Distribución y abundancia de macroinvertebrados marinos asociados a la zona intermareal rocosa de San Mateo, desde diciembre 2021 a junio 2022, Manta-Ecuador.

Abstract

The communities of marine macroinvertebrates in the parish of San Mateo, located in the city of Manta, province of Manabí, were studied. The objective of this work was to determine the distribution and abundance of macroinvertebrates in the rocky intertidal zone of San Mateo from December 2021 to June 2022. Following the methodology of Miloslavich & Carbonini, (2010), linear transects of 50 meters perpendicular to the beach with 9 stations. The monitoring was carried out on a weekly basis. The distribution, abundance, diversity, and equitability of macroinvertebrates among the intertidal zone (supralittoral, mesolittoral and infralittoral) were analyzed. The absolute abundance was 6,045 individuals, from 25 species of macroinvertebrates in the rocky coastline belonging to four phylum: Mollusca, Echinodermata, Arthopoda and Annelida. The most representative species were molluscs, including Siphonaria maura (30.79%) and Arca zebra (16.01%). The echinoderms were present: the species Ophiocoma alexandri (5.31%) and Echinometra vanbrunti (4.68%), and the Arthropods Tetraclita sp (4.30%) and Pachygrapsus marmoratus (3.16%). The dominance in the intertidal zone was low (0.13 ±0.06), a mean diversity of 3.06 ±0.66 and a high evenness (0.88 ± 0.06). Through the nMDS analysis, it was evidenced that the zones with the greatest similarity were the mesolittoral zone and the infralittoral zone, presenting a high homogeneity between the species. There was no direct correlation between the environmental variables and the physicochemical parameters in this study.