Hydromedusae observed during night dives in the Gulf Stream Author Schuchert, Peter Muséum d’histoire naturelle, C. P. 6434, CH- 1211 Genève 6, Switzerland peter.schuchert@ville-ge.ch Author Collins, Richard 880 NE 33 rd Street, Boca Raton, Florida, USA rc6684@icloud.com text Revue suisse de Zoologie 2021 2021-10-21 128 2 237 356 journal article 3356 10.35929/RSZ.0049 172fa5c5-c0c4-4bd7-b710-d608237b8458 0035-418 5639938 8382D1CA-7C0E-4B1C-9591-4CEAA2F296FB Liriope tetraphylla ( Chamisso & Eysenhardt, 1821 ) Fig. 62 Geryonia tetraphylla Chamisso & Eysenhardt, 1821: 357 , pl. 27 fig. 2. Liriope tetraphylla . – Russell, 1953: 419 , figs 275-282, pl. 24 fig. 2. – Kramp, 1959a: 193 , fig. 293. ‒ Kramp, 1961: 239 . – Kramp, 1968: 122 , fig. 333. – Pagès et al. , 1992: 43 , fig. 52. ‒ Nagata et al., 2014: 315 , figs 34-35. For a complete synonymy see Russell (1953) . Examined material: BFLA4026 ; 1 specimen ; 15-FEB- 2019 ; size 20 mm ; preserved in alcohol for DNA extraction; 16S sequence MW528649 . MHNG-INVE-0031754; Mediterranean , Bay of Villefranche-sur-Mer ; 43.6860°N 7.3170°E ; 70 m depth; collection date 11-MAY-2001 ; > 2 specimens ; size 3-4 mm ; 1 preserved in formalin, others in ethanol for DNA extraction; 16S sequence MW528628 . Observations: Specimen from Florida with nearly hemispherical bell, 20 mm wide, apical jelly thick, with long, thin gastric peduncle, peduncle length more than two times the bell height. Thin nematocysts tracks on exumbrella, four perradial and four interradial, interradial ones reaching only to base of short tentacles, perradial ones longer. Stomach on long gastric peduncle, relatively small, four indistinct perradial lips. Radial canals four, centripetal canals not visible on photos. Gonads very wide, flat, leaf-like, heart-shaped with pointed side pointing toward periphery. Four long perradial tentacles originating at bell margin, with ring-shaped nematocyst clusters. Four short interradial tentacles originating above bell margin on exumbrella, with adaxial nematocyst clusters. 16S Data: A blastn search in GenBank with the 16S from Florida ( MW528649 ) yielded numerous matches with other Liriope tetraphylla samples, but only with identities from 92 to 95.5%. The sequence obtained from the Mediterranean specimen ( MW528628 ) gave identities from 90 to 99 % with other Liriope tetraphylla sequences. Distribution: In Pacific, Indian, and Atlantic ocean, including the Mediterranean, approximately between 40°N and 40°S , in the NE Atlantic reaching to the English Channel (Kramp, 968). Type locality: Indian Ocean ( Chamisso & Eysenhardt, 1821 ). Remarks: This is a rather unproblematic species, but Collins et al. (2008) suggested the existence of cryptic species based on significant divergences in mitochondrial 16S and nuclear sequence data. The high 16S divergences were confirmed in the present study.