New records of gelatinous zooplankton from an oceanic island in the Eastern Tropical Pacific

Abstract

Gelatinous zooplankton are an abundant and diverse group of animals in the pelagic environment. However, knowledge of species diversity and spatial distributions, as well as their ecological role, is scarce. We present information of epi- and mesopelagic gelatinous zooplankton recorded by the ‘DeepSee’ submersible between 2006 and 2012 at Isla del Coco (Cocos Island), Costa Rica, an oceanic island in the Eastern Tropical Pacific. Two species of scyphomedusae, three species of hydromedusae, two genera of siphonophores, and two species of ctenophores were observed in the videos, at depths between 50 and 400 m. None of these species had been previously recorded in the waters around the island. Furthermore, except for the jellyfish Pelagia noctiluca and a siphonophore in the genus Praya, all are new records for Costa Rican waters. This study also includes the first record of the cnidarians Modeeria rotunda, Solmissus sp., Halitrephes maasi and Apolemia spp., and the ctenophore Thalassocalyce inconstans in the Eastern Tropical Pacific. We show that surveys in regions with little information about gelatinous zooplankton may broaden our knowledge of their natural history and may result in new records of gelatinous species.

Insight into the cryptic diversity and phylogeography of the peculiar fried egg jellyfish Phacellophora (Cnidaria, Scyphozoa, Ulmaridae)

“…Later, Phacellophora continued to be observed in great numbers in the chilly waters of the N Pacific and NW Atlantic ( e.g. , Brodeur et al, 2006 ; Zavolokin, Glebov & Kosenok, 2008 ; Il’inskii & Zavolokin, 2011 ), and much more sporadically in the SE, SW and E Pacific ( Fagetti, 1973 ; Larson, 1986 ; Corrales-Ugalde et al, 2017 ), W Africa ( Stiasny, 1934 , 1940 ; Kramp, 1955 , 1961 ; Hoving et al, 2018 ), Mediterranean ( Dragičević et al, 2019 ) and NE Atlantic ( e.g. , Stiasny, 1940 ; Moro et al, 2020 ; this study) ( Figs.…”

Editorial

“…The beauty and complexity of gelatinous zooplankton is highlighted on our front cover and in their paper Corrales-Ugalde et al . (2018) expand our knowledge of these delicate organisms through opportunistic sampling in an underwater tourism vehicle. Detailed work of Kornienko et al (2018) reveals the complete larval development of Leonardsaxius amurensis for the first time and Plotkin et al (2018) provide a systematic overview of the Polymastiidae of the Nordic and Siberian seas.…”