Epipelagic copepods of Gorgona Island, Tropical Eastern Pacific: Taxonomy, size range, and sexual proportion

Abstract

Copepod species present the greatest diversity of marine zooplankton in tropical systems worldwide. This study aimed to increase knowledge in biodiversity by providing a comprehensive species checklist, distribution, size range, and sexual proportion of copepods associated with the epipelagic environment around Gorgona Island, Eastern Tropical Pacific. Zooplankton samples were obtained in oblique tows from 40 m depth to the surface, using a bongo net with 300μm mesh size from a total of six sampling trips between 2010 and 2016. A total of 73 copepod species belonging to 22 families associated with the epipelagic environment of Gorgona Island were recorded. Seasonal differences in sexual proportion were observed for 32 species. The assemblage was composed mainly of small-sized families, such as Corycaeidae, Euterpinidae, Oncaeidae, and Paracalanidae. The species with greatest relative abundance were Euterpina acutifrons, Subeucalanus pileatus, Ditrichocorycaeus andrewsi, Oncaea clevei, and Paracalanus parvus, which together comprised 61.8% of total copepod relative abundance throughout the study. Non-parametric estimates of species richness for the present study suggested a sampling efficiency above 90%. This study represents the first taxonomic record of epipelagic copepods for Gorgona Island, generating 41 new records for the Colombian Pacific and it increases the distribution of Bestiolina similis, Lubbockia marukawai, Oithona brevicornis and Sapphirina sinuicauda in the Eastern Tropical Pacific, which until now, were registered only in tropical areas of the Central Pacific and Indian Ocean, and in temperate areas of the Northeast Pacific.