Clytia tottoni ( Leloup, 1935 )

Galea, Horia R., 2010, Additional shallow-water thecate hydroids (Cnidaria: Hydrozoa) from Guadeloupe and Les Saintes, French Lesser Antilles, Zootaxa 2570, pp. 1-40 : 7-8

Clytia tottoni ( Leloup, 1935)

(fig. 2C–H)

? Clytia fragilis Congdon, 1907: 470 , fig. 13.― Nutting, 1915: 62, pl. 15 fig. 1.― Bennitt, 1922: 247.― Fraser, 1944: 137, pl. 24 fig. 109.― Deevey, 1954: 270.

Laomedea tottoni Leloup, 1935: 26 , figs 11, 12.―? Wedler, 1973: 34, fig. 4.―? Leloup, 1974: 21 fig. 17. not Laomedea (Phialidium) tottoni ― Vervoort, 1968: 17, fig. 6 [= Clytia linearis (Thornely, 1900) ].

Clytia laxa Fraser, 1937: 1 , pl. 1 fig. 1, syn. nov. ― Spracklin, 1982: 246, fig. 115B.— Calder, 1991: 64. Clytia arborescens ― Billard, 1906: 167.― Medel & Vervoort, 2000: 30, figs 7–8 (not Clytia arborescens Pictet, 1893: 33 , pl. 2 figs 28, 29).

? Obelia tottoni ― Park, 1998: 60, fig. 1.

Material examined. Stn.10: 19.11.2009, 17 m—several fertile colonies, to 4.5 cm high, on worm tubes and bivalve shell; 0 2.12.2009, 15–20 m— several fertile colonies, to 3 cm high, on various substrates such as sponge, stem of unidentified hydroid, bryozoan, dead gorgonian, and stylasterid (MHNG-INVE-68717). Stn.11: 30.11.2009, 15–18 m—fertile colonies, to 2 cm high, on dead tips of gorgonians and bivalve shells attached to them (part as MNHN-IK.2009-827).

Description. Colonies to 4.5 cm high, arising from root-like hydrorhiza; flaccid, do not stand up when out of water. Perisarc quite thick and horn-coloured in older parts, becoming thinner and transparent towards extremities. Stems branching irregularly to roughly alternate, mainly in one plane; with up to 4th order branches. Both stems and branches polysiphonic, grading to monosiphonic distally. Internodes in monosiphonic parts long, geniculate, slightly curved, with variable number of basal annuli. Hydrothecae borne terminally on variably annulated branchlets; deep-campanulate (510–705 µm long), thin-walled, with ca. 8–11 large, pointed, triangular cusps slightly inclined to one side (fig. 2E, G) and slightly projecting inwardly (fig. 2F, upper figure); diameter at aperture 220–305 µm; diaphragm transverse, 95–125 µm wide. Gonothecae arising from axils of branchlets; smooth-walled, long (730–920 µm), inverted-conical, tapering over most of length, maximum width 225–250 µm; constricted abruptly below rim, diameter at aperture 200– 220 µm; pedicel short and smooth; generally 3 medusa buds on blastostyle.

Remarks. Leloup (1935), followed Broch (1909) who recognized only two valid campanulariid genera, viz. Campanularia Lamarck, 1816 and Laomedea Lamouroux, 1812 , distinguishable by the structure of their hydrothecal diaphragms. He therefore considered that both Obelia fragilis Calkins, 1899 and Clytia fragilis Congdon, 1907 should be included in the Lamouroux’s genus, the latter species thus becoming a junior synonym of the former. The replacement name L. tottoni was then introduced for Congdon’s species.

However, the description and figure of Congdon’s material may apply to various species of Clytia Lamouroux, 1812 , and nothing indicates precisely that he actually had C. tottoni in his hands. His specimens were most probably monosiphonic despite their size (i.e. 12–18 mm high), a situation not met with in C. tottoni , which, according to the present material, forms polysiphonic stems in colonies higher than ca. 8 mm. Clytia fragilis was assigned to the synonymy of C. linearis (Thornely, 1900) by Calder (1991), but reinspection of the type material is necessary for a reliable identification. I therefore avoid including Congdon’s species in the synonymy and geographical records of C. tottoni .

The most confident identification of C. tottoni is, of course, that by Leloup (1935). His material clearly possessed polysiphonic colonies, the main distinguishing character of this species. On the other hand, Nutting (1915) and Wedler (1973) obtained only small, monosiphonic colonies, and their respective descriptions do not allow unambiguous identifications of their specimens. These records are here considered as doubtful. Calder (1991) assigned Vervoort’s (1968) material to C. linearis , and I agree. Equally doubtful are considered the Chilean record by Leloup (1974) and the Korean one by Park (1998), mainly on geographic grounds. Both may represent separate species with similar trophosome, but having different medusae.

The Caribbean Clytia laxa Fraser, 1937 corresponds in every respect to Leloup’s (1935) species, as well as the eastern Atlantic specimens assigned to Clytia arborescens Pictet, 1893 by Billard (1906) and Medel & Vervoort (2000). They are included here in the synonymy of C. tottoni .

Calder (1991) considered C. tottoni as a synonym of C. linearis , an opinion not shared here. Thornely’s (1900) species is always monosiphonic in habit and its hydrothecae are provided with longitudinal “keels” extending downwards from the cusp tips ( Lindner & Migotto 2002), a situation not met with in C. tottoni .

Caribbean records.? Puerto Rico ( Nutting 1915, as C. fragilis ), Dominican Republic ( Fraser 1937, as C. laxa ),? Colombia ( Wedler 1973), Belize ( Spracklin 1982).

World distribution. Bermuda ( Congdon 1907, Bennitt 1922, both as C. fragilis ),? Cape Hatteras ( Nutting 1915, Fraser 1944, both as C. fragilis ), Dry Tortugas ( Leloup 1935), Madeira ( Billard 1906; Medel & Vervoort 2000, both as C. arborescens ),? Chile ( Leloup 1974),? Korea ( Park 1998).