caa a22 4500 60552646X CHVBK 20210128100803.0 cr unu---uuuuu 210128e20150601xx s 000 0 eng 10.1007/s10531-015-0859-y doi (NATIONALLICENCE)springer-10.1007/s10531-015-0859-y Missing species among Mediterranean non-Siphonophoran Hydrozoa [Elektronische Daten] [Cinzia Gravili, Stanislao Bevilacqua, Antonio Terlizzi, Ferdinando Boero] Hydrozoa of the Mediterranean Sea are well known and a recent monograph covers 457 species. Mediterranean non-Siphonophoran Hydrozoa comprises 398 species, an increasing number due to continuous updates, representing about 10% of the 3,702 currently valid species reported in a recent world assessment of hydrozoan diversity. Many new records are non indigenous species, previously described species that occurred elsewhere and whose arrival was presumably caused by human activities. However, many species reported in the past are not recorded in recent times. Realistic assessments of species pools require addition of new species, but also subtraction of species not found since a certain period. With the confidence of extinction index, cases of putative extinction can be raised. Out of the 398 known species, only 162 (41%) have been reported in the last decade, while 53 (13%) are not recorded in the literature since at least 41years. According to the confidence of extinction index, 60% of the 53 missing species are extinct, and 11% are putatively extinct from the basin. From a biogeographical point of view, the missing species are: 34% endemic, 19% boreal, 15% Mediterranean-Atlantic, 11% Indo-Pacific, 11% circumtropical, 4% cosmopolitan, 2% tropical-Atlantic, 4% non-classifiable. Fluctuations in species composition into a certain area cause heavy variability in the expression of both structural and functional biodiversity. As consequence, the regional biodiversity should be analyzed through its temporal evolution, to detect changes and their possible causes. This approach has profound consequences on biodiversity assessments and also on the compilation of red lists. The Author(s), 2015 Biodiversity nationallicence Hydrozoa nationallicence Extinction nationallicence Confidence of extinction index nationallicence Gravili Cinzia Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut Bevilacqua Stanislao Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut Terlizzi Antonio Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut Boero Ferdinando Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut Biodiversity and Conservation Springer Netherlands 24/6(2015-06-01), 1329-1357 0960-3115 24:6<1329 2015 24 10531 https://doi.org/10.1007/s10531-015-0859-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10531-015-0859-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gravili Cinzia Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut NATIONALLICENCE 700 1- Bevilacqua Stanislao Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut NATIONALLICENCE 700 1- Terlizzi Antonio Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut NATIONALLICENCE 700 1- Boero Ferdinando Laboratory of Zoology and Marine Biology, Dipartimento di Scienze e Tecnologie Biologiche e Ambientali, Di.S.Te.B.A., Università del Salento, Via Prov.le Lecce-Monteroni, 73100, Lecce, Italy aut NATIONALLICENCE 773 0- Biodiversity and Conservation Springer Netherlands 24/6(2015-06-01), 1329-1357 0960-3115 24:6<1329 2015 24 10531