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A rapid temperature increase in the 1980-90s has been accompanied by dramatic and unprecedented changes in the biota and communities of the Ligurian Sea. This review uses existing historical series (a few of which have been purposely updated) to assess extent and consequences of such changes. A number of warm-water species, previously absent or occasional in the comparatively cold Ligurian Sea, has recently established thanks to warmer winters. Occurrence among them of invasive alien species is causing concern because of their capacity of outcompeting autochthonous species. Summer heatwaves, on the other hand, caused mass mortalities in marine organisms, some of which found refuge at depth. New marine diseases appeared, as well as other dysfunctions such as the formation of mucilage aggregates that suffocated and entangled benthic organisms. Human pressures have combined with climate change to cause phase shifts (i.e., abrupt variations in species composition and community structure) in different habitats, such as the pelagic environment, seagrass meadows, rocky reefs, and marine caves. These phase shifts implied biotic homogenization, reduction of diversity, and dominance by invasive aliens, and may be detrimental to the resilience of Ligurian Sea ecosystems. Another phase of rapid warming has possibly started in the 2010s and there are clues pointing to a further series of biological changes, but data are too scarce to date for proper assessment. Only well addressed long-term studies will help understanding the future dynamics of Ligurian Sea ecosystems and their possibilities of recovery. [ABSTRACT FROM AUTHOR]

One hundred and six specimens of the Por's goatfish, Upeneus pori Ben-Tuvia & Golani (1989), a Lessepsian species native to the Western Indian Ocean, were collected from bottom trawlers' catches from 2012 to 2016 on the deep shelf off the southern coast of Lampedusa Island (Strait of Sicily, Central Mediterranean Sea). Since it first appeared in Iskenderun Bay (Turkey) in 1950, the Por's goatfish has quickly spread in Levantine Sea waters to become a commercial species used by local fisheries, while continuing its range expansion along the south-eastern coasts of the Mediterranean. Because the Strait of Sicily currently represents the westernmost sector of this species distribution area, it might serve as a stepping-stone for this species' expansion in the western basin of the Mediterranean. Supporting this hypothesis was our finding of specimens with post-spawning gonads. The pattern of westward expansion by the Por's goatfish in the Mediterranean Sea and its settlement in the Strait of Sicily are discussed in relation to the warming trend over the last 30 years. [ABSTRACT FROM AUTHOR]

The reproductive state of the commercial sea urchin Paracentrotus lividus was investigated during one year along a sector of the Ionian Sea of the Apulia region (Southern Italy). Gonadosomatic index, Repletion index and histological methods, categorized by four stages for females and two for male specimens were utilized to assess the reproductive cycle throughout an entire year with monthly sampling in four sites situated to north and south of Torre Suda (Gallipoli Municipality, Province of Lecce). The four populations exhibited similar reproductive pattern, having mature gonads and gonadal reconstitution during almost all months. The population from south of Torre Suda in August and March had the highest Gonadosomatic index values, the highest Gonadosomatic index values for the population north of Torre Suda was observed in February, March and April. Events of spawning were observed in spring, summer and autumn south of Torre Suda and in winter north of Torre Suda. In particular, spawning events were observed in medium-sized sea urchin (diameter 36–50 mm) with a high Repletion index value. [ABSTRACT FROM AUTHOR]