Kirchenpaueria pinnata (Linnaeus, 1758)

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 : 108-110

Kirchenpaueria pinnata (Linnaeus, 1758)

Fig. 77 A–C

See Ansín Agís et al. (2001) for a complete synonymy.

Material examined. HCUS-S 0 84 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Cornelius 1995; Ansín Agís et al. 2001):

Hydroid. Hydrorhiza as a network of branching stolons; colonies erect, pinnate; hydrocauli monosiphonic, up to about 42 mm, occasionally branched, basal part of the axis with several internodes separated by transverse nodes, distal part of axis segmented on internodes bearing hydrocladia, these on lateral apophyses at the upper part of the segment, apophysis with a naked nematophore on the upper side, another one is disposed laterally on the axis, just above the apophysis; hydrocladia alternate, with a first shorter athecate internode, with transverse node basally and oblique one distally (occasionally several of these internodes may occur), remaining internodes thecate or in an irregular sequence of thecate and athecate internodes separated by transverse nodes, thecate internodes with one hydrotheca and 2 nematophores, one median inferior and another median superior; hydrotheca cupshaped, walls gradually diverging, adcauline wall almost entirely adnate; median inferior nematophore with a minute scale-like nematotheca, median superior nematophore behind hydrotheca without theca. Gonothecae on hydrorhiza or in a row on the axis, with short pedicels. Similar in both sexes, sac-shaped, hexagonal in cross section, with 6 longitudinal ridges bearing digitiform prolongations of varied length, absent in some gonothecae.

Cnidome. Atrichous haplonemes, microbasic mastigophores and pseudostenoteles.

Habitat type. Eurybathic species found from the tidal level to about 150 m depth (García Carrascosa 1981; Boero & Fresi 1986; Ramil & Vervoort 1992).

Substrate. Recorded on wide variety of substrata including algae, Posidonia , hydroids, barnacles, on worm tubes, shells, sponges, and bryozoans.

Seasonality. Present all year ( Boero & Fresi 1986; Llobet i Nidal 1987; Llobet et al. 1991; De Vito 2006; Puce et al. 2009; this study) in the western Mediterranean Sea and in Salento waters.

Reproductive period. January–December ( Peña Cantero & García Carrascosa 2002) in the western Mediterranean Sea; March, April, July (De Vito 2006; this study) in Salento waters.

Distribution. Eastern Atlantic, Indo-Pacific, Mediterranean ( Cornelius 1995; Medel & Vervoort 1995; Medel & López-González 1996; Ansín Agís et al. 2001; Bouillon et al. 2004; Gravili et al. 2008a; Soto Ãngel & Peña Cantero 2013).

Records in Salento. Common at: Costa Merlata ( Fraschetti et al. 2002); Otranto ( Fraschetti et al. 2002; De Vito 2006; Gravili 2006; Andreano 2007; Gravili et al. 2008a; Piraino et al. 2013; this study); Torre Lapillo, Porto Cesareo, S.ta Caterina, Costa Merlata ( Andreano 2007).

Remarks. The colonies of Kirchenpaueria pinnata are highly variable. Generally colonies subjected to considerable water movement, are small, have one apophysis per stem internode and have intermediate athecate internodes in the hydrocladia; on the contrary, colonies from deeper water are larger, have big stem internodes with several apophyses and have no athecate internodes in the hydrocladia (for more details see Ansín Agís et al. 2001). The very similar nominal species Kirchenpaueria echinulata was considered valid in the past based on very variable features such as the number of branches per cauline internode, but morphological evidence suggests it should be treated as a synonym of K. pinnata , this being also the opinion shared by recent authors (Ramil & Vervoort 1992; Cornelius 1995; Bouillon et al. 2004).

References. Carus (1884) as P. pinnata and echinulata and helleri ; Marktanner-Turneretscher (1890) as P. hians ; Broch (1912), Babic (1913b) as P. similis ; Stechow (1919) as P. pinnata ; Broch, (1933), Leloup (1934), Riedl (1959, 1970, 1991), Rossi (1961) as K. echinulata ; Picard (1952, 1958a), Rossi (1971), Schmidt (1973), Repetto et al. (1977), García-Corrales et al. (1978), Boero (1981a, b), Boero et al. (1985), Boero & Fresi (1986), Gili (1986), Llobet et al. (1986, 1991), Garcia Rubies (1987), Llobet i Nidal (1987), Piraino & Morri (1990), Ramil & Vervoort (1992), Medel & Vervoort (1995), Medel & López-González (1996), Morri & Bianchi (1999), Morri et al. (1999), Piraino et al. (1999), Ansín Agís et al. (2001), Fraschetti et al. (2002), Peña Cantero & García Carrascosa (2002), Bouillon et al. (1986, 2004), De Vito (2006), Gravili (2006), Gravili et al. (2008a), Puce et al. (2009), Bianchi et al. (2011), Piraino et al. (2013).

Figures

FIGURE 77. Kirchenpaueria pinnata: A, general view of colonies; B, part of stem with origin of hydrocladium; C, gonothecae (A drawn by L. Basso; B drawn by F. Boero; C redrawn and modified after Cornelius 1995 by C. G. Di Camillo). Scale bars: A, 2.0 mm; B, 0.1 mm; C, 0.5 mm.