Sertularella sanmatiasensis El Beshbeeshy 2011

Sertularella sanmatiasensis El Beshbeeshy, 2011

Fig. 16 E-G; Table 23

Sertularella sanmatiasensis El Beshbeeshy, 2011: 148, fig. 47. – Soto Àngel & Peña Cantero, 2015: 996, fig. 7H-I.

non Sertularella sanmatiasensis. – (?) Peña Cantero, 2006: 939, fig. 3L. – (?) Peña Cantero & Gili, 2006: 767. – (?) Peña Cantero, 2008: 459, fig. 2C. – (?) Peña Cantero & Vervoort, 2009: 87, fig. 2B. – Peña Cantero, 2012: 858, fig. 4A; 2013: 130 (possibly all = Sertularella antarctica Hartlaub, 1901).

Sertularella polyzonias. – Blanco, 1984: 37, pls 31-36; 1994: 200 [non Sertularella polyzonias (Linnaeus, 1758)].

Material examined: ZMH C11560; FRV Walther Herwig, Stn. 283, Argentine Shelf, -42.21667° -58.1000°, 500 m; 21.06.1966; numerous colony fragments up to 2.3 cm high, all sterile, with only the perisarc left (holotype).

Description: Colonies composed of upright, monosiphonic, unbranched or sparingly-branched stems, up to 5 cm high; a few basal annuli above origin from stolon; divided by oblique nodes into internodes of varied length, longer basally, gradually decreasing distally; a hydrotheca, or a hydrotheca and a short, lateral apophysis below its base, confined to the distal end of each internode. Branching pattern with a tendency to alternate; first internode with a number of spiral twists proximally, and comparatively longer than subsequent ones. Hydrothecae biseriate, alternate, coplanar to occasionally slightly shifted on to one side of the colony; large, flask-shaped, adnate for about 1/3rd their adaxial length; a characteristic notch at origin of free adaxial wall, then hydrotheca conspicuously swollen on same side, till below the aperture, where it is constricted; perisarc either smooth or with up to 3 undulations; abaxial wall straight to slightly concave; 4 marginal, blunt-ended triangular cusps of equal development separated by shallow, semicircular embayments; 3 intrathecal, submarginal cusps (2 latero-adaxial, 1 abaxial), variably present; rim not thickened, margin occasionally renovated up to 3 times. Gonothecae arising from below the hydrothecae; broadly ovoid, tapering below, walls undulated to nearly smooth; aperture distal, surrounded by 4 pointed cusps in male, less developed or absent in female; acrocysts in the latter.

Dimensions: See Table 23.

Remarks: The gonothecae of this species, absent in the material studied by El Beshbeeshy (2011), were documented earlier by Blanco (1984, as S. polyzonias). The intrathecal, submarginal cusps occur very inconstantly: sometimes only the abaxial one is present, sometimes only the pair of latero-adaxial, and occasionally the complete set of three occurs.

It was stated under S. antarctica that it is likely that some records assigned to S. sanmatiasensis in various papers (co)authored by Peña Cantero belong in fact to Hartlaub’s (1901) species. For instance, it is certain that the materials dealt with in Peña Cantero (2012, 2013) belong to the latter.

Distribution: Argentina – between Provincia de Río Negro and Provincia del Chubut [off Golfo San Matías (El Beshbeeshy, 2011)]. Scotia Arc – South Sandwich Is. (Soto Àngel & Peña Cantero, 2015). Antarctica – Isla Baja (Blanco, 1984, as S. polyzonias), Palmer Archipelago (Blanco, 1994, as S. polyzonias).