A unified assessment of marine Mediterranean assemblages: a lesson from benthic hydroids

Abstract

Hydroids are important components of the communities of rocky bottom shallow coastal areas. The hydrozoan fauna of the Mediterranean Sea is probably one of most investigated in the world, with lots of faunistic and biogeographical studies. However, quantitative studies using the same sampling methodology and controlled sampling effort have been restricted to areas in the Western and Central Mediterranean. We compared hydroid assemblages in four areas of the Mediterranean Sea, from the Gulf of C adiz to the South Adriatic Sea, following the same sampling and quantification methodology. Our analysis showed the dominant Atlantic character of the assemblages of the Gulf of C adiz and the South Alboran Sea because of the influence of the inflowing Atlantic waters. Conversely, the hydroid assemblages of the North Alboran Sea were more similar to the assemblages in the Ligurian and in the South Adriatic, and with a number of species ranking between the observed in these two Mediterranean zones. Fourteen species were identified as making the most significant contributions to characterizing the Mediterranean hydroid species pool from a quantitative point of view. These taxa include species previously named as typical components of the Mediterranean hydroid fauna as well as those only recently recorded in the region (Eudendrium moulouyensis) and invaders such as Clytia hummelincki.

Biodiversity and biogeography of hydroids across marine ecoregions and provinces of southern South America and Antarctica

“…1, 7, 8; Tables S1-S3). A similar pattern was documented for Arctic hydrozoans (Ronowicz et al 2015), presumably related to high speciation (Mayr 1963) and low rates of higher taxa diversification along polar regions, also influenced by particular climatologic, geologic and oceanographic events (Gillespie and Roderick 2014).…”

“…Geographic records of hydroids are directly related to the wordwide distribution of hydrozoan taxonomists. The Mediterranean sea, for example, has a comparatively high richness of known hydrozoan species but also concentrates a large number of specialists in Hydrozoa and is one of the best studied areas of the world (Gravili et al 2013;González-Duarte et al 2015;Gravili 2016). In contrast, the deep-sea, polar regions, and vast areas of the South Atlantic and South Pacific have significant knowledge gaps (Henry et al 2008;Genzano et al 2009Genzano et al , 2017Peña Cantero 2014;Ronowicz et al 2015;Fernandez and Marques 2018).…”

Consequences of Stinging Plankton Blooms on Finfish Mariculture in the Mediterranean Sea

“…Obelia dichotoma is another common hydrozoan species in Mediterranean coastal areas (Bouillon et al, 2004;González-Duarte et al, 2016). This species was observed in the Almería and Málaga facilities throughout the year, both as hydroids and medusae forming part of biofouling and zooplankton communities.…”

Βenthic hydrozoan assemblages as potential indicators of environmental health in a Μediterranean Μarine protected area

“…Abundances were estimated by assigning an abundance value to each species following the methodology of Boero & Fresi (1986) also used in other studies focused in hydrozoan assemblages (e.g. Di González-Duarte et al, 2016). The abundance categories employed for each species in each sampling site were: 0 (absent), 1 (only one specimen present), 2 (scarce), 3 (common), 4 (abundant) or 5 (extremely abundant).…”