Synthecium tubithecum (Allman, 1877)

(fig. 6A–C)

Sertularia tubitheca Allman, 1877: 24, pl. 16 figs 5, 6.― Fewkes, 1881: 128.― Nutting, 1895: 88.

Synthecium tubithecum ― Jäderholm, 1903: 291, pl. 13 fig. 7.― Nutting, 1904: 134, pl. 41 fig. 1.― Leloup, 1935: 33.― Fraser, 1944: 237, pl. 49 fig. 222.― Vannucci, 1950: 86, pl. 1 fig. 4.― Vannucci, 1951: 83.― Mayal, 1983: 5, figs 1, 2.― Calder, 1991: 84, figs 44, 45.― Calder & Kirkendale, 2005: 484.

Synthecium tubitheca ― Vervoort, 1968: 30, fig. 13A, B.

Synthecium rectum Nutting, 1904: 135, pl. 41 fig. 2.― Fraser, 1944: 235, pl. 49 fig. 220.

Synthecium nanum Fraser, 1943: 80, pl. 18 fig. 10.

Synthecium (?) nanum ― Fraser, 1944: 235, pl. 48 fig. 219.

Material examined. Stn.9: 21.11.2009, 21 m—several sterile fragments to 1.5 cm high, some branched, on sponge (MNHN-IK.2009-825). Stn.10: 19.11.2009, 17 m—a sterile, branched stem, 1.2 cm high, on concretions (MHNG-INVE-68726). Stn.11: 30.11.2009, 15–18 m—dense colony on sponge, with stems to 1.2 cm high, some branched and some bearing male gonothecae (part as MHNG-INVE-68727).

Remarks. For a description of this species, see Calder (1991). Two types of capsules occur in the present material: small microbasic mastigophores (6.3–6.6 × 1.8–2.0 µm) and large (?) macrobasic mastigophores (40.0–42.5 × 10.7–11.5 µm).

Caribbean records. See Calder & Kirkendale (2005).

World distribution. Dry Tortugas (Allman 1877; Nutting 1904; Leloup 1935; Fraser 1944, as S. nanum), Bahamas (Nutting 1895), W of Florida (Albatross Stn. 2410, 2413, and 2414) (Nutting 1904, as S. tubithecum), off South Carolina [Nutting 1904, as S. tubithecum (Albatross Stn. 2311) and S. rectum (Albatross Stn. 2416)], off La Havana [Nutting 1904, as S. tubithecum (Albatross Stn. 2331) and S. rectum (Bahama Expedition)], Brazil (Vannucci 1950, 1951; Mayal 1983), Bermuda (Calder 1991).