Halecium tenellum Hincks 1861

• Main Authors: Gravili, Cinzia, Vito, Doris De, Camillo, Cristina Gioia Di, Martell, Luis, Piraino, Stefano, Boero, Ferdinando
• Format: Other/Unknown Material
• Language: unknown
• Published: 2015
• Subjects: Biodiversity; Taxonomy; Animalia; Cnidaria; Hydrozoa; Leptothecata; Haleciidae; Halecium; Halecium tenellum; Arctic; Antarctic; Pacific; Vito; Antarc*; Pacific Arctic
• Online Access: https://zenodo.org/record/6107099; https://doi.org/10.5281/zenodo.6107099

Halecium tenellum Hincks, 1861 Fig. 67 A–C See Peña Cantero & García Carrascosa (2002) for a complete synonymy. Material examined. HCUS-S 0 74 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula). Description (based on our own observations; Peña Cantero & García Carrascosa 2002): Hydroid. Hydrorhiza stolonal, colonies erect; hydrocauli very thin and delicate, monosiphonic, up to 20 mm high, irregularly branched, internodes long, in a zigzag arrangement, separated by transverse nodes; hydrocladia may originate from hydrothecal base; hydrothecae shallow, walls widening from base to top giving a wide aperture, rim everted and curved outwards, borne laterally at upper part of internodes, alternate and provided with a well developed hydrophore, secondary hydrothecae provided with hydrophore, may arise from primary hydrothecae. Gonothecae: male gonothecae ovate and flattened, female similar but slightly larger and broader. Cnidome. Microbasic euryteles and mastigophores. Habitat type. Eurybathic species that has been found from 0.5 to 200 m depth (Marinopoulos 1979; Boero & Fresi 1986). Substrate. Algae, hydroids, concretions, Posidonia, bryozoans, polychaete tubes, anthozoans, sponge. Seasonality. April (Picard 1955; Gili 1986), May (Medel et al. 1998), and October–March, July (Boero & Fresi 1986) in the western Mediterranean; June, July (De Vito 2006; this study) in Salento waters. Reproductive period. April (Picard 1955; Gili 1986) and May (Medel et al. 1998) in the western Mediterranean. Distribution. Cosmopolitan species present in the eastern and western Atlantic, Mediterranean, Indo-Pacific, Arctic, Antarctic (Broch 1918 in part as Halecium textum; Stepan’yants 1979; Ramil & Vervoort 1992; Medel & López-González 1996; Medel et al. 1998; Peña Cantero & García Carrascosa 2002; Bouillon et al. 2004; Gravili et al. 2008 a; Soto Ãngel & Peña Cantero 2013). Records in Salento. Rare at Otranto (De Vito 2006; Gravili 2006; Gravili et al. 2008 a; this study). ...