Clytia linearis ( Thornely, 1900 )

Calder, Dale R., 2013, Some shallow-water hydroids (Cnidaria: Hydrozoa) from the central east coast of Florida, USA, Zootaxa 3648 (1), pp. 1-72 : 55

Clytia linearis ( Thornely, 1900)

Fig. 15f

Obelia linearis Thornely, 1900: 453 , pl. 44, fig. 6.

Type locality. Papua New Guinea: New Britain, Blanche Bay ( Thornely 1900) .

Voucher material. Off St. Lucie Inlet, 27°10.7’N, 80°02.7’W, on Eudendrium carneum , 23 m, vii.1975, Johnson-Sea-Link, JSL 274, fragments of one colony, up to 9 mm high, without gonophores, coll. T. Askew, ROMIZ B3983 .

Remarks. Comments are warranted on nomenclature of Clytia linearis ( Thornely, 1900) . Leloup (1935) referred Obelia fragilis Calkins, 1899 and Clytia fragilis Congdon, 1907 to the genus Laomedea Lamouroux, 1812 . To remove supposed homonymy between the two when thus assigned, he proposed C. tottoni as a substitute name for Congdon’s species. However, no homonymy currently exists because the two species are now assigned once again to Obelia Péron & Lesueur, 1810 and Clytia Lamouroux, 1812 , respectively, where they are considered synonyms of other species ( Cairns et al. 2002). In being a replacement name for C. fragilis Congdon, 1907 , the name C. tottoni Leloup, 1935 is by definition a junior objective synonym of it, having the same name-bearing type (ICZN Art. 67.8, 72.7). In turn, both binomena are considered here to be junior subjective synonyms of C. linearis , as discussed earlier ( Calder, 1991a). If Atlantic and Pacific populations are ever shown to be different species, however, the name C. fragilis will need to be resurrected for the former.

It is improbable that Leloup’s (1935) species, discussed under the name Laomedea tottoni , is the same as Congdon’s Clytia fragilis , i.e., I believe he misidentified his hydroid. Indeed, it seems much more like C. laxa Fraser, 1937b in lacking the prominent pleat extending down from each marginal cusp and in being polysiphonic rather than monosiphonic (or even partly stolonal). Hydroids from Guadeloupe recently described by Galea (2010) as Clytia tottoni also resemble C. laxa . In summary, the binomen C. tottoni is a junior objective synonym of C. fragilis (considered here a junior synonym of C. linearis ), while Leloup’s C. tottoni was in fact a different species, likely identical to C. laxa . Hydroids reported as C. laxa by Nelson et al. (1994) from artificial reefs off Vero Beach, Florida, are assumed here to have been correctly identified and not based on C. linearis .

Discussion of C. linearis , based on material from Bermuda (type locality of C. fragilis ), is given in an earlier work ( Calder 1991a). Lindner & Migotto (2002) provided additional information on the species, including development of its medusa stage.

Reported distribution. Atlantic coast of Florida. First record.

Western Atlantic. Cape Hatteras ( Nutting 1915, as Clytia fragilis Congdon, 1907 ) to Brazil (Oliveira et al. submitted), including Bermuda ( Calder 1991a), the Gulf of Mexico ( Calder & Cairns 2009), and the Caribbean Sea ( Calder & Kirkendale 2005).

Elsewhere. Circumglobal in shallow warm waters ( Lindner & Migotto 2002).

Figures

FIGURE 15. a, Campanularia macroscypha: part of colony with hydrotheca, ROMIZ B1101, scale equals 0.5 mm. b, Campanularia macroscypha: hydrotheca and distal part of pedicel, ROMIZ B1101, scale equals 0.20 mm. c, Orthopyxis sargassicola: hydrotheca and distal part of pedicel, ROMIZ B1123, scale equals 0.20 mm. d, Orthopyxis sargassicola: gonotheca, ROMIZ B1123, scale equals 0.20 mm. e, Clytia elsaeoswaldae: part of a colony with hydrotheca and gonotheca, ROMIZ B1134, scale equals 0.25 mm. f, Clytia linearis: hydrotheca and distal part of pedicel, ROMIZ B3983, scale equals 0.25 mm.