Aglaophenia picardi Svoboda, 1979

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 : 79-80

Aglaophenia picardi Svoboda, 1979

Fig. 54 A–D

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

Material examined. HCUS-S 0 61 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula). Description (based on our own observations; Svoboda 1979; Svoboda & Cornelius 1991):

Hydroid: Hydrorhiza as densely branched stolons; colonies erect; hydrocauli monosiphonic, up to 80 mm, without any basal prosegment but several transverse nodes may occur, remaining parts composed of thecate internodes bearing hydrocladia, each with 3 nematothecae and a pseudonematotheca nodes oblique; hydrocladia alternate, widely spaced, divided into cormidia by transverse nodes; hydrothecae deep (length/breadth at rim: 1.5), rim with 9 uniform cusps, adcauline septum in lower third of hydrotheca inconspicuous or absent; median nematothecae gutter shaped, almost complete adnate to the hydrothecae, this with almost a half of its length free, lateral nematothecae reaching hydrothecal rim; male corbulae with large openings between the pairs of opposite costae, female ones closed, with the proximal pairs of ribs almost free, colonies dioecious. Colours: axis brown, perisarc transparent, corbulae transparent to white.

Cnidome. Microbasic mastigophores.

Habitat type. A. picardi is most often found in shaded-dark locations subject to moderate-strong currents (common at 3–10 m depth, even up to 30 m with a maximum depth at 580 m) ( Boero & Fresi 1986; Svoboda & Cornelius 1991; Ramil & Vervoort 1992).

Substrate. It is commonly collected on a variety of substrates such as Posidonia , algae, sponges, barnacles, molluscs, bryozoans, and polychaete tubes.

Seasonality. In the Ligurian Sea, Aglaophenia picardi occurs from August to March ( Boero & Fresi 1986), January–March, June–August, November–December (Puce et al. 2009); in Salento waters, all year (De Vito 2006; this study).

Reproductive period. In the Mediterranean Sea, fertile colonies occur from September to March ( Boero & Fresi 1986); April–November ( Svoboda & Cornelius 1991); February (Puce et al. 2009).

Distribution. Northeastern Atlantic (N Spain, CapeVerde), Black Sea, Mediterranean ( Svoboda 1979; Isasi 1985; Svoboda & Cornelius 1991; Ramil & Vervoort 1992; Medel & Vervoort 1995; Medel & López-González 1996; Morri & Bianchi 1999; Morri et al. 1999; Ansín Agís et al. 2001; Peña Cantero & García Carrascosa 2002; Bouillon et al. 2004; Bianchi et al. 2011; Soto Ãngel & Peña Cantero 2013).

Records in Salento. Rare at Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; Ventura 2011; this study).

Remarks. A. picardi reabsorbs its fans in the form of stolons and cysts during the period of low plankton productivity and calm seas, regeneration usually starting with renewed wave action and food influx ( Svoboda 1976). It is the only species of the genus known to lack a prosegment (see Svoboda & Cornelius 1991 for details).

References. Svoboda (1976, 1979), Boero (1981a), Isasi (1985), Boero & Fresi (1986), Piraino & Morri (1990), Roca et al. (1991), Svoboda & Cornelius (1991), Ramil & Vervoort (1992), Vervoort (1993), Altuna (1994), Medel & Vervoort (1995), Medel & López-González (1996), Morri & Bianchi (1999), Morri et al. (1999, 2009), Piraino et al. (1999), Ansín Agís et al. (2001), Peña Cantero & García Carrascosa (2002), Bouillon et al. (2004), De Vito (2006), Gravili (2006), Gravili et al. (2008a), Puce et al. (2009), Ventura (2011).

Figures

FIGURE 54. Aglaophenia picardi: A, colony; B, basal part of caulus; C, fragment of hydrocladia showing hydrothecae and associated nematothecae (B, C same scale bar); D, corbula (drawn by C. G. Di Camillo). Scale bars: A, 10 mm; B, C, 0.5 mm; D, 1.0 mm.