Primnoella compressa Kükenthal, 1908

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 : 8-9

Primnoella compressa Kükenthal, 1908

( Fig. 3 C)

Diagnosis. See Tixier­Durivault 1969 –70: 162.

Material examined. URUGUAY: Estuary of Río de la Plata, 35°30'S, 52°50'W, May 1926, 196– 230 m, Vessel “Undine”, collector Cap. C. Alexanderson, ( MACN 16608); 35°35'S, 52°45'W, September 1935, 230– 263 m, Vessel "Maneco", ( MACN 22870); 35°03'S, 52°45'W, September 1935, 230– 263 m, Vessel "Maneco", ( MACN 32946). ARGENTINA: Tierra del Fuego, 54°23'S, 65°42'W, 1941, 164 m, "Bahía Blanca” A.R.A., collector Commandant of Ship, R. Mata, ( MACN 24882).

Description. Unbranched, whip­like colonies ranging between 60 cm and 80 cm in height. Polyps arranged in whorls of 14–16 congested along the entire stem at 4–5 whorls per centimetre. Polyps 1.2–1.5 cm in height, with two longitudinal abaxial rows of scales with 23–26 scales per row, meeting at a zigzag abaxial suture. The adaxial side of the polyps is shorter than the abaxial and not fused with the stem. Scales with big multituberculate warts. Abaxial scales big, uniform and rectangular (0.37 mm wide and 0.16 mm long), adaxial scales small and diamond­shaped (0.14 mm wide and 0.20 mm long). Coenenchymal scales ovoid (0.17 mm wide and 0.19 mm long), triangular (0.27 mm wide and 0.18 mm long) and triangular with a large projecting wart (0.13 mm wart long).

Distribution ( Fig. 1 ). Iquique ( Chile) ( Kükenthal 1919); Mar del Plata (37º36’S, 54º46’W, 740 m) ( Argentina) ( Tixier­Durivault 1969–70).

New records: Estuary of Río de la Plata ( Uruguay) and Tierra del Fuego ( Argentina). Remarks. The record off the Tierra del Fuego coast is the southern most for the Atlantic Ocean.

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.