Antennella secundaria ( Gmelin, 1791 )

Gil, Marta, Ramil, Fran & Agís, José Ansín, 2020, Hydroids (Cnidaria, Hydrozoa) from Mauritanian Coral Mounds, Zootaxa 4878 (3), pp. 412-466 : 433

Antennella secundaria ( Gmelin, 1791)

Antennella secundaria: Ramil & Vervoort, 1992: 143–145 , fig. 37a–d; Calder, 1997: 29–32, Fig. 7 ; Schuchert, 1997: 14–18, figs 3-4; Ansín Agís et al., 2001: 140–145, fig. 63; Peña Cantero & García Carrascosa, 2002: 100–102, fig. 18e–h.

Material examined. MAURIT-0911, stn MUDR01 , 16º08´24”N, 16º57´12”W, 488 m, 5-XII-2009: one colony, growing on Plumularia filicula , no gonothecae .

MAURIT-0911, stn MUDR02 , 16º08´50”N, 16º57´01”W, 462 m, 5-XII-2009: one colony on Lophelia pertusa , without gonothecae .

Biology. This species colonises a wide variety of substrates, such as algae, sponges, hydrozoans, anthozoans, bryozoans, polychaete tubes, barnacles and bio-concretions ( Peña Cantero & García Carrascosa 2002). Fertile material has been found throughout the year, except in January and December ( Ansín Agís et al. 2001).

In our material, one colony was growing on P. filicula and L. pertusa .

Distribution. The geographical distribution of A. secundaria was reviewed in detail by Ansín Agís et al. (2001). This species has a circumglobal distribution in temperate, subtropical and tropical waters, with a bathymetric range extending from the littoral zone to a depth of 2700 m ( Vervoort 2006). On the West African coast, it was specifically collected from Morocco ( Patriti 1970), West Sahara (Broch 1913), Canary Islands ( Ansín Agís et al. 2001), Mauritania ( Ansín Agís et al. 2001; Gil & Ramil 2017a), Cape Verde Islands ( Ansín Agís et al. 2001; Vervoort 2006), Guinea-Bissau ( Gili et al. 1989) and Ghana ( Buchanan 1957).

Our material was collected from depths of 462 to 488 m.

Remarks. The unbranched and heteronomous segmented axis and presence of four nematothecae in the hydrothecate internodes—one mesial inferior, two laterals and one reduced in the axil behind the free part of the adcauline hydrothecal wall—are the diagnostic features of this species.

Figures

FIGURE 7. A–E, Nemertesia freiwaldi n. sp., paratype (stn MUDR01): A, colony. B–D, detail of hydrocladia. E, detail of hydrocaulus with hydrocladia and male gonotheca. Scales: a, 2.5 cm; b–e, 0.3 mm.