Eudendrium album Nutting 1898

Eudendrium album Nutting, 1898

Fig. 13 A–D

See Schuchert (2008b) for a complete synonymy.

Material examined. HCUS-S 0 15 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

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

Hydroid. Hydrorhiza as creeping, branching stolons; colonies stolonal or erect; hydrocauli monosiphonic, small and delicate, unbranched or little branched, perisarc smooth with some corrugated or annulated stretches at base of hydrocladia and hydranths; hydranths cup-shaped, somewhat tapering towards base, 1–20 hydranths per shoot (up to 50 possible); hypostome rounded, large; with around 17–22 tentacles. Gonophores as fixed sporosacs, females develop in one whorl of about six sporosacs on body of a normally developed hydranth, with unbranched spadix when mature; males 2–3 (mostly 2) chambered, arising as a single whorl from lower part of the hydranth body. Colours: perisarc of stem brown to yellowish, branches yellowish-brown fading to colourless; hydranths white to cream coloured.

Cnidome. Heterotrichous microbasic euryteles on tentacles, almond-shaped; larger macrobasic euryteles (27.5–29.0 x 10.0–11.0 Μm), shaft in intact capsule in 4–5 coils that are oblique in relation long axis of capsule, confined to upper 2/3 of capsule.

Habitat type. Occurs from the intertidal to about 1000 m depth on various substrates (Schuchert, 2012).

Substrate. Stones, algae, bryozoans and other hydroids.

Seasonality. In the Ligurian Sea (Boero & Fresi 1986) from September to May, in Salento waters in August (De Vito 2006; this study).

Reproductive period. In the Ligurian Sea, reproductive colonies occur from October to March (Boero & Fresi 1986).

Distribution. Mediterranean to North Atlantic (Marinopoulos 1992; Marques et al. 2000a; Bouillon et al. 2004; Gravili et al. 2008a; Schuchert 2008b).

Records in Salento. Rare, at: Torre dell’Inserraglio, S.ta Caterina, La Strea, La Rotonda, Ponte del Ciolo (Presicce 1991); Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; this study).

Remarks. Shallow-water colonies small, sometimes stolonal, cold-water colonies larger (see Schuchert 2008b). Watson (1985) and Marques et al. (2000a) redefined this species by asserting that its identification depends on the presence of macrobasic euryteles.

References. Motz-Kossowska (1905), Stechow (1923), Boero & Fresi (1986), Marinopoulos (1992), Marques et al. (2000a), Bouillon et al. (2004), De Vito (2006), Gravili (2006), Gravili et al. (2008a), Morri et al. (2009), Puce et al. (2009) all as E. fragile; Schuchert (2008b, 2012).