On the taxonomic status of Holothuria (Holothuria) tubulosa (s. s.) from the Algerian coast with the description of a new Mediterranean species, Holothuria (Holothuria) algeriensis n. sp. (Echinodermata: Holothuroidea: Holothuriidae) Author Mezali, Karim Protection, Valorization of Coastal Marine Resources and Molecular Systematics Laboratory. Department of Marine Science and Aquaculture. Faculty of Natural Sciences and Life. Abdelhamid Ibn Badis University-Mostaganem, PO Box 227, Route nationale N ° 11, Kharrouba, 27000, Mostaganem, Algeria. Author Thandar, Ahmed S. School of Life Sciences, University of KwaZulu-Natal, P / Bag X 54001, Durban 4000, South Africa. Author Khodja, Ihcene text Zootaxa 2021 2021-06-03 4981 1 89 106 journal article 5927 10.11646/zootaxa.4981.1.4 fcb42055-1ae9-4705-b471-a6b9ab150e33 1175-5326 4897620 C86B7AAB-F7D3-4ED0-9C81-F141416F6118 Holothuria ( Holothuria ) stellati Delle Chiaje, 1824 Figure 4C , Table 4 Material examined. UF5468 , Sidi-Fredj , Algeria , 36°45.000’N , 2°50.000’E , 0.5–10 m , Summer 2006, 1 spec. UF5495 , Stidia , Algeria , 35°49.922’N , 0°1.174’O , 3 m , Summer 2006, 1 spec. LPVCMRMS2020.208, Ouillis , Algeria , 36°7.436’N , 0°15.219’E , 5 m , June 2020 , 1 spec. Description. Body dark brown dorsally ( Figure 4 Ca), light brown ventrally ( Figure 4 Cb); sometimes reaching a length of 30 cm and width of 5–6 cm . Dorsal surface arched, ventral surface flattened, the latter with fairly dense, scattered pedicels. Integument thick ( 0.70 µm ) and smooth. A row of 5–6 very large, straight pointed protuberances separated at equal intervals on both sides of body. Cuvierian tubules absent. Collar around mouth thick (about 3.50 mm ). Ossicles . Body wall tables with circular disc ( Figure 4 Cc) with wavy outline and 4 large central and 4 small peripheral perforations. Buttons ( Figure 4 Ce) of several types : (i) oval with irregular, rough, smooth and thick surfaces; (ii) larger ones slightly rectangular in shape, with smooth but sometimes with wavy outline; (iii) enlarged, rounded ones and (iv) those that are slightly warped in the middle. Perforated plates of the pedicels of two types : enlarged and elongated ( Figure 4 Cd). Tentacles with straight ( Figure 4 Cf) or slightly arched rods.