Garveia grisea ( Motz-Kossowska, 1905 )

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 : 13-14

Garveia grisea ( Motz-Kossowska, 1905)

Fig. 5 A–C

See Schuchert (2007) for a complete synonymy.

Material examined. HCUS-S 0 0 5 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Motz-Kossowska 1905; Stechow 1919; Schuchert 2007):

Hydroid. Hydrorhiza as creeping ramified stolons; colony erect and branched, up to 3 cm high; hydrocauli monosiphonic or basally polysiphonic, thick, without annulations; hydrocladia alternate, basally adnate to hydrocaulus, giving rise to secondary hydrocladia with the same arrangement; hydranths fusiform, borne on secondary branches, covered basally by a pseudohydrotheca; hypostome conical or dome-shaped, with one whorl of 7–10 filiform tentacles. Gonophores as ovoid fixed sporosacs, solitary or paired, borne on pedicels on hydrocladia, females with only one egg. Colours: perisarc grey, hydranth milky-white.

Cnidome. Microbasic euryteles and desmonemes abundant on tentacles; macrobasic heteronemes on hydranth body.

Habitat type. Rocky cliffs, sand and pebbles, hydroids (often on large Eudendrium colonies), and other living substrates (depth range: 0–80 m) ( Motz-Kossowska 1905; Boero & Fresi 1986; Morri et al. 1991; Puce et al. 2009).

Substrate. algae ( Cystoseira , Halimeda tuna , Peyssonnelia ), sponges, hydroids ( Eudendrium glomeratum , E. racemosum , E. ramosum , Dynamena disticha , Sertularella sp.), bryozoans, Ascidiacea.

Seasonality. From October to June in the Ligurian Sea ( Boero & Fresi 1986); at Otranto: from October to April (De Vito 2006; this study).

Reproductive period. From October to February ( Boero & Fresi 1986); at Otranto: February, from October to January (De Vito 2006; this study).

Distribution. Mediterranean (Bouillon et al. 2004; Gravili et al. 2008a; Morri et al. 2009; Puce et al. 2009), and West of Ireland (see Schuchert 2007).

Records in Salento. Common at Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; Piraino et al. 2013; this study).

Remarks. Garveia grisea is one of the few bougainvilliid hydroids that can be identified in the absence of gonophores (see Schuchert 2007). Some discrepancy exist about the arrangement of tentacles on G. g r i s ea hydranths, Schuchert (2007) describes this species with two whorls of oral tentacles instead of only one. References. Motz-Kossowska (1905), Stechow (1919), Picard (1958a), Rossi (1961, 1971), Boero & Fresi (1986), Morri et al. (1991), Bouillon et al. (2004), De Vito (2006), Gravili (2006), Schuchert (2007), Gravili et al. (2008a), Morri et al. (2009), Puce et al. (2009), Piraino et al. 2013.

Figures

FIGURE 5. Garveia grisea: A, fragment of a colony with gonophores; B, hydranth; C, nematocyst (A, redrawn and modified after Motz-Kossowska 1905 by C. G. Di Camillo; B, C drawn by C. G. Di Camillo). Scale bars: A, B, 0.1 mm; C, 10 µm.