Clytia gracilis (Sars, 1850)

Castro Mendonça, Luana M., Parisotto Guimarães, Carmen R. & Haddad, Maria A., 2022, Taxonomy and diversity of hydroids (Cnidaria: Hydrozoa) of Sergipe, Northeast Brazil, Zoologia (e 21032) 39, pp. 1-65 : 18-22

Clytia gracilis (Sars, 1850)

Fig. 8E–F

Synonyms available from: Calder (1991).

Laomedea gracilis M. Sars, 1850: 138 [part] [not Lomedea (sic) gracilis Dana, 1846 , a name suppressed for both the Principle of Priority and the Principle of Homonymy (Opinion 1465)].

Clytia attenuate Fraser 1938a ; – Vannucci Mendes 1946, – Vannucci 1949; 1951a.

? Thaumantias raridentata – Vannucci 1951a, 1951b, 1954 [polyp];

Description: Colonies mainly stolonal but sometimes erect, up to 1.8 mm high, arising from a creeping hydrorhiza. Erect colonies with few and irregular branches. Stem monosiphonic, with each ramification arising slightly curved and giving rise to another ramification or a pedicel with hydrothecae. Perisarc smooth, annulated in the stem base, in each ramification, and less frequently in the medial and distal portion of pedicels and before the hydrothecae. Some polyps with pedicels covered by algae. Hydrothecae cylindrical, 0.6–1.1 mm high, 0.28–0.67 mm wide at the margin. Diaphragm thin, straight, near hydrothecal base. Margin with 6–10 sharp cusps, generally slightly curved to the left, with U-shaped embayments between cusps. Gonothecae urn-shaped, 0.57–1.9 mm high, 0.32–1.1 mm wide, arising from hydrorhiza or on short annulated pedicels connected with the pedicels with hydrothecae.

Material examined: PCS – abundant colonies with and without gonothecae, from the dry and rainy seasons. VB – abundant colonies, few with gonothecae, from dry and rainy season; SE – few colonies, one with gonothecae, from the dry and rainy season. CZUFS CNI-00002; CNI-00048; CNI-00105; CNI-00107; CNI-00108; CNI-00109; CNI-00110.

Stations: PCS – 1, 3, 4, 5, 6, 8, 9, 11, 12, 13, 14, 15 e 18; VB – C1P12, C1P34, C1P56, C2P12, C2P34 rep, C2P56, C3P12, C3P34, C3P56; SE – C1P12,´C1P34, C1P56, C2P12, C2P34, C2P56, C3P12, C3P34.

Bottom: gravel and mud.

Distribution: Brazil – Ceará ( Marques et al. 2006), Pernambuco ( Calder and Maÿal 1998, Oliveira et al. 2009, abstract), Bahia ( Grohmann et al. 2003, Kelmo and Attrill 2003), Rio de Janeiro ( Grohmann et al. 2011), São Paulo ( Marques et al. 2011, Oliveira et al. 2006, Cunha and Jacobucci 2010, Oliveira and Marques 2011, Silveira and Morandinin 2011, Fernandez et al. 2014, 2015), and Paraná ( Bouzon et al. 2012). World distribution – circumglobal, including subpolar regions ( Galea 2008).

Remarks: The PCS material was colonizing rocks, algae, Bryozoa, Ascidiacea, and a thyroscyphid hydroid. Estuarine material found on plates, algae, Bryozoa, Ostreidae , polychaetes tubes, barnacle (Cirripedia), Amphipoda leg, Ascidiacea, and the hydroids Bougainvillia muscus , Cladocoryne floccosa , Corydendrium parasiticum , Ectopleura dumortierii , Eudendrium merulum , Nemalecium lighti , Pennaria disticha , and Plumularia floridana .

Clytia hemisphaerica (Linnaeus, 1767) Fig. 8B

Synonyms available from: Calder (1991).

Medusa hemisphaerica Linnaeus, 1767: 1098 [medusa].

Description: Colonies stolonal, up to 2.1 mm high, arising from a creeping hydrorhiza. Pedicels long and with a thin and smooth perisarc, annulated and/or waved along their entire length or with an annulus at the base and a distal end or, less frequent, in the medial portion of the pedicel. Some colonies with pedicels covered by algae. Hydrothecae cylindrical, 0.38–0.42 mm high, 0.26–0.4 mm of wide at the margin. Diaphragm thin, straight, and near hydrothecal base. Margin with 9–11 short cusps, straight, rounded, or sharp, with U-shaped embayments between cusps. Gonothecae pot-shaped, 0.51–0.66 mm high, 0.26–0.4 mm maximal width, arising from the hydrorhiza in short pedicels. Gonothecal wall waved along its whole length.

Material examined: PCS – one colony with gonothecae from the rainy season. CZUFS CNI-00111.

Station: PCS – 5.

Bottom: sand.

Distribution: Brazil – Pernambuco ( Oliveira et al. 2009, abstract), Sergipe (medusa, as Phialidium hemisphaericum, Araújo 2006 ), Bahia (Kelmo and Attrill 2003), Espírito Santo ( Grohmann et al. 1997, 2003), Rio de Janeiro ( Nogueira et al. 1997), São Paulo ( Silveira and Morandini 2011), and Paraná (Maria A. Haddad unpub. data). World distribution – considered cosmopolitan in coastal regions ( Cornelius 1995b).

Taxonomic remarks: Clytia hemisphaerica is probably a species complex ( Boero 2002). There is a discussion about the real distribution of this species in the world and South America. However, the reproductive structure is still considered specific to C. hemisphaerica . Phylogenetic analysis also shows that C. hemisphaerica forms a clade with C. elsaeoswaldae and two morphotypes of C. gracilis ( Lindner et al. 2011) . New studies are needed to highlight the real distribution of this species and also to figure out if C. hemisphaerica is a species complex and which species could be part of this. While these issues are not resolved, the Brazilian records will be considered valid here.

Remarks: Found on algae.

Figures

Figure 8. (A) Campanularia sp. 1: general view of a polyp; (B) Clytia hemisphaerica: general view of polyps and two gonothecae (red arrows); (C) Clytia elsaeoswaldae: general view of two polyps and a gonotheca (red arrows); (D, G) Campanularia sp. 2: (D) general view of a polyp; (G) detail of the hydrotheca; (E-F) Clytia gracilis: (E) general view of two polyps and two gonothecae (red arrows); (F) general view of a polyp.