Modeeria rotunda ( Quoy & Gaimard, 1827 )

Peña Cantero, Álvaro L. & Horton, Tammy, 2017, Benthic hydroids (Cnidaria, Hydrozoa) from bathyal and abyssal depths of the Northeast Atlantic held in the modern Discovery Collections, Zootaxa 4347 (1), pp. 1-30 : 10

Modeeria rotunda ( Quoy & Gaimard, 1827)

( Fig. 4A–B )

Modeeria rotunda — Vervoort & Watson, 2003: 31 –32 (synonymy).

Material examined. 51217#1, several hydrothecae, on Sertularella gayi , no gonothecae.

Description. Stolonal colonies, a filiform hydrorhiza giving rise to small hydrothecae on short pedicels ( Fig. 4A ). Hydrotheca tubiform, with basal circular diaphragm ( Fig. 4B ). Hydrothecal rim uneven, with two large cusps, separated by two large embayments ( Fig. 4A ). Operculum composed of two semi-circular, pleated valves, attached to rim embayments and closing as a roof.

Measurements (in µm). Hydrotheca: diameter at aperture 220–230; height, up to diaphragm 730–800, diameter at diaphragm 80–100, length of pedicel 100.

Ecology and distribution. Eurybathic species, found at depths from 0.5 ( García Carrascosa 1981) to 1214 m (Schuchert 2001); the present material was collected from the Porcupine Seabight at 150 m, on Sertularella gayi .

Circumglobal from boreal to tropical waters ( Vervoort & Watson 2003).

Figures

FIGURE 4. Modeeria rotunda (Quoy & Gaimard, 1827): A, hydrotheca; B, basal part of hydrotheca showing diaphragm (arrow). Stegolaria geniculata (Allman, 1888): C, hydrotheca (note geniculate arrangement); D, hydrotheca showing plicate operculum; E, basal part of hydrotheca showing diaphragm (arrow); F, detail of distal part of hydrotheca. Stegopoma plicatile (M. Sars, 1863): G, adnate hydrotheca; H, free hydrotheca. Scale bars: Scale bars: 200 µm (A, C-D, G-H), 100 µm (B, E – F),