Clytia gracilis (M. Sars, 1850)

Gil, Marta & Ramil, Fran, 2025, Hydroids (Cnidaria, Hydrozoa) from Guinea Bissau, Zootaxa 5577 (1), pp. 1-89 : 31-32

Clytia gracilis (M. Sars, 1850)

Laomedea gracilis M. Sars, 1851: 138 .

Clytia gracilis : Picard, 1951a: 110.— Patriti, 1970: 33, fig. 40.— Ramil & Vervoort, 1992a: 235–238, fig. 67A.— Cornelius, 1995b: 246–248, fig. 56.— Medel & Vervoort, 2000: 32–34.— Schuchert, 2001: 151–152, fig. 131A–B.— Peña Cantero & García Carrascosa, 2002: 145–146, fig. 28A–B.

Laomedea sp. aff. gracilis : Broch, 1914: 37–38.

Laomedea gracilis : Buchanan, 1957: 358–359.— Redier, 1965: 372.

Laomedea (Phialidium) pelagica : Vervoort, 1959: 313–315, fig. 55B–C.

Material examined. BISSAU-0810, stn BS152, 10º31'12"– 10º30'19"N, 17º12'34"– 17º12'32"W, 300–305 m, 27-X-2008: nine colonies without gonothecae, of which six growing on Lytocarpia myriophyllum , one on Turritopsis sp. , one on Lafoea gracillima and one on Aglaophenia lophocarpa .

BISSAU-0810, stn BS191, 10º18'25"– 10º19'20"N, 16º08'47"– 16º08'47"W, 24–25 m, 3-XI-2008: 219 colonies (90 with gonothecae), 16–19 mm high, of which 34 growing on Idiellana pristis , 33 on bryozoans, 31 on Eudendrium capillare , 26 on crustaceans, 14 on Diphasia digitalis , 10 on unidentified hydroids, four on Bimeria vestita , two on Tridentata loculosa , two on bivalves, one on Eudendrium ramosum , one on Halecium marocanum , one on Tridentata marginata , one on a worm tube, and one on a rope.

BISSAU-0810, stn BS192, 10º19'30"– 10º20'15"N, 16º10'27"– 16º10'59"W, 24 m, 3-XI-2008: three colonies without gonothecae, up to 22 mm high, of which one growing on Idiellana pristis and another one on a crustacean.

BISSAU-0810, stn BS193, 10º21'13"– 10º21'51"N, 16º10'17"– 16º10'56"W, 20–21 m, 3-XI-2008: 14 colonies (seven with gonothecae), growing on bryozoans.

BISSAU-0810, stn BS194, 10º21'59"– 10º22'36"N, 16º13'23"– 16º14'03"W, 21–24 m, 3-XI-2008: 10 colonies (five with gonothecae), up to 5 mm high, of which seven growing on bryozoans, two on Idiellana pristis and one on Eudendrium ramosum .

BISSAU-0810, stn BS195, 10º22'44"– 10º23'22"N, 16º15'37"– 16º16'18"W, 29 m, 3-XI-2008: 21 colonies (12 with gonothecae), of which seven growing on bryozoans, three on Idiellana pristis , one on Diphasia digitalis , one on Tridentata marginata and one on a crustacean.

BISSAU-0810, stn BS216, 10º30'53"– 10º31'39"N, 16º31'33"– 16º32'02"W, 56–58 m, 7-XI-2008: eight colonies without gonothecae, of which seven growing on Halecium beanii .

BISSAU-0810, stn BS226, 11º22'11"– 11º21'55"N, 17º02'30"– 17º01'54"W, 35–37 m, 9-XI-2008: one colony without gonothecae, growing on Sertularelloides cylindritheca .

CCLME-1205, stn BT318, 10º41'43"– 10º43'12"N, 16º48'37"– 16º48'55"W, 107 m, 18-V-2012: one colony 109 mm high without gonothecae, growing on a bivalve.

Remarks. Our material conforms to that described by Ramil &Vervoort (1992a). Deep, campanulate hydrothecae with acute, inwardly curved marginal cups inclined to one side, and urn-shaped, distally-truncate gonothecae, are diagnostic features of this species.

Biology. Clytia gracilis is a common epibiont of other hydroids, being also found on rocks and pebbles, algae, sponges, bryozoans, mollusk shells, mollusk eggs, worm tubes and barnacles ( Peña Cantero & García Carrascosa 2002). In the northern hemisphere, gonothecae have been found from April to December ( Peña Cantero & García Carrascosa 2002; Gil & Ramil 2017a).

In our material, it was found growing on hydroids, crustaceans, bryozoans, worm tubes and bivalves. Gonothecae were found in November.

Distribution. Clytia gracilis is a circumglobal species in temperate and tropical waters ( Calder 2013), and it is widely distributed in the East Atlantic, from England to South Africa ( Medel & Vervoort 2000; Galea 2007). In West Africa, it has been recorded from Morocco ( Patriti 1970; Ramil & Vervoort 1992a), Mauritania ( Medel & Vervoort 2000; Gil & Ramil 2017a), Guinea-Bissau [ Vervoort 1959, as L. (Phialidium) pelagica ], the Republic of Guinea [ Picard 1951a; Vervoort 1959, as L. (Phialidium) pelagica ], the Ivory Coast ( Redier 1965, as L. gracilis ), Ghana [ Buchanan 1957, as L. gracilis ; Vervoort 1959, as L. (Phialidium) pelagica ], Cameroon, Angola ( Broch 1914, as Laomedea sp. aff. gracilis ) and the Vema Seamount ( Gil & Ramil 2021b). Its bathymetric distribution ranges from 0 ( Peña Cantero & García Carrascosa 2002) to 1443 m ( Schuchert 2001).

Our material was collected at depths between 20–305 m.