Pycnogonida associado à macroalgas nos recifes areníticos nas praias da Pina e Boa Viagem, Pernambuco - Brasil

Abstract

Picnogonids are benthic or pelagic marine arthropods, with approximately 1340 recent species considered valid, which are distributed globally from tropical to polar seas. They are generally called "sea spiders" because of their superficial resemblance to real terrestrial spiders. Little information is found on the fauna of pycnogonids off the coast of Brazil, where the group has been little and sporadically addressed in the literature. In this sense, the objective of this work was to carry out the identification of specimens associated with macroalgae collected on the beaches of Pina and Boa Viagem, south coast of the state of Pernambuco. At Pina beach the collection was carried out from May to July / 2018 (rainy season) and September to November / 2018 (dry season) and in Boa Viagem from January to March / 2019 (dry season) and May to July / 2019 (rainy season). In both beaches, collections were carried out manually in the mesolitoral region during low tide. For taxonomic identification of pycnogonids, this was carried out down to the species level, with the aid of a stereomicroscope, using specialized bibliography. A total of 258 specimens were counted, distributed in 03 families, 03 genera and 08 species. The species Anoplodactylus ganchiformis Lucena and Christoffersen, 2018 was considered very frequent (100%), standing out in the rainy season in both investigated beaches. At Pina beach, the species that contributed most in terms of relative abundance were: Anoplodactylus stictus Marcus, 1940 (57.1%) in the dry season and A. ganchiformis (47.4%) in the rainy season. The species A. stictus also showed a high contribution in terms of relative abundance on the Boa Viagem beach, in the dry (42.4%) and rainy (57.8%) periods. The diversity indexes were also checked and it was noted that the month of November was the only one that assumed a zero index. The species Anoplodactylus batangensis (Helfer, 1938) and Anoplodactylus evelinae Marcus, 1940 had their records expanded for the beaches in question. The species A. stictus had its record expanded to the state of Pernambuco and the species Anoplodactylus ricardoi Lucena and Christoffersen, 2018 and A. ganchiformis had their first records for Pernambuco and the second for the Northeast. It is hoped that these records can contribute and encourage the search for more work, in order to obtain a better understanding of the systematics and distribution of Pycnogonida, since little information is found about this fauna.