Tridentata rugosissima ( Thornely, 1904 )

Gil, Marta & Ramil, Fran, 2025, Hydroids (Cnidaria, Hydrozoa) from Guinea Bissau, Zootaxa 5577 (1), pp. 1-89 : 55

Tridentata rugosissima ( Thornely, 1904)

( Fig. 9E )

Sertularia rugosissima Thornely, 1904: 118 , pl. II fig. 4.— Broch, 1914: 34–36, fig. 9a–c.— Migotto, 1996: 75–78, fig. 14d–e.— Galea, 2008: 36 , fig. 6l–m.— Moura, 2020: 104–105, fig. 21k.

Tridentata rugosissima : Calder, 2020: 222, fig. 6g.— Calder & Faucci, 2021: 35–36 , fig. 10d.— Gil & Ramil, 2023b: 430–431, fig. 4E.

Geminella subtilis : Vannucci Mendes, 1946: 572, pl. 4 figs 42–43.

Sertularia subtilis : Cooke, 1975: 99–100, pl. 4 fig. 3.

Material examined. BISSAU-0810, stn BS191, 10º18'25"– 10º19'20"N, 16º08'47"– 16º08'47"W, 24–25 m, 3-XI-2008: one colony without gonothecae, growing on a bryozoan.

BISSAU-0810, stn BS193, 10º21'13"– 10º21'51"N, 16º10'17"– 16º10'56"W, 20–21 m, 3-XI-2008: 11 colonies without gonothecae, 4–9 mm high, all growing on bryozoans.

Remarks. Our material is consistent with that described by Gil & Ramil (2023b), and represents the first record of T. rugosissima for Guinea-Bissau.

Biology. This species has been found growing on hydrozoans, bryozoans and algae ( Vannucci Mendes 1946; Migotto 1996; Galea 2008). In the northern hemisphere, fertile colonies have been found but no data information is given ( Cooke 1975), while in the southern hemisphere, they have been found in April ( Vannucci Mendes 1946).

Our colony was found growing on a bryozoan. Gonothecae were not observed.

Distribution. Tridentata rugosissima has a circumtropical distribution ( Migotto 1996). In West Africa, it has been recorded from the Republic of Guinea ( Gil & Ramil 2023b) and Ghana ( Broch 1914). Its bathymetric distribution ranges from 0 ( Galea 2008) to 26 m ( Gil & Ramil 2023b).

Our material was collected at depths between 20–25 m.

Figures

FIGURE 9.A. Tridentata loculosa (Busk, 1852) (stn BS199), portion of stem. B–D. Tridentata marginata (Kirchenpauer, 1864) (stn BS195); portion of colony (B); gonothecae (C–D). E. Tridentata rugosissima (Thornely, 1904) (stn BS193), portion of stem. F. Tridentata turbinata (Lamouroux, 1816) (stn BS191), portion of stem. Scales: a–f, 0.5 mm.