Cyclocanna producta (G.O. Sars, 1874 )

Gil, Marta & Ramil, Fran, 2023, The genera Egmundella Stechow, 1921 and Cyclocanna Bigelow, 1918 (Cnidaria, Hydrozoa) in waters of Northwest Africa, Zootaxa 5264 (4), pp. 490-504 : 500-502

Cyclocanna producta (G.O. Sars, 1874)

( Fig. 6 ; Table 5)

Cyclocanna producta — Schuchert et al., 2017: 177 , fig. 7.

Lovenella producta — Fraser, 1944: 175, pl. XXXI fig. 149; Cornelius, 1995: 166–168, fig. 37; Schuchert, 2001: 54, fig. 39; Calder, 2012: 22–23 , fig. 21.

Egmundella producta — Schuchert, 2016: 219–224 , figs 1A–D, 2A–C, 3A–F.

Material examined. Morocco. MAROC-0411, stn MO31, 34º28′56″– 34º27′33″N, 7º12′22″– 7º11′02″W, 1722– 1824 m, 24-XI-2004: a colony, 4 mm high, growing on Halecium delicatulum , without gonothecae .

MAROC-0411, stn MO56, 33º32′05″– 33º31′60″N, 8º26′43″– 8º28′34″W, 1556–1620 m, 02-XI-2004: two colonies, 1–5 mm high, one growing on Halecium delicatulum , the other on Stegolaria geniculata ; both without gonothecae.

Western Sahara. MAROC-0611, stn MO189, 21º09′04″– 21º12′24″N, 17º42′06″– 17º42′18″W, 556–564 m, 14- XI-2004: a colony, 1.9 mm high, growing on an unidentified hydrozoan, without gonothecae .

MAROC-0611, stn MO235, 23º12′00″– 23º14′27″N, 17º11′16″– 17º12′27″W, 909–913 m, 27-XI-2006: a colony, 0.6 mm high, growing on Halecium sp , without gonothecae.

MAROC-0611, stn MO260, 24º31′21″– 24º33′03″N, 16º51′04″– 16º48′12″W, 1429–1440 m, 05-XII-2006: a colony, 4 mm high, growing on Lafoea gracillima , without gonothecae.

Mauritania. MAURIT-0811, stn MU89 , 20 º20′50″– 20º18′23″N, 17º53′30″– 17º52′03″W, 1012– 1000 m, 20-XI-2008: three colonies up to 4 mm high, one growing on Eudendrium ramosum , another on an unidentified hydrozoan, and the last one on a plastic net; all with gonothecae .

MAURIT-0911, stn MU195 , 20 º24′31″– 20º26′10″N, 18º03′31″– 18º06′10″W, 1236– 1214 m, 23-XI-2009: two colonies growing on bivalves, without gonothecae .

Guinea Bissau. CCLME 2011-410 , stn GR- 04, 10º26′47′′N, 17º22′43′′W, 504 m, 28-X-2011: a colony growing on a worm tube, without gonothecae.

Description. Colonies stolonal, with hydrothecae, nematothecae and gonothecae arising irregularly from filiform hydrorhiza. Hydrothecae borne on long, smooth pedicels, with some short basal undulations and some others irregularly-placed along its length. Hydrotheca deeply campanulate, elongated, tapering basally where it is provided with a transverse, thin diaphragm; walls parallel, widening distally, rim not apparent, aperture closed by a conical operculum composed of 10–12 triangular flaps that can be folded either inwards or outwards, and in this case, the rim is distinctly-marked. Nematothecae arising between the hydrothecae, egg-shaped, borne on short pedicels, aperture apical, circular.

Gonothecae fan-shaped, strongly flattened “dorso-ventrally”, borne on short, slightly undulated pedicels, aperture distal, large, spanning from one side to the other.

Biology. This species has been found growing on various hydroids, notably Tubularia indivisa Linnaeus, 1758 ( Calder 2012) , dead Lophelia corals ( Cornelius 1995), polychaete tubes and ascidians ( Schuchert 2016). Gonothecae have been found in April ( Schuchert 2016) and November ( Gil & Ramil 2017).

In our material, colonies were growing on the hydroids Lafoea gracillima , Eudendrium ramosum (Linnaeus, 1758) and Halecium sp. , as well as on bivalves, a worm tube and a plastic net. One colony with gonothecae was found in November.

Distribution. This species has a North-Atlantic distribution, from the Lofoten Islands to Øresund and southwest Ireland in the East, and from northern Canada to Cape Cod in the West ( Calder 2012). Fraser’s (1944) record from the Pacific coast of North America was considered doubtful by Schuchert (2016). We also agree with him regarding the exclusion of the material from the Bay of Biscay reported by Vervoort (1985), due to its gonothecae being very different from the flattened ones described in C. producta by Schuchert (2016, as E. producta ) and those reported upon by Gil & Ramil (2017) from Mauritanian material. Its previously-known bathymetric distribution ranges from 6 to 750 m ( Schuchert 2016).

Our material was collected from Morocco to Guinea Bissau at depths of 504 to 1440 m.

Remarks. DNA barcoding of Cyclocanna welshi Bigelow, 1918 and Egmundella producta (Sars G.O. 1874) , prompted Schuchert et al. (2017) to conclude that the first nominal species is the medusa of the second. Because the distributions of the polyp and medusa, restricted to the cool waters of the North Atlantic, matched, the authors synonymised both names under the new combination, Cyclocanna producta (G.O. Sars, 1874) . Our records of typical colonies of ‘ E. producta ’ from deep waters of West Africa expand its southern limit of distribution from Southwest Ireland ( Calder 2012) to Guinea-Bissau.

The presence of gonothecae in the material collected from Mauritania and the morphology of the trophosome, with long hydrothecal pedicels and stolonal nematothecae, allowed us to identify this material as C. producta (see also Gil 2017).

MAURIT-0811

St. 10 (MU89) Pedicel, length from base to ‘diaphragm’ 1925–10000 diameter of pedicel 102–235 Hydrotheca, length ‘diaphragm’-rim, excluding. operculum 551–918

idem, including operculum 673–1102

diameter at rim 205–530

diameter at ‘diaphragm’ 143–230 Nematotheca, length including pedicel 56–72

maximal diameter 36–46 Gonotheca, length including pedicel 1150–2725 maximum width 938–2850

Figures

FIGURE 6. Cyclocanna producta (G.O. Sars, 1874), stn MU89; a, a portion of colony with hydrothecae; b, gonotheca seen frontally; c, nematothecae. Scale bar: a–b = 1 mm; c = 0.3 mm.