Additional shallow-water thecate hydroids (Cnidaria: Hydrozoa) from Guadeloupe and Les Saintes, French Lesser Antilles Author Galea, Horia R. text Zootaxa 2010 2570 1 40 journal article 10.5281/zenodo.197380 623f5942-0074-4d90-b034-a0b102d5a3e6 1175-5326 197380 Sertularia tongensis ( Stechow, 1919 ) (fig. 5H–M, table 2) Sertularella tongensis Stechow, 1919 : 89 , fig. F1, G1.― Vervoort & Vasseur, 1977 : 52 , fig. 23. not Sertularia tongensis Stechow, 1919 : 101 , fig. N1 (= Sertularia ephemera nom. nov. ). Sertularia thecocarpa Jarvis , 1922 : 341 , pl. 24 fig. 10, syn. nov. ― Millard & Bouillon, 1973 : 71 , fig. 9C–D.― Morri et ., 2009 : 54 , figs 2E–F, 4 A–D. Sertularella minuscula Billard, 1924 : 648 , fig. 2F, syn. nov. ― Billard, 1925 : 139 , fig. 9.― Leloup, 1932 : 161 , figs 26, 27.― Leloup, 1935 : 45 .― Fraser, 1944 : 266 , pl. 57 fig. 254.― Pennycuik, 1959 : 195 , pl. 6 fig. 2.―Van Gemerden- Hoogeveen, 1965 : 34 , figs 8–12.―Hirohito, 1974: 18, fig. 7.― Cooke, 1975 : 98 .― Gibbons & Ryland, 1989 : 417 , fig. 33.― Watson, 2002 : 343 , fig. 3. Sertularella parvula Mammen, 1965 : 37 , fig. 69, syn. nov. (not Calamphora parvula Allman, 1888 ). Sertularia stechowi Hirohito, 1995: 215 , figs 72D–F, 73A–C, pl. 12 fig. C, syn. nov. Sertularella cumberlandica ― Stechow, 1913 : 140 , fig. 115 [not Sertularella (= Symplectoscyphus ) cumberlandica Jäderholm, 1905 ]. Symplectoscyphus cumberlandicus ― Yamada, 1959 : 60 [not Symplectoscyphus cumberlandicus ( Jäderholm, 1905 ) ]. Material examined . Stn.9 : 21.11.2009 , 21 m—several sterile stems to 7 mm high, on concretions and stem of Eudendrium sp. (MNHN-IK.2009-818). Stn.10 : 19.11.2009 , 17 m—several stems to 7 mm high, of which one bears a gonotheca and another two side branches, on sponge; 0 2.12.2009 , 15–20 m—several sterile stems, to 9 mm high, on sponge and Dictyota sp. (MHNG-INVE-68724) Stn.12 : 30.11.2009 , 12–15 m—several sterile stems, to 6 mm high, on sponge and worm tube. TABLE 2 . Comparative measurements of Sertularia tongensis (Stechow, 1919) , in µm.

Jarvis (1922), as Sertularella thecocarpa	Billard (1925), as Sertularella minuscula	van Gemerden- Hoogeveen (1965), as Sertularella minuscula	Millard & Bouillon (1973), as Sertularella thecocarpa	Hirohito (1974), as Sertularella minuscula
Internode
- length	270–340	230–630	105–175	–	300–350
- diameter at node	–	80–115	60–110	–	–
Hydrotheca
- free adcauline side	230–260	170–250	170–235	140–280	210–230
- adnate adcauline side	170–200	150–180	105–190	160–210	170–180
- abcauline side	230–285	230–330	200–280	270–300
- diameter at aperture	120–140	105–115	105–125	120–150	110–120
Gonotheca
- length	950	–	1060–1220	830	700–850 (3)
- max. width	800	–	575–720	530	500–550 (3)

contiuned.

Gibbons & Ryland (1989), as Sertularella minuscula	Hirohito (1995), as Sertularia stechowi	Morri et al . (2009), as Sertularia thecocarpa	Present study, as Sertularia tongensis
Internode
- length	–	–	400–420	350–490
- diameter at node	–	–	100–120	50–80
Hydrotheca
- free adcauline side	330–480	–	250–280	135–325
- adnate adcauline side	110–165	–	170–180	135–175
- abcauline side	200–325	300–370	300–310	190–390
- diameter at aperture	80–105	100–140	150–160	100–115
Gonotheca
- length	–	900–1050	600–700	760
- max. width	–	550–650	400–450	505

Remarks . This remarkable hydroid is characterized by: 1) its alternate hydrothecae (fig. 5H), instead of (sub)opposite as in the majority of species assigned to Sertularia Linnaeus, 1758 ; 2) a hydrothecal aperture closed by two peculiar opercular flaps, both pleated along a median line, giving the impression of a fourflapped operculum when the hydrotheca is seen apically (fig. 5K); 3) its gonothecae (fig. 5L) and, when present, side branches (fig. 5I ) arising from within the stem hydrothecae. In spite of its peculiar morphology, four additional nominal species from the Indo-Pacific have been erected for the present hydroid, viz . Sertularia thecocarpa Jarvis , 1922 , Sertularella minuscula Billard, 1924 , Sertularella parvula Mammen, 1965 , and Sertularia stechowi Hirohito, 1995 . All the available descriptions and illustrations referring to them leave no doubt about their conspecificity with Stechow’s (1919) species. Comparison of measurements from various sources (table 2) show that all fall into a common range of variation. The length of both abcauline and free adcauline sides of the hydrotheca appears highly variable and is in relation to whether the renovations (sometimes numerous, though often inconspicuous) have been included when measuring the size of the thecae. The differences in the size of the gonotheca may be due to different stages of maturation and/or to possible sexual dimorphism, though their shape is substantially the same in all the available accounts. Two types of nematocysts occur in the present material (undischarged capsules): microbasic mastigophores (6.1–6.4 × 1.8–2.0 µm), and larger, unidentified capsules (10.8–11.4 × 3.1–3.3 µm). Since Sertularella tongenis Stechow, 1919 clearly belongs to Sertularia Linnaeus, 1758 (see SEM images in Morri et al . 2009 ), it appears that this species and Sertularia tongensis Stechow, 1919 become secondary homonyms. As Sertularella tongensis was described on p. 89, and Sertularia tongensis on p. 101 of the same publication ( Stechow 1919 ), I consider the former specific name as the senior homonym (ICZN Art. 24.2, Principle of the First Reviser), and I propose the new name Sertularia ephemera nom. nov. for the latter (ICZN Art. 60). Better knowledge of the taxonomical status of Sertularia ephemera is actually needed, especially with respect to its relationship with S. maldivensis ( Borradaile, 1905 ) . Caribbean records . Bonaire ( Leloup 1935 , Van Gemerden-Hogeveen 1965 ), Farallón Centinela ( Venezuela ) ( Van Gemerden-Hoogeveen 1965 ). World distribution . Kingdom of Tonga ( Stechow 1919 ), Chagos Archipelago ( Jarvis 1922 ), Indonesia ( Billard 1924 , 1925 ), Gulf of Manaar ( Leloup 1932 ), Queensland ( Australia ) ( Pennycuik 1959 , Watson 2002 ), southern India ( Mammen 1965 ), Seychelles ( Millard & Bouillon 1973 ), Bonin Islands (Hirohito 1974), Marshall Islands ( Cooke 1975 ), Moorea ( Vervoort & Vasseur 1977 ), Fiji ( Gibbons & Ryland 1989 ), Japan ( Stechow 1913 , Yamada 1959 , Hirohito 1995), Levant Sea ( Morri et al . 2009 ).