Symplectoscyphus exochus Blanco, 1982

Soto, Joan J. & Peña, Álvaro L., 2019, Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica), Zootaxa 4570 (1), pp. 1-78 : 35-36

Symplectoscyphus exochus Blanco, 1982

( Fig. 11d , 12d )

Material examined. ANT XV/3: 48-4, few stems, c. 9 mm high; 48-44, mass of stems, c. 40 mm high, with gonothecae and few stems, up to 14 mm high, on bryozoan; 48-58, mass of stems, c. 40 mm high, with developing gonothecae; 48-72, some stems, up to 10 mm high; 48-168, some stems, up to 25 mm high, on Sy. liouvillei ; 48- 189, some stems, up to 15 mm high; 48-220, mass of stems, c. 40 mm high, with gonothecae, and few stems, up to 30 mm high, on Sc. nana and Sy. anae ; ANT XVII/3: 111-6, mass of stems, c. 30 mm high; 111-9, some stems, up to 20 mm high, on T. longstaffi , with developing gonothecae; ANT XXI/2: PS65/39, mass of stems, c. 65 mm high, with gonothecae, and some stems, up to 15 mm high, on Sc. nana , with gonothecae; PS65/121, several stems, up to 35 mm high, on St. dichotoma ; PS65/132, several stems, up to 20 mm high, on B. subrufa ; PS65/166, mass of stems, c. 40 mm high, with developing gonothecae; PS65/174, several stems, up to 30 mm high, on B. subrufa , with gonothecae; PS65/237, some stems, up to 25 mm high, on Sc. nana and S. lobata , and mass of stems, c. 40 mm high, with gonothecae; PS65/248, few stems, up to 6 mm high; PS65/253, mass of stems, up to 60 mm high, with gonothecae; PS65/265, mass of stems, up to 30 mm high, and some stems, up to 12 mm high, on B. subrufa ; PS65/276, mass of stems, up to 40 mm high, with developing gonothecae; PS65/278, few stems, up to 12 mm high; PS65/279, mass of stems, c. 30 mm high, with developing gonothecae.

Remarks. Material devoid of reproductive structures is tentatively assigned to Sy. exochus . According to Peña Cantero (2017), the separation between Sy. exochus and Sy. glacialis in the absence of gonothecae is rather difficult because both species may develop very similar hydrothecae.

Ecology and distribution. Species reported at depths between 15 ( Vervoort 1972b, as Symplectoscyphus glacialis ) and 1958 m ( Peña Cantero 2012); present material collected from 62 to 352 m. Species with circum- Antarctic distribution ( Peña Cantero 2014a).

Figures

FIGURE 11. a Symplectoscyphus anae: hydrotheca. b Sy. cumberlandicus: hydrotheca. c Sy. curvatus: hydrotheca. d Sy. exochus: hydrotheca. e Sy. frigidus: hydrotheca. f Sy. glacialis: hydrotheca. g Sy. liouvillei: hydrotheca. h Sy. naumovi: hydrotheca. i Sy. paulensis: hydrotheca. j Sy. plectilis: hydrotheca. k Sy. vanhoeffeni: hydrotheca. l Sy. weddelli: hydrotheca.

FIGURE 12. a Symplectoscyphus anae: gonotheca. b Sy. cumberlandicus: gonotheca. c Sy. curvatus: gonotheca. d Sy. exochus: gonotheca. e Sy. glacialis: gonotheca. f–g Sy. liouvillei: f colony; g gonotheca. h Sy. naumovi: gonotheca. i Sy. plectilis: gonotheca. j Sy. vanhoeffeni: gonotheca. k Sy. weddelli: gonotheca.