Antennella secundaria (Gmelin, 1791)

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 : 98-99

Antennella secundaria (Gmelin, 1791)

Fig. 69 A, B

See Calder (1997) for a complete synonymy.

Material examined. HCUS-S 0 76 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Schuchert 1997):

Hydroid. Hydrorhiza as ramified, tubular stolons; colonies erect; hydrocladia usually unbranched, up to about 25 mm, basal part of the axis divided into several internodes by transverse nodes, with a variable number of nematothecae, rest of the stem heteromerously segmented, hydrothecate segments with one hydrotheca surrounded by 4 nematothecae, one median inferior inmovable, one pair of laterals, and one axillar, non-hydrothecate internode with 2 median nematothecae; hydrothecae cup-shaped, walls parallel to slightly divergent, 1/3 to 1/2 adnate, rim even, aperture at 45º–55º from the main axis; nematothecae all two-chambered and with a very wide embayment, median inferior inmovable, not reaching the level of the hydrotheca, median nematotheca on the internodes similar, axillar nematotheca similar but much shorter than the first, lateral nematothecae movable, borne on well developed pedicels, basal chamber elongated, distal chamber widening distally. Gonothecae of both sexes often on the same stem, borne below hydrothecae, on pedicels of 2 segments, female ones elongated, cylindrical, narrowed basally, with a circular lid and 2 opposite basal nematothecae, male ones shorter, curved, also provided with 2 basal lateral nematothecae. Colour: coenosarc reddish.

Cnidome. Microbasic mastigophores.

Habitat type. Eurybathic zone from almost the tidal level to 550 m depth ( Broch 1933; García Carrascosa 1981; Boero & Fresi 1986; Ramil & Vervoort 1992).

Substrate. Algae, Posidonia , hydroids, polychaete tubes, coral fragment, sponges, bryozoans.

Seasonality. Present all year ( Boero & Fresi 1986; De Vito 2006; this study) in the Mediterranean Sea.

Reproductive period. From March to November ( Boero & Fresi 1986) in the Ligurian Sea; April, October, November (De Vito 2006; this study) in Salento waters.

Distribution. Cosmopolitan species with a preference for warmer waters (Ramil & Vervoort 1992; Medel & Vervoort 1995; Medel & López-González 1996; Peña Cantero & García Carrascosa 2002; Bouillon et al. 2004; Gravili et al. 2008).

Records in Salento. Common at the following localities: Torre dell'Inserraglio, Montagna Spaccata, Torre S. Emiliano, La Rotonda, Il Chiapparo, S.ta Caterina, Ponte del Ciolo, ( Presicce 1991); Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008a; this study); La Strea (Porto Cesareo) ( Ventura 2011);

Remarks. Intersegment length and hydrothecae size are quite variable, even among colonies from the same locality ( Broch 1933).

References. Carus (1884), Kirchenpauer (1876), Marktanner-Turneretscher (1890), Babic (1910), Broch (1912, 1933) all as Plumularia secundaria ; Neppi (1917), Stechow (1919, 1923), Leloup (1934), Picard (1958a), Riedl (1959), Schmidt (1973), Balduzzi et al. (1980), García Carrascosa (1981), Boero (1981a, b), Fresi et al. (1982), Boero (1985), Boero & Fresi (1986), Gili (1986), Roca (1986), García-Rubies (1987, 1992), Roca et al. (1991), Ramil & Vervoort (1992), Álvarez Claudio (1993), Medel & Vervoort (1995), Ramil et al. (1998), Morri & Bianchi (1999), Morri et al. (1999), 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), Puce et al. (2009), Bianchi et al. (2011), Ventura (2011).

Figures

FIGURE 69. Antennella secundaria: A, hydrocladium; B, part of axis with gonotheca (A, B same scale bar) (drawn by F. Boero). Scale bar: 250 µm.