Egmundella superba Stechow, 1921

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 : 496-498

Egmundella superba Stechow, 1921

( Fig. 4b ; Table 3)

Egmundella superba Stechow, 1921: 226–227 ; Stechow, 1923: 126–127, fig. R; Vervoort, 1966: 110, fig. 10; Calder, 1991: 11–12, fig. 4.

Campanulina producta — Leloup, 1940: 8, pl. I fig. 4.

Material examined. Morocco. MAROC-0411, stn MO49, 34º12′14″– 34º11′32″N, 7º21′01″– 7º23′02″W, 1013– 1024 m, 29-XI-2004: three colonies, 0.8– 3 mm high, one growing on Acryptolaria conferta minor , two growing on sponges, all without gonothecae .

MAROC-0611, station data lost: two colonies, 2.4–3.5 mm high, one growing on Lafoea gracillima , and one on fishing line, both without gonothecae.

Mauritania. MAURIT-1011, stn MU290 , 18 º16′53″– 18º18′44″N, 18º18′44″– 16º35′35″W, 311 m, 14-XII-2010: a colony growing on the bivalve Delectopecten vitreus , without gonothecae .

Description. Colonies stolonal, with hydrothecae and nematothecae arising from filiform hydrorhiza. Hydrothecae borne on long, slender, smooth pedicels widening distally, with 2–3 basal undulations and some irregularly-placed, additional annulations. Hydrotheca long, tubular, narrowing basally at junction with its corresponding pedicel, and there delimited by a transverse, thin diaphragm; rim not apparent, aperture closed by an operculum composed of more than fifteen elongate, triangular flaps. Nematothecae long, slender, widening distally, borne on indistinct pedicels, aperture apical, circular.

Biology. This species was found growing on the axis of an octocoral by Calder (1991).

In our material, the colonies were growing on the hydroids Acryptolaria conferta minor ( Ramil & Vervoort, 1992) and Lafoea gracillima ( Alder, 1856) , on sponges, on the bivalve Delectopecten vitreus (Gmelin, 1791) , and on a fishing line. Gonothecae were not observed.

Distribution. Egmundella superba is basically an amphi-Atlantic species, with records from Saint Thomas, West Indies (type locality) ( Stechow 1921), the Bermuda ( Calder 1991) and the Azores ( Leloup 1940, as Campanulina producta ); in addition, there is a doubtful record from off Natal, SW Indian Ocean ( Millard 1977, as Egmundella ? superba ). Its bathymetric distribution ranges from 75 ( Calder 1991) to 1250 m ( Leloup 1940).

Our material was collected from Morocco and Mauritania, from depths of 311 to 1024 m.

Remarks. Our material agrees in both morphology and measurements with specimens of E. superba from the West Atlantic ( Calder 1991). Moreover, the distinctive shape and length of the nematothecae, and the long and slender hydrothecae ( Fig. 4b ), are features that allowed us to identify this material as E. superba .

Figures

FIGURE 4. a, Egmundella modesta Millard & Bouillon, 1975, stn MO235, hydrorhiza with hydrothecae and nematothecae. b, Egmundella superba Stechow, 1921, stn MO49, hydrorhiza with hydrothecae and nematothecae. Scale bar: a–b = 1 mm.