Cirrhipathes anguina ( Dana, 1846 )

Terrana, Lucas, Bo, Marzia, Opresko, Dennis M. & Eeckhaut, Igor, 2020, Shallow-water black corals (Cnidaria: Anthozoa: Hexacorallia: Antipatharia) from SW Madagascar, Zootaxa 4826 (1), pp. 1-62 : 25-27

Cirrhipathes anguina ( Dana, 1846)

Fig. 14

Antipathes anguina Dana 1846, p.576

Cirripathes anguina Brook 1889, p.84 -85

Cirripathes (Eucirripathes) anguina Van Pesch 1914, p.146 -153, figs.203-205, pl.8, figs.3-4, 7

Cirrhipathes anguinus: Bayer 1959, p.229

Material examined. Distal fragments of different colonies. Toliara 17–20 m specimens INV.131353, INV.131369, INV.131373, INV.131378, INV.131379, INV.131380; Anakao 10–11 m specimens INV.131362, INV.131363; Sarodrano 10 m specimens INV.131358, INV.131359, INV.131360; Maromena 20 m specimen INV.131355 .

Depth range. 7–30 m.

Description. The colonies are straight, slightly sinuous, and never form any loop or spiral in their distal parts ( Fig. 14 , a–g). Juvenile colonies have a thin stem, which can be bent within the first few cms ( Fig. 14 , h). Adult colonies can reach more than 5 m in length and can be bent at various points along the stem. The basal diameter reaches 1 cm in 3 m-high colonies. The colonies have a lot of different phenotypes with brown, white or grey coenenchymes and black, orange, white, or grey polyps ( Fig. 14 , a–h). The polyps are large and measure up to 2.9 mm in transverse diameter. Polyps are irregularly distributed around the stem, generally 3–6 polyps are found per cm (as seen in frontal view), with varying interpolypar spaces from 0.6 to 4.0 mm ( Fig. 14 , a–h), sometimes aggregating to one side of the colony, especially in juvenile colonies where two rows of polyps are found on one side ( Fig. 14 , h).

All these phenotypes present the same spine morphology in their distal parts ( Fig. 14 , j). The spines are highly papillose, mainly stout with a rounded apex ( Fig. 14 , k), but conical spines can also be found ( Fig. 14 , o). Adjacent spines can be fused at their base. Irregular growths are sometimes seen on stout spines ( Fig. 14 , l, m). Newly formed spines are found either with a narrower cylindrical shape, or minute triangular shape ( Fig. 14 , n, o), but due to their scattered presence they are not ascribable to true secondary spines. All fully formed spines, independent from the occurrence of irregularities, show a distinctly papillose surface ( Fig. 14 , k–o). The spines of the two different sides of the spines as seen in frontal view measure up to 0.30 mm in height and their mutual distance measures up to 0.70 mm. They either stand at right angles to the corallum or are slightly inclined in different directions ( Fig. 14 , j). Up to 26 irregular rows can be seen in one aspect on a distal portion 3.5 mm in diameter. On a distal fragment 0.48 mm in diameter from a 30 cm-high young colony, there is a single type of spine. They are triangular and laterally compressed but show a distinct papillose surface ( Fig. 14 , i, o). They measure 0.11–0.19 mm in height and their mutual distance is 0.20–0.48 mm. The spines are clearly arranged in seven rows, as seen from one aspect.

Taxonomic remarks. The type specimen of this species is lost. In its brief description, Dana (1846) states that this species has polyps “not properly beaked” and measure about 4 mm in diameter. The spines are stout and hardly acute and there are “distinct nodes in the axis every three or four inches towards the upper extremity”. Pending the description of a neotype, the descriptions of Ci. anguina sensu Brook 1889 and van Pesch 1910 are used here. Van Pesch (1914) describes blunt and conical spines at right angles to the corallum as well as spines more acute and distally inclined with a rough surface. The spine sizes reported by van Pesch are within the range of those observed for the Malagasy specimens. The spines described by Brook (1889) and van Pesch (1914) differ from the Malagasy specimens in having a different number of rows, which is 12-14 for both authors. However, this number generally tends to vary according to which portion of the colony is analyzed. The mutual distance of the spines of the Malagasy specimens, 0.45 mm, is also similar ( van Pesch 1914). Brook (1889) affirms that the stem of Ci. anguina is never twisted into regular spirals and the spines are of the same size around the corallum. Indeed, the difference in spines is not as marked as in other species and genera. More simple spines as seen here in the fragment of the young colony depend both on the position on the axis (growing apex with newly forming spines) and the age of the colony. With respect to the polyps, both Brook (1889) and van Pesch (1914) describe polyps arranged all around the colony with varying interpolypar spaces and sizes reaching 4 mm in diameter, which is consistent with the polyps of the Malagasy specimens. Slight differences are perhaps related to intraspecific variation or environmental effects on the shape and size of the colony. The present description is similar to the one given by Wagner (2015a) for Hawaiian specimens identified as Ci. anguina .

Distribution. Fiji islands (type locality, Dana 1846), Maldives ( Cooper 1903), Red Sea ( Cooper 1903), Seychelles ( Cooper 1903), Sri Lanka ( Cooper 1903), New Guinea ( van Pesch 1914), Cape Moreseby ( van Pesch 1914), Japan ( Okiyama & Tsukamoto 1989), Indonesia (Rumphius, see Bayer 1959), Andaman & Nicobar Islands ( Kumar et al. 2012), Hawaii ( Grigg 2001), Madagascar (present study).

Figures

FIGURE 14. Cirrhipathes anguina (Dana, 1846) (a–h) In situ pictures showing the wide range of phenotypes that the species can present (a—INV.131378; b—INV.131369; c—INV.131373; d—INV.131379; e—INV.131360; f—INV.131359; g— INV.131362; h—INV.131363). All these phenotypes have the same spine morphology. (i) Distal section 0.48 mm in diameter from the 30 cm-long juvenile colony INV.131363. At this stage, regular rows of spines can be seen. (j) Distal section 3.5 mm in diameter of a 2.5 m tall colony INV.131379. The regular rows formed by the spines start to be lost. (k–n) Different spine morphologies seen on distal parts of Ci. anguina colonies. The spines are generally stout and papillose but irregular growths are sometimes found, as well as triangular, minute spines or cylindrical, narrow newly formed spines. (o) Triangular, laterally compressed spines from a distal fragment of the juvenile colony INV.131363.