Symplectoscyphus glacialis ( Jäderholm, 1904 )

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 : 127-128

Symplectoscyphus glacialis ( Jäderholm, 1904)

( Fig. 3E )

Symplectoscyphus glacialis — Briggs, 1938: 32–33; Peña Cantero, 2010: 37–38 (synonymy). Material examined. 48EV194, a mass of stems 80 mm in diameter, with gonothecae (IK–2012–10435) plus a stem fragment 30 mm long (IK–2012–10437).

Remarks. Symplectoscyphus exochus and S. glacialis are morphologically allied, both species having monosiphonic stems, irregular branching and similar hydrothecal shapes, but are easily recognizable by the shape of the gonothecae. The presence of two damaged gonothecae, and the size of the nematocysts (12 X 3.5), allow us to confirm the identification.

Ecology and distribution. Our material was collected at depths between 325 and 409 m, basibiont for colonies Abietinella operculata ( Jäderholm, 1903) , Bimeria corynopsis and Halecium interpolatum Ritchie, 1907 , and with gonothecae in December. Reported by Briggs (1938), at depths between 630 and 720 m, from Commonwealth Bay. Antarctic-Kerguelen distribution (Peña Cantero 2010).

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.