Sertularella vervoorti El Beshbeeshy, 2011

Horia R. Galea, Dirk Schories, Verena Häussermann & Günter Försterra, 2017, Taxonomic revision of the genus Sertularella (Cnidaria: Hydrozoa) from southern South America and the subantarctic, with descriptions of five new species, Revue suisse de Zoologie 124 (2), pp. 255-321 : 307-309

Sertularella vervoorti El Beshbeeshy, 2011

Fig. 18E ; Table 27

Sertularella vervoorti El Beshbeeshy, 2011: 151 , fig. 48. – Watson & Vervoort, 2001: 167, fig. 9. – Soto Àngel & Peña Cantero, 2015: 996, fig. 7J-K.

Sertularella cylindritheca . – Vervoort, 1972: 126, fig. 39A. – Stepanjants, 1979: 90, pl. 14 fig. 5A [non Sertularella cylindritheca ( Allman, 1888) = Sertularelloides cylindritheca ( Allman, 1888) ].

Material examined: ZMH C11552; FRV Walther Herwig, Stn. 327, Argentine Shelf, off Provincia de Santa Cruz, -51.18333° -56.95000°, 225 m; 29.06.1966; sterile, fragmentary colony (fragments 0.5-1.5 cm long) [material studied by El Beshbeeshy (2011)].

Description: Erect, though flaccid, up to 3.5 cm high colonies arising from creeping stolon. No definite main stem, the original stem branching several times subdichotomously; whole colony monosiphonic in habit. Both stems and branches divided into long, curved, slender internodes through distinct, oblique nodes; a hydrotheca, or a hydrotheca and one or two lateral, indistinct apophysis(es) immediately below its base; lower order branches arising not laterally, but almost perpendicular (in front or rear side) from their higher order counterparts. Hydrothecae strongly shifted to one side of the colony; very large, tubular, adnate to the corresponding internode for only a short part of their adaxial length, then curving outwards; abaxial wall almost straight for most of its length, slightly expanded below aperture; free adaxial wall gently curving basally, then straight; perisarc thin and smooth throughout; margin with 4 small, pointed cusps separated by shallow, semicircular embayments; renovations occasional; a 4-flapped operculum; hydranths with 18-20 filiform tentacles. Gonothecae arising from below the hydrothecal bases; elongated-ovoid, tapering basally, walls transversely-wrinkled; aperture distal, large, 4-cusped, and provided with a 4-flapped operculum.

Dimensions: See Table 27.

Remarks: The gonothecae of this species were described by Watson & Vervoort (2001), and subsequently found by Soto Àngel & Peña Cantero (2015).

Distribution: Argentina – Provincia de Buenos Aires [scattered records from offshore waters ( El Beshbeeshy, 2011)]; Provincia de Tierra del Fuego, Antártida e Islas del Atlántico Sur [off the NE coast of Isla de los Estados ( Vervoort, 1972, as S. cylindritheca )]. Falkland Is. – off the NE coast ( El Beshbeeshy, 2011). Scotia Arc – Burdwood Bank, South Georgia ( Soto Àngel & Peña Cantero, 2015). Tasmanian seamounts ( Watson & Vervoort, 2001).

Figures

Fig. 18. (A-D) Sertularella valdiviae Stechow, 1923 b (continued). Hydrothecae from ANT XIX / 5 ID. 91 (A), ZSM 20050522 (B) and ZSM 20050521 (C). Gonothecae from the latter source (D). (E) Sertularella vervoorti El Beshbeeshy, 2011, internode with hydrotheca. Scale bars: 200 μm (A-C, E), 500 μm (D).