Tanacetipathes longipinnula new species

Figure 14

Antipathes tanacetum: Echeverría & Castro, 1995: 1 –7, Figs. 2–5 (part) [non Tanacetipathes tanacetum (Pourtalès, 1880)].

Material examined. Brazil: off Vitória, 20 ° 29’ S, 0 36 ° 05´W, 50 m, REVIZEE Central V Sta. #23 (MNRJ 5595: 1 colony—holotype; MNRJ 4667: 1 colony—paratype;); Almirante Saldanha Bank, 22 ° 22’ S, 0 37 ° 35’ W, 240 m, REVIZEE Central VI (MNRJ 5146: 1 colony—paratype); off Cape of São Tomé, 22 ° 26’ S, 0 40 ° 35’ W, 106 m (MNRJ 2367: 1 colony—paratype); off Cabo Frio, 23º01’S, 040º57’ W, 110m (MNRJ 5147: 1 colony—paratype).

Diagnosis. Corallum monopodial, with long posterior primary pinnules (maximum length 23–40 mm), long secondary pinnules (maximum length 47 mm), long tertiary pinnules (maximum length 28 mm), and short spines (0.15 mm or less) with small ornamentations; polyps not known.

Holotype. Colony monopodial, 37 cm high, 5.5 cm wide (Fig. 14 a–b). Colony emerges from a basal plate with 32 mm in diameter (Fig. 14 a–b). Diameter of axis near the base 3.5 mm. Primary pinnules in 4 or 5 rows, in laterally alternating groups; length of anterior primaries 10–33 mm, length of posterior primaries 24–40 mm; diameter of the primaries 0.20–0.36 mm, second anteriors tending to be slenderer than the others (Fig. 14 c); distance between adjacent (in the same row) primaries 2.1–2.7 mm. Five to six primary pinnule cycles per centimeter of axis (Fig. 14 b). Secondary pinnules only on the proximal half of primaries, on the abpolypar side, up to 4 per primary pinnule; up to 28 mm long, 0.16–0.36 mm in diameter; very elongated and curved towards the distal portion of the primaries (Fig. 14 c). Tertiary pinnules common, 1–2 per secondary, maximum length 19 mm, on the abpolypar side of the secondaries (Fig. 14 c). Spines conical, slightly compressed, with small papillae over the whole surface, distal portion inclined and, occasionally, slightly curved towards the distal end of the pinnules; 8–9 irregular longitudinal rows (around the whole pinnule); polypar spines 0.09–0.13 mm tall, 0.04– 0.06 mm wide at base; abpolypar spines 0.04–0.06 mm tall, 0.01–0.03 mm wide at base; 4–6 spines per millimeter in a row; distance between adjacent spines in each row 0.11– 0.26 mm (Fig. 14 d–h). Polyps badly damaged.

Variations Found in the Paratypes. Monopodial colonies 11.0–52.0 cm tall, 4.7–8.0 cm wide. Axis 0.9–3.7 mm in diameter near the base, and basal plate, when present, 19.0– 25.0 mm in diameter. Primary pinnules in 4 to 6 rows; maximum length of anterior primaries 13–16 mm (species average including holotype 17.80 ± 9.14 mm), maximum length of posterior primaries 24–35 mm (species average including holotype 29.20 ± 6.05 mm); distance between adjacent (in the same row) primaries 0.9–2.3 mm. Secondary pinnules maximum length 47 mm (species average including holotype 29.90 ± 10.62 mm), 0.12–0.36 mm in diameter. Tertiary pinnules maximum length 26 mm (species average including holotype 13.20 ± 6.25 mm). Quaternary pinnules rarely present. Spines in 6–10 irregular longitudinal rows (around the whole pinnule); polypar spines 0.07–0.15 mm tall, 0.03–0.06 mm wide at base; abpolypar spines 0.03–0.08 mm tall, 0.01–0.05 mm wide at base; distance between adjacent spines in each row 0.11–0.28 mm. Polyps also badly damaged.

Etymology. The name longipinnula is used as a compound noun in apposition with the generic name (International Commission on Zoological Nomenclature, 1999: article 31.2.1), derived from “ longus” (Latin, elongate) and “ pinnula” (Latin, feather, pinnule), in reference to the comparatively great size of pinnules and subpinnules.

Remarks. Tanacetipathes longipinnula has much longer secondary (up to 47.0 mm) and tertiary pinnules (up to 26.0 mm) than any other species of this genus. The maximum length of the primary pinnules of T. longipinnula (40.0 mm) is similar to that observed in T. barbadensis (45.0 mm, Brook, 1889, Warner, 1981). However, T. barbadensis is different from T. longipinnula because of its branched colonies (although sparsely so), larger number of secondaries per primary pinnule (usually up to 8, rarely up to 20, occasionally only 1 or 2 secondaries set very close to the primary origin), tertiary pinnules short and rarely present, and taller polypar spines— 0.10–0.30 mm (Brook, 1889; Warner, 1981; diagnosis herein included).

The number and arrangement of the secondary and tertiary pinnules are similar in T. hirta and in T. longipinnula, n. sp.: 4 to 6 secondaries, on the proximal half of the primaries, on the abpolypar side; 1 to 3 tertiary pinnules per proximal secondary pinnule (Opresko, 1972; Warner, 1981). These two species also have in common the range in height of their spines: T. hirta polypar spines 0.07–0.17 mm, abpolypar spines 0.03–0.13 mm (Opresko, 1972; Warner, 1981). However, T. hirta is branched and fan shaped, and has shorter secondary (3–10 mm long, average 5 mm, Opresko, 1972; 15 mm long, Warner, 1981: Fig. 7) and tertiary pinnules (see Opresko, 1972: Fig. 6 D, Warner, 1981: Fig. 7).

Tanacetipathes tanacetum is close to the new species, but the distribution of secondary pinnules (scattered over a larger area along the primary in T. tanacetum) and the more frequently elongated condition of pinnules of the new species give each of these species a distinctive appearance. Although occasionally a pinnule of T. tanacetum may be as long as the pinnules in specimens of the new species with relatively short pinnules, the length of a set of pinnules of each species is clearly different. Echeverría & Castro (1995) studied some specimens from Bacia de Campos, RJ, identifying them as T. tanacetum . However, two of these specimens (MNRJ 2367 and one specimen of MNRJ 2368—removed to MNRJ 5147) belong to T. longipinnula .

Tanacetipathes cavernicola, T. spinescens, T. thamnea, and T. wirtzi are branched colonies, and have primary, secondary, and tertiary pinnules that are smaller in length than those in Tanacetipathes longipinnula . There are also differences in the position and number of subpinnules. Besides, the heights of polypar and abpolypar spines are different between the species cited above (except T. spinescens) and T. longipinnula (see Brook, 1889; Warner, 1981; Opresko, 2001b; descriptions of T. cavernicola and T. thamnea here included). Also, Tanacetipathes wirtzi has no tertiary pinnules (Opresko, 2001b). The colonies of T. spinescens are densely branched and the primary pinnules are shorter, up to 15 mm long.

Distribution. Atlantic: Brazil, off Rio de Janeiro and off Espírito Santo (20º–23º S—Fig. 1), in depths between 50 and 240 m.