Tanacetipathes tanacetum ( Pourtalès, 1880 )

Lima, Manuela M., Cordeiro, Ralf T. S. & Perez, Carlos D., 2019, Black Corals (Anthozoa: Antipatharia) from the Southwestern Atlantic, Zootaxa 4692 (1), pp. 1-67 : 26-27

Tanacetipathes tanacetum ( Pourtalès, 1880)

Figs. 13 , 14

Antipathes tanacetum Pourtalès, 1880: 116 , pl. 3, fig. 13; Brook, 1889: 162; Opresko, 1972: 984–986, tab. 2, fig. 7; Echeverría & Castro, 1995: 1–7, figs. 2–5 (part);

Tanacetipathes tanacetum: Opresko, 2001 a: 358 –361, figs 11a, 12d; Opresko, 2001 b: 349, figs. 7–10; Pérez et al., 2005: 3–8, figs 1–4; Loiola & Castro, 2005: 12–19, figs 7–10; Opresko & Sanchez, 2005: 502, fig 12; Loiola, 2007: 256–257.

Type and type locality. MCZ 57361 (lectotype): Saint Vincent and the Grenadines, 13º12’9.972”N 61º17’17.988”W, 173 m.

Material examined. Brazil, off Rio Grande do Norte, Potiguar basin, 4º43’59.988”S, 36º25’59.999”W; depth 101–108 m. Programa de Caracterização da Bacia Potiguar, PETROBRAS, Date : 05/2011 ( MOUFPE–CNI 351 , 48 specimens) .

Diagnosis. Corallum monopodial or rarely with branches up to the 2nd order, arising near to the colony base, pinnulated; the primary pinnules are arranged biserially mainly in four rows; however in places a few pinnules corresponding to a 5th and 6th row also occur. The posterior primary pinnules are the longest and the anterior primaries (corresponding to the 5th and 6th rows) are the shortest. The posterior primary pinnules are up to 1.2 cm long in holotype, and about 0.25 mm in diameter near the base (excluding spines). Maximum length of anterior primary pinnules 3–19 mm. There are one to three secondary pinnules on the posterior primary pinnules, usually arranged uniserially on the abpolypar side of the axis. The secondaries closest to the base of the posterior primaries are up to 6 mm long. The small anterior pinnules lack subpinnules. Tertiary pinnules, mostly one or two, but sometimes three, are present on many of the secondaries, usually on the abpolypar side, about 3 mm in length or less. The polypar spines on the primary pinnules are 0.08–0.12 mm tall, as measured from the middle of the base to the apex. The abpolypar spines are 0.07–0.09 mm. Some of the spines possess small, flattened, oval to elongated papillae on the middle of their surface. The polyps are 0.6 to 0.8 mm in transverse diameter; 10–13 per centimeter (adapted from Perez et al., 2005).

Description of Brazilian specimens. Corallum monopodial, rarely with branches up to the 2nd order, in bottlebrush form, whose primary pinnules are usually arranged in 4 rows ( Fig. 13a ). Posterior primary pinnules longer than the anterior primaries, with length between 6 and 20 mm, varying according to size of the studied colony. Anterior primary pinnules usually with a length between 5 and 7 mm. Distance between one cycle of primary pinnules and another of approximately 1 mm. Angle between posterior primary pinnule and anterior primary pinnule (polypar and abpolypar sides, respectively) of about 45°. Angle between two anterior primary pinnules or two posterior primary pinnules (polypar/polypar sides or abpolypar/abpolypar, respectively) of approximately 160°. A few secondary pinnules usually located near the proximal end of posterior primary pinnules. Number of secondary pinnules per posterior primary between 3 and 7, but more commonly between 4 and 5 ( Fig. 13 b–c). Tertiary pinnnules rarely present, usually 1 or 2 per secondary pinnule when present. Spines conical and with a few papillae. Polypar spines varying between 0.048 mm and 0.11 mm in height ( Fig. 13d ), and 0.12–0.18 mm apart within each row. Size of abpolypar spines between 0.036 mm and 0.06 mm. Polyps not present (lost tissue).

Remarks. The lectotype of T. tanacetum was designated by Pérez et al. (2005). The material studied here shows posterior primary pinnules slightly longer than those described for the type (up to 2 cm in the Potiguar Basin material, compared to 1.2 cm in the lectotype). The specimens of Tanacetipathes tanacetum described herein have spines slightly smaller than those reported in the literature [0.07–0.12 mm in lectotype ( Pérez et al., 2005); 0.13–0.3 mm in Opresko & Sanchez (2005); 0.04–0.27 mm in Loiola & Castro (2005) for Brazilian specimens; 0.048–0.11 mm in the present work]. The secondary pinnules of the Potiguar Basin specimens are larger than those described for the lectotype [up to 13 mm in the present work; 6 mm in the lectotype ( Pérez et al., 2005)], but are within the size range quoted in Loiola & Castro, 2005 for specimens of T. tanacetum on the coast of the state of Bahia, Brazil (up to 22 mm in length). Furthermore, the size of the spines is similar to that found in the lectotype [0.07–0.12 mm ( Pérez et al., 2005)], and the shape and density of the spines and the pinnulation pattern justify identifying our specimens as this taxon. The typical morphotype of T. tanacetum also differs from specimens from the Potiguar Basin, as the first usually have uniserial secondary pinnules, shorter anterior primary pinnules and shorter proximal secondary pinnules in comparison to the later. However, information on variability boundaries within this species is still wanting.

This is the first record of the species for the Potiguar RN Basin. Pourtalès (1880), in the original description of the species, emphasizes the presence of a “parasitic worm”, similar to that which produces the tube in Stylopathes columnaris . The association between T. tanacetum and polychaetes of the species Parahololepidella greeffi is also recorded here. Pettibone (1991) points out the symbiosis between Tanacetipathes tanacetum and polychaetes of the species Antipathipolyeunoa nuttingi Pettibone, 1991 , presenting an identification key for this group of Annelida based mainly on the black coral species to which it is associated.

Distribution. Atlantic Ocean: off Bermuda (Cairns et al., 1986), Gulf of México ( Opresko, 2009) and Southwestern Atlantic, Brazil, Parcel Manuel Luís ( Opresko, 1972), Atol das Rocas ( Opresko, 1972), Bacia Potiguar (this work), off Bahia, Espírito Santo and Rio de Janeiro ( Loiola & Castro, 2005), and Cadeia Vitória—Trindade ( Loiola & Castro, 2005) ( Fig. 14 ); from 26 m (Smithsonian, USNM 53472, identified by D. M. Opresko; available in <http://collections.nmnh.si.edu/search/iz/>) to 1362 m depths ( Castro et al., 2006).

Figures

FIGURE 13. MOUFPE-CNI 351: Tanacetipathes tanaceum (Pourtalès, 1880). a—Corallum morphology; b—Cross section showing one cycle of pinnules (specimen 1); c—Cross section showing one cycle of pinnules (specimen 2); d—Organization of spines.

FIGURE 14. Geographic distribution of Tanacetipathes tanacetum (Pourtalès, 1880). Yellow circles: records extracted from the literature (Opresko, 1972; Cairns et al., 1986; Loiola & Castro, 2005; Opresko, 2009) and based on Ocean Biogeographic Information System (OBIS). Red circle: record made in the present work.