Halisarca dujardinii Johnston 1842

Halisarca dujardinii Johnston, 1842 (Figure 20) Halisarca dujardini Johnston, 1842: 192. Material examined: ESFM-POR / 2017-326, S17(b), 0–5 m, on Cladocora caespitosa, 3 specimens; ESFM-POR / 2017-43, S26, 0 –5 m, on Posidonia oceanica and Bryozoa sp, 3 specimens. Description: It is a thin-structured sponge (height 0.7–1.5 mm) in an encrusting form. Its color after fixation is light brown (Figure 20). It has a soft, gelatinous, and slightly elastic texture. The osculum distributed on the sponge’s surface is 0.2–0.4 mm in diameter. The collagen layer consists of collagen fibrils that are difficult to separate from each other and have a dense structure. Habitat and distribution: This species was frequently reported at depths of 0–50 m in association with stones, rocks shells and crabs (e.g. Inachus sp., Macropodia sp.) (De Voogd et al. 2024; Ackers et al. 1992). However, it was also reported from the deep sea (300 m) (Alander 1942). It is a species with a Mediterranean-Atlantic distribution (de Voogd et al. 2024). It was previously reported from the coast of Bermuda (Rützler 1986), the North Sea (Muller 2004), off the coast of Norway (Burton 1930), the Celtic Sea (Borojevic et al. 1968), the eastern Bering Sea (Fristedt 1887), the Azores (Cruz 2002), off the coast of Dakar (Lévi 1952), the Balearic (Bibiloni 1981; Bibiloni and Gili 1982), the Ligurian Sea (Sarà 1958, Boury-Esnault 1971), the Tyrrhenian Sea (Topsent 1925; Pulitzer-Finali & Pronzato 1976), the Adriatic Sea (Schulze 1877), the Aegean Sea (Voultsiadou-Koukoura & Koukouras 1993) and the Black Sea (Czerniavsky 1880). It is a new record for the fauna of the Turkish Seas.