Oswaldella erratum Peña Cantero & Vervoort, 1997

Peña Cantero, Álvaro L. & Marzal, Marina Fresneda, 2018, Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica), Zootaxa 4441 (1), pp. 121-136 : 133

Oswaldella erratum Peña Cantero & Vervoort, 1997

( Fig. 3I )

Oswaldella erratum — González Molinero & Peña Cantero, 2015: 435 (synonymy).

Material examined. 38EV73, four stem fragments up to 80 mm high, with gonothecae (IK–2009–0498).

Description. Monosiphonic, unbranched stems, up to 80 mm high, not divided into internodes. Angle between cauline apophyses and stem c. 70°. Cauline apophyses with two aXillary nematophores. First hydrocladial internode bifurcated with two similar prongs. Hydrotheca elongate ( Fig. 3I ), not completely adnate, placed on middle of internode. Adcauline wall strongly curving at distal part. Hydrothecal aperture kidney-shaped, adcaudally directed. Mesial-inferior nematophore provided with a nematotheca.

Ecology and distribution. Present material collected at depths between 689 and 720 m, with gonothecae in December. Oswaldella erratum was considered to have a West Antarctic distribution (Peña Cantero & Vervoort 2004b; González Molinero & Peña Cantero 2015), however, our material, from East Antarctica, indicates a circum- Antarctic distribution.

Figures

FIGURE 3. Staurotheca antarctica Hartlaub, 1904: A, hydrothecae. Staurotheca nonscripta Peña Cantero, Svoboda & Vervoort, 1997: B, hydrotheca. Staurotheca pachyclada (Jäderholm, 1904): C, hydrotheca. Antarctoscyphus spiralis (Hickson & Gravely, 1907): D, internode with hydrotheca showing intrathecal cusps (arrow). Symplectoscyphus glacialis (Jäderholm, 1904): E, internode with hydrotheca. Halecium interpolatum Ritchie, 1907: F, incipient stem with distal hydrotheca (arrow pointing to characteristic long and straight basal part of internode). Abietinella operculata (Jäderholm, 1903): G, hydrotheca (arrow pointing to disc-shaped operculum) and nematotheca (arrow). Schizotricha nana Peña Cantero, Svoboda & Vervoort, 1996: H, unforked hydrocladial internodes showing hydrothecae and nematothecae. Oswaldella erratum Peña Cantero & Vervoort, 1997: I, hydrocladial internode showing hydrotheca and mesial inferior nematotheca (arrow). Scale bars: 200 µm.