Pachycordyle napolitana Weismann, 1883

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 : 14-15

Pachycordyle napolitana Weismann, 1883

Fig. 6 A–C

See Schuchert (2004) for a complete synonymy.

Material examined. HCUS-S 0 0 6 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula). Description (based on our own observations; Motz-Kossowska 1905 as Cordylophora annulata and Perigonimus neapolitanus ; Schuchert 2004):

Hydroid. Hydrorhiza reticular; colonies stolonal; hydrocaulus as pedicels usually less than 5 mm long, unbranched or rarely branched once, slender basally and widening distally; perisarc moderately thin, wrinkled throughout and terminating at base of hydranth; hydranths club-shaped; hypostome dome-shaped to fusiform; with 12–24 filiform tentacles in 3 or 4 close whorls, tentacles of one whorl alternating with those of adjacent whorls, proximal tentacles often smaller than distal ones. Colours: hydranth body orange or reddish, hypostome whitish.

Eumedusoid: 1–3 per hydranth pedicel, on short wrinkled stalk completely invested with detritus-covered perisarc, arising at some distance below hydranth; mature gonophore medusoid with a distinct subumbrella, short collar projecting into subumbrella; radial canal absent; circular canal presumably absent; vestigial manubrium simple and large; below manubrium a bubble-like gastrodermal chamber; gonads encircling manubrium in a thick layer. Females with 100– 150 eggs. Immature male gonophores resembling sporosacs; mature male sporosacs also medusoid and identical to female ones.

Cnidome. Desmonemes and microbasic euryteles.

Habitat type. Colonies usually grow on gastropod shells, mostly on muddy bottoms; known to occur in depths from a few meters to about 40 m ( Boero & Fresi 1986; Schuchert 2004).

Substrate. Mollusca ( Fusinus rostratus , Murex spp.) and other organisms, including sea grasses.

Seasonality. May, November–December in the Ligurian Sea ( Boero & Fresi 1986); May and June in Salento waters (De Vito 2006; this study).

Reproductive period. May in the Tyrrhenian Sea ( Stechow 1919); June in Salento waters (De Vito 2006; this study).

Distribution. Mediterranean (see Medel & López-González 1996; Bouillon et al. 2004; Schuchert 2004; Gravili et al. 2008a), Bermuda ( Calder 1988), Puerto Rico ( Wedler & Larson 1986 as Clavopsella annulata ).

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

Remarks. Pachycordyle navis , never recorded from the Mediterranean, is quite similar to the present species and occurs in brackish waters ( Schuchert 2004). The difference of biotopes (marine vs brackish) suggests that the two nominal species are distinct.

References. Hargitt (1904), Motz-Kossowska (1905), Lo Bianco (1909), Mayer (1910), Stechow (1912, 1919, 1923), Rodríguez-Rosillo (1914), Neppi (1921), Picard (1951a, 1958a), Riedl (1959), Kramp (1961), Chimenz Gusso & Taramelli Rivosecchi (1975), Marinopoulos (1979), Boero (1981a, b), Morri (1981a, b), Morri (1985), Piraino & Morri (1990), Piraino et al. (1999), Morri & Bianchi (1985), Boero & Fresi (1986), Piraino & Morri (1990), Medel & López-González (1996), Bouillon et al. (2004), Schuchert (2004), De Vito (2006), Gravili (2006), Gravili et al. (2008a).

Figures

FIGURE 6. Pachycordyle napolitana: A, hydranth; B, mature male medusoid; C, mature female medusoid (B, C same scale bar) (redrawn and modified after Schuchert 2004 by A. Gennari). Scale bars: A, 0.4 mm; B, C, 0.3 mm.