ichthyophanistic community. A total of 2,314 individuals covering 36 species and 20 families were observed, where the Haemulidae family had the highest richness (8). Regarding The IUCN, the species Anisotremus surinamensis, Halichoeres brasiliensis and Sparissoma axilari were shown to be Deficient Data and Haemulon squamipinna and Lutjanus alexandrei as Unevaluated. The most abundant species were Stegastes fuscus (567) and Abudefduf saxatilis (427), which together comprised 43% of all species visualized. Point 3 stood out with the highest diversity of benthic composition, where all components were observed, higher mean roughness (76.8 cm) and substrate height (0.72 cm). In ecological descriptors, the diversity indices were higher in points 3 (H = 2.454) and 4 (H = 2.598) and horseriding (J = 0.7365 and J = 0.7717 respectively), and these points showed the lowest dominance indices (D =1156 and D = 0.1128 respectively). Point 3 was also the site with the highest concentration in both the number of individuals and in number of species. The substrate height had correlations with sampling points (rS=0.33), number of individuals (rS=0.3630), A. saxatilis (rS =0.3290) and A. surinamensis (rS =0.3555). Where the latter presented correlation with roughness (rS=0.2901). Stegastes fuscus was correlated with the sampling points (rS=0.312). Omnivores (568 individuals) and territorialist herbivores (567 individuals) were the most abundant trophic categories, however, feeders of moving invertebrates was the category with the highest species richness (18). In the distribution of trophic categories, points 3 and 4 stood out presenting the greatest balance. Environmental complexity has positively influenced the structure of the fish community as well as increased biodiversity. The roughness, height and composition of the substrate as well as the dominance of species, were more relevant to the description of environmental complexity. Due to the ecological and economic importance of the real environments, understanding the functioning of these ecosystems provides a basis for conservation and sustainable management.