Thouarella koellikeri Wright & Studer, 1889

Pérez, Carlos Daniel & Zamponi, Mauricio Oscar, 2004, New records of octocorals (Cnidaria, Anthozoa) from the south western Atlantic Ocean, with zoogeographic considerations, Zootaxa 630, pp. 1-12 : 7

Thouarella koellikeri Wright & Studer, 1889

( Fig. 3A )

Thouarella koellikeri Wright & Studer, 1889: 64 –65; May 1899: 14; Versluys 1906: 35. Thouarella (Parathouarella) koellikeri Kükenthal, 1915: 150 ; 1919: 435; 1924: 299.

Diagnosis. See Wright & Studer, 1889: 64–65, pl. 21, fig. 5.

Material examined. ARGENTINA, Buenos Aires, Mar del Plata, 39°00'S, 57°10'W, March 1925, 147– 318 m, Vessel “Undine”, collector Dr. A. Capello, ( MACN 15257).

Description. Branched colony, 12.8 cm in height. Branches coming off the main stem in three directions but attaining a biserial or slightly secund arrangement rather than a bottlebrush form as they bend in one direction, defining a front and a rear side of the stem. Front branches simple and short (0.5–1.5 cm), near branches occasionally ramified and long (2–8 cm), and angled at 60º relative to the stem. Terminal branches sometimes slightly curved. Polyps pear­shaped, 1.8–2 mm long, arising singly in three directions, surrounding the branches in short spirals. Sclerites are scale­shaped with margins finely toothed. Polyp scales placed in five abaxial and two adaxial longitudinal rows and in seven to eight transverse rows. Abaxial scales with serrated margins and short spines (0.48 mm wide and 0.37 mm long) and adaxial scales small, with radial ridges and covered by the broad lateral ones (0.27 mm wide and 0.29 mm long). Opercular scales triangular, bearing foliate processes with radial ridges and a median rib projecting into a pronounced spine (0.32 mm wide and 0.62 mm long). Marginal scales bearing foliate processes with the median rib developed into a short spine (0.49 mm wide and 0.44 mm long). Coenenchymal scales irregularly triangular, round, polygonal or quadrangular, overlapping one another (0.17 mm wide and 0.30 mm long).

Distribution ( Fig. 1 ). Tom Bay (50º10’S, 74º42’W, 53 m) ( Chile), Sarmiento Channel ( Chile), depth 122 m ( Wright & Studer 1889).

New record: Mar del Plata coast, south of Buenos Aires Province ( Argentina).

Remarks. This record is the first for the Atlantic Ocean and it extends the distribution of this species up to the south east American coast.

Figures

FIGURE 1. Geographical distribution of the studied species of octocorals in the Subantarctic Region. Alcyonium paessleri; Alcyonium haddoni; ˖ Primnoella biserialis; Primnoella compressa; ★ Dasystenella acanthina; Thouarella koellikeri.

FIGURE 3. A. Thouarella koellikeri Wright & Studer, 1889, dry sample, MACN 15257. B. Primnoella biserialis Wright & Studer, 1889, dry sample, MACN 22872. C. Primnoella compressa Kükenthal, 1980, dry sample, MACN 16608.