Clytia linearis ( Thornely, 1900 )

Gil, Marta & Ramil, Fran, 2025, Hydroids (Cnidaria, Hydrozoa) from Guinea Bissau, Zootaxa 5577 (1), pp. 1-89 : 32-33

Clytia linearis ( Thornely, 1900)

( Fig. 5C–D )

Obelia linearis Thornely, 1900: 453 , pl. 44 fig. 6. Clytia linearis : Calder, 1991: 62–64, fig. 34.— Ramil & Vervoort, 1992a: 238–239, fig. 67b.— Altuna, 1994a: 60–65, figs 1,

2.— Migotto, 1996: 85–86, fig. 16A–B.— Medel & Vervoort, 2000: 38–39.— Peña Cantero & García Carrascosa, 2002:

149–152, fig. 28 e–f.— Calder, 2013: 55, fig. 15F. Clytia gravieri : Millard, 1975: 215–217, fig. 71F–H.— Marinopoulos, 1981: 176.

Material examined. BISSAU-0810, stn BS191, 10º18'25"– 10º19'20"N, 16º08'47"– 16º08'47"W, 24–25 m, 3-XI-2008: four colonies 25 mm high with gonothecae, of which one growing on a crustacean.

BISSAU-0810, stn BS193, 10º21'13"– 10º21'51"N, 16º10'17"– 16º10'56"W, 20–21 m, 3-XI-2008: one colony, 20 mm high without gonothecae, growing on a bryozoan.

BISSAU-0810, stn BS195, 10º22'44"– 10º23'22"N, 16º15'37"– 16º16'18"W, 29 m, 3-XI-2008: one colony, 9 mm high without gonothecae, growing on Idiellana pristis .

Remarks. Although gonothecae were not found, the presence of perisarcal ridges running downward from the hydrothecal along the hydrothecal wall is diagnostic of this species ( Ramil & Vervoort 1992a). Our material represents the first record of this species for Guinea-Bissau.

Biology. Clytia linearis colonizes a great variety of substrates, usually algae and other hydroids, but also rocks, bio-concretions, seagrasses, sponges, anthozoans, bryozoans, worm tubes, mollusks and barnacles ( Peña Cantero & García Carrascosa 2002). In the northern hemisphere, gonothecae have been found in January, April, May and between June and November ( Altuna 1994a; Peña Cantero & García Carrascosa 2002), while in the southern hemisphere, fertile colonies were found in March and April ( Migotto 1996).

In our material, some colonies were found growing on crustaceans, bryozoans and on the hydroid I. pristis . Gonothecae were found in November.

Distribution. This species has a circumtropical distribution ( Ramil & Vervoort 1992a; Calder 2013) and it is considered a Lessepsian migrant in the Mediterranean by Boero et al. (2005). In West Africa, it has been collected from Morocco ( Ramil & Vervoort 1992a) and the Cape Verde Islands ( Medel & Vervoort 2000). Its bathymetric distribution ranges from 0 ( Peña Cantero & García Carrascosa 2002) to 200 m ( Marinopoulos 1981).

Our material was collected at depths between 20–29 m.

Figures

FIGURE 5. A–B. Orthopyxis mollis (Stechow, 1919) (stn BS194): portion of colony with hydrotheca and two gonothecae (A); portion of colony with two hydrothecae (B). C–D. Clytia linearis (Thornely, 1900) (stn BS191); hydrotheca (C); gonotheca (D). E–F, Laomedea calceolifera (Hincks, 1871) (stn BS131); hydrotheca (E); female gonotheca (F). Scales: a–f, 0.5 mm.