Pachycordyle pusilla ( Motz-Kossowska, 1905 )

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 : 15-16

Pachycordyle pusilla ( Motz-Kossowska, 1905)

Fig. 7 A, B

See Schuchert (2004) for a complete synonymy.

Material examined. HCUS-S 0 0 7 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula).

Description (based on our own observations; Motz-Kossowska 1905; Schuchert 2004):

Hydroid. Hydrorhiza as creeping, smooth, mostly linear stolons; colonies mostly stolonal, up to 2 mm; hydrocaulus as hydranth pedicel, unbranched or rarely branched once, with thick, double-layered and basally annulated perisarc, widening distally into a shallow funnel; hydranth slightly club-shaped when fully relaxed, 0.7–1.2 mm long; hypostome high, dome-shaped; with 12–16 filiform tentacles scattered through distal half or in 3 whorls. Gonophores as fixed sporosacs, ovoid to elongated, covered by loose, thin periderm, fixed sporosacs, borne distally on hydranth pedicels, 1–4 per pedicel; without radial or circular canals; no velum; simple spadix present, proximal gastrodermal chamber large. Females with 4, occasionally 5, eggs in a single tier. Colours: eggs uncoloured, clear.

Cnidome. desmonemes and microbasic euryteles.

Habitat type. Phanerogames in sea water of normal salinity (depth range: 0–30 m) ( Boero & Fresi 1986; Schuchert 2004; Puce et al. 2009).

Substrate. Phanerogames ( Posidonia oceanica and Zostera leaves, Cymodocea nodosa ), algae, concretions.

Seasonality. March, April, August, October, December ( Boero & Fresi 1986); January (Puce et al. 2009) in the Ligurian Sea.

Reproductive period. Along the Mediterranean French coast ( Motz-Kossowska 1905) reproductive colonies occur in August and May ( Schuchert 2004), October in the Ligurian Sea ( Boero & Fresi 1986),

Distribution. Endemic to the Mediterranean ( Morri 1980a as C. pusilla ; Medel & López-González 1996; Bouillon et al. 2004; Schuchert 2004; Gravili et al. 2008a).

Records in Salento. Rare at Otranto (this study).

Remarks. Schuchert (2004) used the new combination Pachycordyle pusilla ( Motz-Kossowska, 1905) . Reproduction, in this species, leads to reduction of hydranths ( Leloup 1930).

References. Motz-Kossowska (1905) as Cordylophora pusilla ; Leloup (1930), Picard & Roch (1949) both as Tubiclava pusilla ; Picard (1958a), Boero (1981a), Medel & López-González (1996) all as Cordylophora pusilla ; Schuchert (2004) as Pachycordyle pusilla ( Motz-Kossowska, 1905) comb. nov.; Gravili (2006), Gravili et al. (2008a), Puce et al. (2009).

Figures

FIGURE 7. Pachycordyle pusilla: A, male hydranth with gonophores; B, nematocysts (1: microbasic eurytele; 2: desmoneme) (modified after Boero 1981 a). Scale bars: A, 0.5 mm; B, 10 µm.