Eudendrium glomeratum Picard, 1951

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 : 28-29

Eudendrium glomeratum Picard, 1951

Fig. 17 A–F

See Schuchert (2008b) for a complete synonymy.

Material examined. HCUS-S 0 20 and HCUS-S 0 21 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Marinopoulos 1992; Marques et al. 2000a, b; Schuchert 2008b, 2012):

Hydroid. Hydrorhiza rhizocaulomic; colonies erect, up to 30 cm high; hydrocauli polysiphonic, branched, with thick perisarc in older parts, becoming thin in younger regions; hydranths urn-shaped, with a ring composed of several nematocyst buttons (4–10) that sometimes coalesce into an irregular band, some buttons also scattered on hydranth body; hypostome flared; 15–28 filiform tentacles in one whorl. Gonophores as fixed sporosacs; females developed on reduced hydranth (4–6 gonophores per blastostyle) with unbranched spadix; males provided with 1–2 chambers; mature blastostyle with either a normal number of tentacles or a reduced number partly atrophied tentacles, with or without terminal buttons. Colours: perisarc brown in older parts, becoming yellowish to transparent in younger regions; hydranths red.

Cnidome. Holotrichous macrobasic euryteles (24x10 to 28 x11 µm), butt long (4 times length of capsule) and spirally coiled around the big axis of the cnidocyst; these cnidocysts are concentrated in several groups characteristically conspicuous at the basal half of the polyp; also heterotrichous microbasic euryteles (6x 2.5 to 9x 4 mm) on tentacles and ectoderm.

Habitat type and substrate. It occurs on various solid substrata (rocky walls, caves, hard substrates, detritus, biogenic banks, Posidonia ); depth range 0–200 m ( Peña Cantero & García Carrascosa 2002), more commonly in depths of 10–40 m ( Picard 1951a; Rossi 1961; Boero 1981a, 1983; Bavestrello 1985; Boero & Fresi 1986; Arillo et al. 1989; Roca et al. 1991; Bavestrello & Arillo 1992; Bavestrello & Cerrano 1992; Bavestrello et al. 1996; Morri & Bianchi, 1999; Piraino et al. 1999; Marques et al. 2000a; Faucci & Boero 2000; Peña Cantero & García Carrascosa, 2002; Morri et al. 2009; Puce et al. 2009).

Seasonality. In the Ligurian Sea ( Boero & Fresi 1986) from October to April ( Boero & Fresi 1986; Boero et al. 1986), and January–May, July–December (Puce et al. 2009); all year in Salento waters (De Vito 2006; this study).

Reproductive period. In the Mediterranean, fertile colonies can be found all year round ( Peña Cantero & García Carrascosa 2002; Schuchert 2008b), but the peak of reproduction seems to be during autumn and winter ( Boero 1984; Boero et al. 1986; De Vito 2006; Puce et al. 2009; this study).

Distribution. Rather common and widespread in the western and eastern Mediterranean, including the African and Israeli coasts ( Schuchert 2008b); Northeastern Atlantic, Indo-Pacific (distribution probably wider; it resembles the species E. ramosum , and many records under this name could possibly belong to E. glomeratum ).

Records in Salento. Common at Porto Cesareo ( Faucci & Boero 2000), and Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; this study).

References. Motz-Kossovoska (1905) as E. ramosum, Picard (1958a) , Rossi (1971), Boero & Fresi (1986), Roca (1986), Boero & Cornelius (1987), Bavestrello & Cerrano (1992), Marinopoulos (1992), Altuna (1994), Medel & López-González (1996), Marques et al. (2000a, b), Peña Cantero & García Carrascosa (2002), Bouillon et al. (2004), Puce et al. (2005a, 2009), De Vito (2006), Gravili (2006), Gravili et al. (2008a), Schuchert (2008b, 2012), Morri et al. (2009), Bianchi et al. (2011).

Figures

FIGURE 17. Eudendrium glomeratum: A, typical colony; B, hydranth with characteristic nematocyst buttons; C, male blastostyle; D, female blastostyle; E, particular of a female gonophore (C, D, E same scale bar); F, nematocysts: intact macrobasic euryteles (drawn by C. G. Di Camillo). Scale bars: A, 2.0 cm; B, 0.5 mm; C, D, E, 0.2 mm; F, 10 µm.