Halecium lankesterii ( Bourne, 1890 )

Gil, Marta & Ramil, Fran, 2025, Hydroids (Cnidaria, Hydrozoa) from Guinea Bissau, Zootaxa 5577 (1), pp. 1-89 : 41

Halecium lankesterii ( Bourne, 1890)

( Fig. 7B )

Haloikema lankesterii Bourne, 1890: 395–396 , pl. 26 figs. 1–2. Halecium lankesterii : Vervoort, 1959: 221–224, figs 3–5.—Millard, 1975:153, fig. 50B–E.— Gili et al., 1989: 80, fig. 9.—

Cornelius, 1995a: 285–287, fig. 65.—eña Cantero & García Carrascosa, 2002: 66–69, fig. 13A–C.— Schuchert, 2005:

618–620, fig. 7. Halecium nanum : Medel & Vervoort, 2000: 18–21, fig. 4.

Material examined. BISSAU-0810, stn BS191, 10º18'25"– 10º19'20"N, 16º08'47"– 16º08'47"W, 24–25 m, 3-XI-2008: 12 colonies without gonothecae, up to 43 mm high, of which three growing on Diphasia digitalis , one on Eudendrium capillare , one on Idiellana pristis and one on a worm tube.

BISSAU-0810, stn BS193, 10º21'13"– 10º21'51"N, 16º10'17"– 16º10'56"W, 20–21 m, 3-XI-2008: six colonies (five with female gonothecae), up to 8 mm high, all growing on bryozoans.

BISSAU-0810, stn BS194, 10º21'59"– 10º22'36"N, 16º13'23"– 16º14'03"W, 21–24 m, 3-XI-2008: five colonies (two with female gonothecae and one with male gonothecae), up to 5 mm high, of which four growing on bryozoans and one on Idiellana pristis .

BISSAU-0810, stn BS195, 10º22'44"– 10º23'22"N, 16º15'37"– 16º16'18"W, 29 m, 3-XI-2008: four colonies with male gonothecae; all growing on bryozoans.

Remarks. As described by Vervoort (1959), our colonies have geniculate stems and, hydrocladia arising in a single plane.

Biology. Halecium lankesterii has been found growing on stones, algae, sponges, other hydroids species, anthozoans, bryozoans, worm tubes, bivalves and crustaceans ( Vervoort 1959; Cornelius 1995a; Peña Cantero & García Carrascosa 2002). In the northern hemisphere, fertile material has been found in April and between June and November ( Peña Cantero & García Carrascosa 2002; Schuchert 2005).

In our material, the colonies were found growing mainly on bryozoans, but also on other hydroids and worm tubes. Both female and male gonothecae were found in November.

Distribution. This species has an East-Atlantic distribution, occurring from the English Channel and North Sea to South Africa ( Schuchert 2005), with a record from Mozambique (Millard 1975). In Northwest Africa, it has been recorded from Guinea-Bissau and the Republic of Guinea ( Vervoort 1959; Gili et al. 1989). Its bathymetric distribution extends from 0 to 167 m (Millard 1975; Gili et al. 1989).

Our material was collected at depths between 20–29 m.

Figures

FIGURE 7. A. Halecium halecinum (Linnaeus, 1758) (stn BS147), portion of colony with male gonotheca. B. Halecium lankesteri (Bourne, 1890) (stn BS193), portion of colony. C–D. Halecium liouvillei Billard, 1934 (stn BS192); portion of colony (C); female gonotheca (D). E–F. Halecium marocanum Billard, 1934 (stn BS191); portion of colony (E); gonotheca (F). Scales: a–f, 0.5 mm.