We have compiled available records in the literature for medusozoan cnidarians and ctenophores of South America. New records of species are also included. Each entry (i.e., identified species or still as yet not determined species referred to as “sp.” in the literature) includes a synonymy list for South America, taxonomical remarks, notes on habit, and information on geographical occurrence. We have listed 800 unique determined species, in 958 morphotype entries: 5 cubozoans, 905 hydrozoans, 25 scyphozoans, 3 staurozoans, and 20 ctenophores. Concerning nomenclatural and taxonomical decisions, two authors of this census (Miranda, T.P. & Marques, A.C.) propose Podocoryna quitus as a nomen novum for the junior homonym Hydractinia reticulata (Fraser, 1938a); Euphysa monotentaculata Zamponi, 1983b as a new junior synonym of Euphysa aurata Forbes, 1848; and Plumularia spiralis Milstein, 1976 as a new junior synonym of Plumularia setacea (Linnaeus, 1758). Finally, we also reassign Plumularia oligopyxis Kirchenpauer, 1876 as Kirchenpaueria oligopyxis (Kirchenpauer, 1876) and Sertularella margaritacea Allman, 1885 as Symplectoscyphus margaritaceus (Allman, 1885).

First record of the genus Cladonema (medusae and polyps) in Colombia

El subfilo Medusozoa (clases Cubozoa, Hydrozoa y Scyphozoa) se caracteriza por un esquema corporal predominantemente medusoide. El subfilo agrupa organismos con características pelágicas, lo que en cierta medida ha dificultado su conocimiento y estudio. En el Caribe colombiano se han registrado 25 de las 130 especies presentes en el mar Caribe, pero se considera que aún debe ahondarse en el conocimiento en torno a su diversidad local y regional. En este trabajo se registró la composición de las especies de Medusozoa presentes en algunas localidades del departamento del Atlántico, con énfasis en el sector turístico de Puerto Velero. Los registros se obtuvieron entre agosto de 2016 y diciembre de 2017. Las muestras se recolectaron de diversas formas: manualmente, utilizando arrastres superficiales con una red rectangular (1 mm de apertura de malla), o durante actividades de pesca. Se observaron siete especies: una de Hydrozoa, una de Cubozoa y cinco de Scyphozoa. Aurelia aurita y Chrysaora sp. fueron las más frecuentes en el sector de Puerto Velero. Aunque la mayoría de las especies son de distribución amplia o cosmopolita y ocasionalmente llegan a las costas del Caribe colombiano, en el Atlántico solo se tenía registro de una de ellas, por lo que estas observaciones amplían la información sobre su diversidad y frecuencia de aparición en esta zona del país, lo cual es de importancia para gestión y conservación en los lugares que desarrollan actividades turísticas. © 2018. Acad. Colomb. Cienc. Ex. Fis. Nat.

Corales de Profundidad National Natural Park (CPNNP), at the central Colombian Caribbean margin, has an extension of 142.195 ha with depths ranging from 34 to 1,234 m. The CPNNP’s essential ecological value isMadracisspp. as potential structure-forming deep-water coral; this work represents the first footages of these unique habitats for the Colombian Caribbean. In 11 sectors, remote video surveys are conducted, based on a detailed digital elevation model. From these sectors, four cover mesophotic zones (46–169m depth), and seven cover aphotic zones (up to 354m depth). After still images’ description and interpretation, a guide was generated with nine types of macrohabitats surrounding the coral formations of the CPNNP: soft substrate (mud/sand), soft substrate/rubble/rock with solitary corals, coral and shell rubble, rock/ledges with attached fauna, rugged stones with attached fauna, hard substrate with attached fauna, sandstone with attached fauna, soft substrate with burrows, and pockmark with attached fauna. Video transect analysis confirms the occurrence ofMadracisspp., with coral patches as the main framework builder of the CPNNP. These patches comprise many clumped 50 to 80 cm high coral colonies that developed over slow slopes, with seafloor elevations between 107 and 233 m and textured soils of soft and not very compact ridges, associated with the macrohabitat sandstone with attached fauna. This information is being used for the management and monitoring of this unique protected area.

To map ecological units in mesophotic coral ecosystems on the western side of San Andrés Island (Colombia) considering biotic components and geomorphic zonation among 30–140 m deep, 27 video transects were done using an ROV. In total, 14 h of video were recorded and 5742 still images were extracted from them, from which 753 met quality criteria for bottom coverage and organisms’ abundance estimations. These estimates were calculated from images through the Planar-Point Intercept method (PPI) using a 1 m × 0.5 m quadrant gridded 0.1 m × 0.1 m. CLUSTER, SIMPROF, and SIMPER analysis of benthic composition considering depth ranges in the group’s formation were done. The clusters formed were simplified and generalized using a color matrix to support the mapping process. Two geomorphological units were found, the deep reef terrace (30–60 m) and the reef slope (60–357 m), overlapping with five ecological units spanning 268 ha. The units Bioturbed sediments–Calcareous algae, Octocorals–Mixed corals, and Octocorals–Sponges sited on the deep reef terrace have been previously described in the shallow waters of the island, and the units Octocorals–Sponges–Antipatharians and Encrusting Sponges sited on the reef slope are described as new here. These findings contribute to the knowledge of Caribbean mesophotic coral ecosystems and are useful to update the Colombian coral reef atlas.