Eudendrium carneum Clarke 1882

Eudendrium carneum Clarke, 1882

Fig. 16 A–F

See Schuchert (2008b) for a complete synonymy.

Material examined. HCUS-S 0 19 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula). Description (after Calder 1988; Bavestrello & Piraino 1991; Marques et al. 2000a, b; Schuchert 2008b):

Hydroid. Hydrorhiza as a creeping mass of stolons, rhizocaulomic; colonies erect, bushy, up to 105 mm high; hydrocauli polysiphonic, densely branched in a more or less alternating pattern, with thick perisarc, thinner towards distal end, annulated basally on hydrocladia and hydranth pedicels, also occasional annulations elsewhere; hydrocladia completely (major branches) or basally (secondary branches) polysiphonic; hydranths with shallow basal perisarc groove; hypostome large and flared; up to 32 filiform tentacles in one whorl. Gonophores as fixed sporosacs, born on hydranths; females (4–10) on reduced hydranths with partially atrophied tentacles, spadix bifid and acuminate, curving over egg, shed during development, embryos borne in perisarc-covered capsules arranged irregularly along annulated pedicel, terminal polyp eventually lost; males (> 10) in a tuft at end of pedicel, without vestiges of hydranth, each with up to 5 chambers, distal end of gonophore with scattered nematocysts. Colours: perisarc, brownish in older parts, paler towards distal end; hydranths red coloured, sporosacs red.

Cnidome. Heterotrichous anisorhizas (22.2–23.4x10.1–10.8 µm), on hydranth, hypostome and on the stem; shaft visible in undischarged cnidocysts; heterotrichous microbasic euryteles (9x 4 µm) on tentacles and ectoderm.

Habitat type. Intertidal to depths of about 20 m (Marques et al. 2000a), but it prefers shady environments (Bavestrello & Piraino 1991).

Substrate. Ship hulls, rocks.

Seasonality. In the western Mediterranean Sea in July (Gili 1986), October (Bavestrello & Piraino 1991), July–December (Marques et al. 2000a).

Reproductive period. In the western Mediterranean Sea, reproductive colonies occur in July (Gili 1986), and October (Bavestrello & Piraino 1991).

Distribution. Western and eastern Atlantic, Indian Ocean, Red Sea, western and central Pacific, Mediterranean (Fraser 1944; Vannucci 1954; Vervoort 1968; Watson 1985; Medel & López-González 1996; Marques et al. 2000a; Bouillon et al. 2004; Schuchert 2008b).

Records in Salento. Rare in Salento waters: Gulf of Taranto (S. Piraino, pers. observ.).

Remarks. This species often occurs on ship hulls and is thus potentially easily introduced to other regions (Millard 1975; Occhipinti-Ambrogi et al. 2011).

References. Vervoort (1968), Millard (1975), Gili (1986), Calder (1988), Bavestrello & Piraino (1991), Marinopoulos (1992), Marques et al. (2000a, b), Schuchert (2008), Morri et al. (2009).