The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide Author Gravili, Cinzia Author Vito, Doris De Author Camillo, Cristina Gioia Di Author Martell, Luis Author Piraino, Stefano Author Boero, Ferdinando text Zootaxa 2015 3908 1 1 187 journal article 42365 10.11646/zootaxa.3908.1.1 6f1d1977-6b97-4789-828c-76ed250cf1ae 1175-5326 242729 D6AD2B49-170B-4D9C-84AA-DBE0FEEAD8BE Stylactaria inermis ( Allman, 1872 ) Fig. 11 A–C See Schuchert (2008a , 2013 ) for a complete synonymy. FIGURE 11. Stylactaria inermis : A , gastrozooid; B , dactylozooid (A, B same scale bar); C , nematocysts (drawn by C.G. Di Camillo). Scale bars: A, B, 0.5 mm; C, 10 µm. Material examined. HCUS-S 0 13 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula). Description (based on our own observations; Stechow 1919 , Boero 1981a both as Stylactis inermis ; Schuchert 2008a as Hydractinia inermis ): Hydroid. Hydrorhiza without spines, as a network of stolons, colonies stolonal, only slightly polymorphic as gastrozooids and gonozooids are rather similar and dactylozooids may be present or absent; gastrozooids up to 4.2 mm high, with a basal perisarc cup; hypostome conical; about 20 tentacles in two or several whorls; gonozooids up to 2 mm , with two whorls of about 6–16 tentacles; colonies unisexual. Gonophores fixed, or liberable eumedusoids. Colours: hydranths pale pink to brownish. Eumedusoid: radial canals and a narrow ring canal; no tentacle bulbs; no tentacle rudiments; no velum; females with 10– 20 eggs. Cnidome. Microbasic euryteles of two size classes, desmonemes; Boero (1981a) also found very small anisorhiza-type nematocysts. Habitat type . Posidonia , locally common on rocky coasts, occurs from a few meters to 40 m depth ( Boero & Fresi, 1986 ; Schuchert 2008a ). Substrate. Algae, Posidonia oceanica , sponges, hydroids, barnacles, polychaete tubes, and other fixed substrates. Seasonality. In the western Mediterranean Sea ( Stechow 1919 ; García-Rubies 1987 ; Schuchert 2008a ) in February, April–July; in the Ligurian Sea ( Boero & Fresi 1986 ) from October to May; in Salento waters from September to May (De Vito 2006; Schuchert 2008a ; this study). Reproductive period. In the western Mediterranean Sea, reproductive colonies occur in April ( Stechow 1919 ); April–May ( Boero & Fresi 1986 ); July ( García-Rubies 1987 ); February, April, May ( Schuchert 2008a ). Distribution. Endemic to the Mediterranean (see Bouillon et al. 2004; Gravili et al . 2008a ; Schuchert 2008a ). Records in Salento. Moderately frequent at: Torre dell’Inserraglio ( Presicce 1991 ); Otranto (De Vito 2006; Gravili 2006; Gravili et al . 2008a ; Ventura, 2011 ; this study). Remarks. Bouillon et al. (1997) characterized the gonophores as eumedusoids with 8 tentacular bulbs. Schuchert (2008a) described the gonophores as sporosacs. Onofri et al. (2010) recorded reverse development of liberated eumedusoids of S. inermis , with transformation into stolons and polyps as described in Turritopsis dohrnii (Bavestrello et al. 1992; Piraino et al. 1996), Laodicea undulata (De Vito et al. 2006) , and Perarella schneideri ( Piraino et al. 2004 ) . Miglietta & Cunningham (2012) referred this nominal species to Stylactaria . References. Stechow (1919 as Stylactis inermis , 1923 as Stylactella inermis ), Leloup (1934) as Podocoryna inermis , Riedl (1959 , 1966 ) as Stylactella inermis ; Boero (1981a , b ), Gili & Castelló (1985) , Boero & Fresi (1986) , Gili (1986), Roca et al. (1991) , Piraino et al. (1999) all as Stylactis ; Medel & López-González (1996) as Stylactaria ; Bouillon et al. (1997), Peña Cantero & García Carrascosa (2002) , Bouillon et al. (2004), De Vito (2006), Gravili (2006), Gravili et al . (2008a) , Schuchert (2008a) , Ventura (2011) all as Hydractinia inermis .