Nemertesia ventriculiformis ( Marktanner-Turneretscher, 1890 )

Gil, Marta & Ramil, Fran, 2025, Hydroids (Cnidaria, Hydrozoa) from Guinea Bissau, Zootaxa 5577 (1), pp. 1-89 : 69

Nemertesia ventriculiformis ( Marktanner-Turneretscher, 1890)

( Fig. 11F )

Plumularia ventriculiformis Marktanner-Turneretscher, 1890: 256–257 , pl. 6 figs 5, 5a.

Nemertesia ventriculiformis : Castric-Fey, 1970: 12–18, figs 15–22.— Ramil & Vervoort, 1992a: 177–180, fig. 45A–H.— Ansín Agís et al., 2001: 222–226, fig. 85.

Material examined. BISSAU-0810, stn BS133, 11º29'17"– 11º28'26"N, 17º15'14"– 17º15'14"W, 733–737 m, 23-X-2008: seven colonies without gonothecae, 40–70 mm high, of which five growing on worm tubes.

BISSAU-0810, stn BS147, 11º08'35"– 11º08'27"N, 17º11'31"– 17º10'37"W, 186–306 m, 26-X-2008: nine colonies without gonothecae, 13–122 mm high, of which one growing on Halecium halecinum .

BISSAU-0810, stn BS149, 11º06'46"– 11º07'39"N, 17º06'23"– 17º06'40"W, 71 m, 26-X-2008: one colony without gonothecae, 138 mm high, substrate unknown.

BISSAU-0810, stn BS152, 10º31'12"– 10º30'19"N, 17º12'34"– 17º12'32"W, 300–305 m, 27-X-2008: 18 colonies without gonothecae, 30–175 mm high, of which one growing on Lytocarpia myriophyllum .

BISSAU-0810, stn BS157, 10º19'36"– 10º18'44"N, 17º10'29"– 17º10'12"W, 304–308 m, 28-X-2008: three colonies without gonothecae, 29–176 mm high, substrate unknown.

BISSAU-0810, stn BS173, 10º04'52"– 10º04'17"N, 16º34'12"– 16º33'30"W, 277–278 m, 31-X-2008: three colonies without gonothecae, 47–163 mm high, substrate unknown.

BISSAU-0810, stn BS191, 10º18'25"– 10º19'20"N, 16º08'47"– 16º08'47"W, 24–25 m, 3-XI-2008: two colonies without gonothecae, 79 mm high, of which one growing on Diphasia digitalis .

Remarks. Nemertesia ventriculiformis is similar to N. norvegica (G.O. Sars, 1874) and N. falcicula (Ramil & Vervoort, 1992) with respect to the trophosome. The differences between all three species have been highlighted by Ansín Agís et al. (2001), and are mainly based on gonothecal features, with also some trophosomal differences. The presence of two lateral nematothecae,the shape and size of the hydrothecae and the presence of numerous,characteristic perisarcal ridges in the hydrocladial internodes allowed us to identify our material as N. ventriculiformis .

Our material represents the first record of this species for Guinea-Bissau.

Biology. In the northern hemisphere, colonies with gonothecae have been found in June, July, September, November and December ( Ansín Agís et al. 2001; Gil & Ramil 2017a).

In our material, some colonies were found growing on worm tubes and other hydroids, such as H. halecinum , L. myriophyllum and D. digitalis .

Distribution. Nemertesia ventriculiformis is an East Atlantic-Mediterranean species known from the Glénan Archipelago ( France) to Senegal including the Mediterranean Sea, with a bathymetric range extending from 10 to 930 m ( Ansín Agís et al. 2001). In West Africa, it has been collected from Morocco ( Ramil & Vervoort 1992a), Mauritania ( Gil & Ramil 2017a) and the Cape Verde Archipelago ( Ansín Agís et al. 2001).

Our material was collected at depths between 24–737 m.

Genus Plumularia Lamarck, 1816

Figures

FIGURE 11.A. Polyplumaria flabellata G.O. Sars, 1874(stnBS133), portion of colony with a hydrocladium.B. Pseudoplumaria marocana (Billard, 1930) (stn BS143), portion of hydrocladium. C. Kirchenpaueria pinnata (Linnaeus, 1758) (stn BS147), portion of hydrocladium. D–E. Nemertesia irregularis (stn BS132); portion of hydrocladium (D); female gonotheca (E). F. Nemertesia ventriculiformis (Marktanner-Turneretscher, 1890) (stn BS152), portion of hydrocladium. Scales: a–f, 0.5 mm.