Eugymnanthea inquilina Palombi, 1935

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 : 86-87

Eugymnanthea inquilina Palombi, 1935

Fig. 59 A, B

See Kramp (1961) for a complete synonymy.

Material examined. HCUS-S 0 66 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp stage.

Description (based on our own observations; Palombi 1935; Kramp 1959; Kubota 1979, 1983):

Hydroid. Epizootic on gills of bivalves, solitary or forming small colonies; hydranth tubular, without hydrothecae, with a conical hypostome; with a single whorl of 20–24 filiform tentacles; with an intertentacular membranous web, fixed to the host by a basal disc; often young hydranths budding from the middle part of the primary hydranth body; 1–2 medusa buds at the basal part of the hydranths. Colour: hydroid yellow-orange.

Habitat type and substrate. Hydroid living in bivalve Mollusca such as Ruditapes decussatus , Mytilus galloprovincialis and others ( Palombi 1935; Cerruti 1941 as Mytilhydra polimantii ; Morri 1981a, b; Gili, 1986; Brinckmann-Voss 1987; Piraino et al. 1994).

Seasonality. From April to November ( Palombi 1935; Piraino et al. 1994) in theTyrrhenian and Ionian Seas.

Reproductive period. April–November ( Palombi 1935; Piraino et al. 1994).

Medusa. Umbrella sphero-conical up to 0.55 mm high and wide, without manubrium and tentacles; 4 simple radial canals; 4 large, sac-like gonads on radial canals, not lobular, 8 adradial statocysts with 3 or 4 statoliths.

Cnidome. Basitrichous isorhizas.

Distribution. Endemic to Mediterranean Sea ( Medel & López-González 1996; Bouillon et al. 2004; Gravili et al. 2008a).

Records in Salento. Common in the Ionian Sea ( Piraino et al. 1994; Kubota 2000) and Adriatic Sea, Apulian coasts ( Kubota 2000).

Remarks. The whole life cycle was examined in the present study. For more details about the systematics and ecology of this species see Kubota (1983, 1989, 2000), Piraino et al. (1994), Govindarajan et al. (2005).

References. Kramp (1961), Kubota (1979, 1983, 1985, 1987, 2000), Gili (1986), Gili et al. (1988), Piraino et al. (1994), Bouillon et al. (2004), Gravili et al. (2008a).

Figures

FIGURE 59. Eugymnanthea inquilina: A, hydranth with gonophore; B, eumedusoid (A and B same scale) (redrawn and modified after Morri 1981 by A. Gennari). Scale bar: A, B, 0.5 mm.