Hebella brochii (Hadzi, 1913)

Gravili, Cinzia, Vito, Doris De, Camillo, Cristina Gioia Di, Martell, Luis, Piraino, Stefano & Boero, Ferdinando, 2015, The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide, Zootaxa 3908 (1), pp. 1-187 : 105-106

Hebella brochii (Hadzi, 1913)

Fig. 74

See Boero et al. (1997a) for a complete synonymy.

Material examined. HCUS-S 0 81 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Boero et al. 1997a; De Vito, 2006):

Hydroid. Hydrorhiza reptant; colonies stolonal; hydrothecae with base wider or as wide as opening, flared margin, with perisarcal diaphragm, perisarcal thickenings and corrugated hydrothecal walls, pedicel short but distinct. Gonothecae cylindrical, with a smooth or slightly crenate wall, substantially larger than the hydroteca; provided with a 4-valved operculum; containing only one medusoide per gonotheca; born on the hydrorhiza, on a short stalk.

Eumedusoid: ovoid, with abundant exumbrellar nematocysts close to the umbrella margin; without manubrium, mouth and gastric cavity; with 4 radial canals and a circular canal; gonads already present when the medusoid is released, located centrally on each radial canal and are most developed in the distal portion; velum conspicuous; 4 primary perradial marginal bulbs devoid of tentacles, and 4 secondary marginal interradial bulbs smaller than the primary ones.

Cnidome. Microbasic mastigophores.

Habitat type and substrate. Epizoic on hydroid Synthecium evansi (depth range: 3–125 m) ( Stechow 1919, 1923; Boero & Fresi 1986; De Vito 2006; this study).

Seasonality. November–March ( Boero & Fresi 1986; De Vito 2006; this study) in the Mediterranean Sea.

Reproductive period. November (De Vito 2006) in Salento waters.

Distribution. Endemic to the Mediterranean ( Marinopoulos 1981; Boero et al. 1997a; Bouillon et al. 2004; Gravili et al. 2008a).

Records in Salento. Rare at Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; this study).

Remarks. Gonotheca and released eumedusoid of this species have been described by De Vito (2006).

References. Stechow (1919, 1923), Leloup (1934), Picard (1951a, 1958a), Riedl (1959), Marinopoulos (1981), Boero & Fresi (1986), Boero et al. (1997a), Bouillon et al. (2004), De Vito (2006), Gravili (2006), Gravili et al. (2008a).

Figures

FIGURE 74. Hebella brochii: two hydrothecae (modified after Boero et al. 1997 a). Scale bar: 250 µm.