Aglaophenia kirchenpaueri (Heller, 1868)

Fig. 52 A–D

See Svoboda & Cornelius (1991) for a complete synonymy.

Material examined. HCUS-S 0 58 and HCUS-S 0 59 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Svoboda 1979; Svoboda & Cornelius 1991):

Hydroid. Hydrorhiza as much branched stolons; colonies erect, pinnate; hydrocauli, monosiphonic, up to 200 mm, high basal part of the axis without thecae, followed by up to 3 prosegments each with a frontal nematotheca, remaining internodes with 3 nematothecae and a pseudonematotheca, nodes oblique; hydrocladia alternate, closely set, each cormidium with one hydrotheca and 3 nematothecae (one median inferior and 2 lateral ones), nodes transverse; hydrotheca not deep (length/breadth at rim: 1–1.3), with a greatly developed transverse abcauline septum recurved at the tip, rim with 9 marginal cusps, first pair on both sides longest, remaining marginal cusps grading towards axis of cormidium; median nematotheca not surpassing hydrothecal rim, 2/3 adnate, lateral nematothecae projecting slightly above hydrothecal rim, distal portion curved outwards, aperture of median and lateral nematothecae gutter-shaped; male corbulae partially open, usually without free costae, female ones usually closed and with free costa, colonies dioecious. Colours: hydrocauli yellowish to brown, hydrocladia and corbulae yellow or brown.

Cnidome. Microbasic mastigophores.

Habitat type. A. kirchenpaueri is a shelf and littoral species, found from almost the tidal level to 120 m depth in the Mediterranean Sea (Boero & Fresi 1986; Gili 1986; Templado et al. 1986; Svoboda & Cornelius 1991; Peña Cantero & García Carrascosa 2002), with a maximum depth at 373 m reported by Ramil and Vervoort (1992) around the Strait of Gibraltar.

Substrate. Hard substrates such as rock, coralline algae, gorgonians and barnacles but recorded seldom also on Cystoseira .

Seasonality. Reported, in the Mediterranean Sea, from January to December (Bouillon et al. 2004); from May to August, October and November in Salento waters (De Vito 2006; Piraino et al. 2013; this study).

Reproductive period. In the Mediterranean Sea, February (Picard 1955; Boero & Fresi 1986); April (Picard 1955; Gili 1986); May (Rossi 1961; Gili 1986); May–June, October (De Vito 2006; this study); August (Picard 1951b; Roca 1986); September (Picard 1951b; Boero & Fresi 1986), and November (Rossi 1971; Boero & Fresi 1986).

Distribution. Northeastern Atlantic from British coasts to Cape Verde Islands, Mediterranean (Svoboda 1979; Svoboda & Cornelius 1991; Ramil & Vervoort 1992; Medel & Vervoort 1995; Medel & López-González 1996; Ansín Agís et al. 2001; Peña Cantero & García Carrascosa 2002; Bouillon et al. 2004; Galea 2007; Gravili et al. 2008a; Puce et al. 2009; Soto Ãngel & Peña Cantero 2013).

Records in Salento. Moderately frequent at Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; Stabili et al. 2008; Ventura 2011; Piraino et al. 2013; this study).

Remarks. Colonies exposed to low current velocities may attain heights of up to 200 mm, conversely colonies growing in rapid currents remain short (Svoboda & Cornelius 1991).

References. Heller (1868) as Plumularia kirchenpaueri; Stechow (1919, 1923) as A. septifera; Leloup (1934), Riedl (1959, 1966, 1970, 1991) as A. septifera; Picard (1958a), Rossi (1961, 1971), Svoboda (1979), Boero & Fresi (1986), Svoboda & Cornelius (1991), Ramil & Vervoort (1992), Cornelius (1995), Medel & Vervoort (1995), Medel & López-González (1996), Piraino et al. (1999), Ansín Agís et al. (2001), Peña Cantero & García Carrascosa (2002), Bouillon et al. (2004), De Vito (2006), Gravili (2006), Galea (2007), Gravili et al. (2008a), Stabili et al. (2008), Puce et al. (2009), Piraino et al. (2013).