Research Article Mediterranean Marine Science Indexed in WoS (Web of Science, ISI Thomson) and SCOPUS The journal is available on line at http://www.medit-mar-sc.net DOI: http://dx.doi.org/10.12681/mms.25837 New discoveries in Eastern Mediterranean mesophotic sponge grounds: updated checklist and description of three novel sponge species Tal IDAN1,2, Sigal SHEFER1,2, Tamar FELDSTEIN1,2 and Micha ILAN1 1 School of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 6997801, Israel 2 The Steinhardt Museum of Natural History, Israel National Center for Biodiversity Studies, Tel Aviv University, Ramat Aviv 6997801, Israel Corresponding author:
[email protected] Contributing Editor: Vasilis GEROVASILEIOU Received: 17 January 2021; Accepted: 24 March 2021; Published online: 8 April 2021 This article is registered in ZooBank under LSID urn: lsid:zoobank.org:author:BA9B3180-860F-48D6-8C5F-EAF8CCD8B130 Abstract Rich and diverse mesophotic sponge grounds were recently discovered along the easternmost part of the Mediterranean Sea (Israeli coast). Seven sites have been surveyed over the last decade (2009-2019) and the sponge specimens discovered and col- lected in these expeditions have increased the known sponge richness of the Israeli fauna by ~34%. Here we provide an updated checklist along with the distribution of the various species in seven mesophotic sponge grounds along the coast. Nine mesophotic species have been added, seven of which are new to the Israeli coast. Moreover, we describe three novel species: Hemiasterella verae sp. nov., Axinella venusta sp. nov., and Plakortis mesophotica sp. nov. H. verae sp.