Sponges from rhodolith beds surrounding Ustica Island marine protected area (southern Tyrrhenian Sea), with a comprehensive inventory of the island sponge fauna

Abstract

<jats:p>The sponge fauna colonizing rhodolith beds from Ustica Island marine protected area was studied. Moreover, an inventory of the sponge species present along the island’s coasts was carried out for the first time. Analysis of rhodoliths trapped in nets used by local fishermen at two sites and data obtained from underwater video images were used to identify 25 sponge taxa, 22 of them at species level. The classes Demospongiae and Homoscleromorpha were present with 24 and 1 species, respectively. Most of the specimens were small-sized and represented by thick crusts or short erect branches. Few specimens were insinuating or excavating. Furthermore, qualitative sampling was performed on Ustica’s coralligenous formations, photophilous hard substrates and in marine caves, and the results obtained were added to the literature data. The overall checklist of sponges from Ustica encompassed 97 taxa, 90 named at species level, subdivided into 6 taxa of Calcarea, 3 of Homoscleromorpha and 88 of Demospongiae. Eleven of the species were endemic to the Mediterranean Sea, mainly concentrated on rhodoliths and in marine caves. This research adds a fundamental element to the knowledge of invertebrates associated with rhodoliths, and updates the checklist of sponges colonizing Ustica’s waters, facilitating its future monitoring.</jats:p>

Levelling-up rhodolith-bed science to address global-scale conservation challenges

“…maiteae (Santos et al, 2016), and several endemic coral (Cavalcanti et al, 2013;Pereira-Filho et al, 2015Amado-Filho et al, 2016;Negrão et al, 2021) and fish species (Moura et al, 2021). In the Mediterranean, the endemic deep-water kelp Laminaria rodriguezii (Barbera et al, 2003) and several species of endemic sponges (Longo et al, 2020) can be found on rhodolith beds, while in the NE-Atlantic the rare kelp L. ochroleuca and several rare rhodolith-associated seaweeds have been recorded (Peña et al, 2014;Braga-Henriques et al, 2022;Helias and Burel, 2023). At Cocos Island, Costa Rica, a new and endemic octocoral species, Rhodolitica oculta, has been found in association with rhodoliths (Breedy et al, 2021).…”

A Review of Rhodolith/Maerl Beds of the Italian Seas

“…The branches morphotype is associated with L. corallioides, P. calcareum, L. minervae, L. stic-taeforme, and L. racemus. The most associated fauna of the Italian calcareous algae beds include sponges, bryozoans, hydrozoans, polichaetes, molluscs, amphipods, gastropods, and echinoderms [24,25,[28][29][30][31]35,36].…”

“…The analysis of all the reported sites (Table 1) has also permitted an assessment of the main anthropogenic impacts affecting the Italian sites hosting coralline algae beds [25,30,40,43,45]. These impacts are mainly represented by litter (plastic, grass, wood, and metal objects) and by evidence of fishing activities (trawl marks and ghost net, longlines, lines, ropes, other fishing-related debris).…”

“…As regards the anthropogenic impacts, trawl marks over the soft bottom hosting coralline algae beds were observed both on the side-scan sonar mosaic and on ROV videos, where local accumulations of coralline algae inside the marks were sometimes observed (Figure 4c,d). [24,25,[28][29][30][31]35,36].…”

Invertebrate diversity associated with a shallow rhodolith bed in the Mediterranean Sea (Mar Piccolo of Taranto, south‐east Italy)

“…shell fragments or rocks). They are distributed worldwide and can be found at tropical (Amado‐Filho et al, 2012; Costa et al, 2020; Moura et al, 2021), temperate (Foster et al, 1997; Steller et al, 2003; Hinojosa‐Arango & Riosmena‐Rodríguez, 2004; García et al, 2014; Bracchi et al, 2019; Bracchi et al, 2022; Chimienti et al, 2020; Longo et al, 2020; Rendina et al, 2020; Romagnoli et al, 2021), and polar (Konar, Riosmena‐Rodriguez & Iken, 2006; Teichert et al, 2014; Ward et al, 2021) latitudes.…”