The scyphozoan Pelagia noctiluca (Forsskål, 1775) is the most common and widely distributed jellyfish in the Mediterranean Sea. Also, and because of its predatory effects on zooplankton community and its interactions with human activities, it is usually considered the most important jellyfish in Mediterranean waters. The ecology of adult medusae has been extensively studied. Contrariwise, due to the holoplanktonic life cycle (i.e. lack of benthonic stage) allowing its reproduction offshore, basic ecological knowledge about their larval stages (i.e. ephyrae) remains scarce. Therefore, insights about its ephyrae distribution and ecology would contribute to better understand the general ecology of the species. This work is focused on summer distribution (July-August 2016) of P. noctiluca ephyrae collected offshore at 75 stations within a large-scale sampling in the NW Mediterranean (CONECTA project). Regarding their horizontal distribution, the ephyrae were absent at the north of the study area, probably because of cold waters inflow from the Gulf of Lions by the Northern Current. At the south of the sampling area, the entering flow of the Atlantic Ocean waters would explain the higher abundances detected. Regarding vertical distribution, they are located between surface and 50 m, above the pycnocline, with similar abundances at 0-25 m and 25-50 m depth

6th International Jellyfish Blooms Symposium, 4-6 November 2019, Cape Town, South Africa