Muricea acervata Verrill, 1866

Breedy, Odalisca & Guzman, Hector M., 2015, A revision of the genus Muricea Lamouroux, 1821 (Anthozoa, Octocorallia) in the eastern Pacific. Part I: Eumuricea Verrill, 1869 revisited, ZooKeys 537, pp. 1-32 : 7

Taxon classification Animalia Alcyonacea Plexauridae

Muricea acervata Verrill, 1866 Figures 1, 2

Muricea acervata Verrill, 1866: 327-328; Rossi 1955; Harden 1979: 142.

Muricea (Eumuricea) acervata Verrill, 1869a: 419-421.

Eumuricea acervata Kükenthal, 1924: 143.

Material.

Holotype: YPM 1791 (figured specimen), dry, Bay of Panamá, Panamá, F.H. Bradley, 1866, no more data. Schizotype: USNM 1130758 (donated by YPM).

Description.

The holotype is a 20 cm tall and 12 cm wide colony, the branching is lateral, almost in one plane (Fig. 1A) candelabrum-like. All branches are thick and rigid with almost the same diameter, 7-8 mm, from base to top. Two main branches, subdivide from a 2 cm long stem in secondary branches that remain unbranched up to the top of the colony, or subdivide up to 3 times producing branchlets of almost the same diameter. The branches are up to 20 mm apart, branch at angles of 45°-90°, and curve upwards, with blunt tips. Undivided terminal ends are up to 7 mm in diameter and 70 mm long (Fig. 1 A–B). A vestige of the holdfast remains at the base of the stem. Axes are amber at the tips and darker at the base. Calyces are uniformly crowding the branches, close together, about 21 calyces/cm. They are up to 2.50 mm long and about the same in width, 1.8-2.0 mm. The rounded, small calyx apertures contain remains of anthocodial sclerites. The anthocodia are retracted and the eight projections of the calyces close over them. They are separated by slightly sunken grooves, which show an octoradiate star-like arrangement, that Verrill remarked as typical of this species ( Verrill 1869a) (Fig. 1B). However, it is the normal condition of polyps in this genus, when retracted. The coenenchyme is thick compared with the other three species. The outer coenenchyme is composed basically by the same type of sclerites found in the calyx. They are spindles of several shapes, mostly unilateral spinous, curved, straight, with blunt or acute ends, or one acute end and the other bifurcate. They are 0.50-1.82 mm long and 0.15-0.28 mm wide (Fig. 2A), Verrill (1869a) reported spindles up to 2 mm long. They are of a light brownish to dark orange colour, some with the outer surface darker than the inner (Fig. 1C). The axial sheath is composed of pale yellow to colourless (Fig. 1C), warty elongated spindles 0.15-0.30 mm long and 0.060-0.085 mm wide (Fig. 2B), and irregular radiates, up to 0.24 mm long and 0.10 mm wide (Fig. 2C). Anthocodial sclerites are pale yellow, irregular warty rods with a spinulose end 0.25-0.30 mm long and 0.037-0.060 mm wide, and small torch-like clubs with a warty handle, measuring up to 0.28 mm long and 0.10 mm wide (Fig. 2D). The colour of the colony is brown.

Distribution.

Reported only from the type locality, Bay of Panamá. This species has not been found in our recent surveys along the Pacific coast of Panamá. No data available about the depth range.

Remarks.

This species was first mentioned by Verrill (1866) as Muricea acervata in 1869. It was transferred to the genus Eumuricea and properly described from just one specimen from Panamá that represents the holotype. The species is different from the others by the thicker coenenchyme, and especially the shorter calyces with a wider apical aperture that exposes the contracted polyps, which in the other species are hidden in the tubes. The dark orange colour of the calycular and coenenchymal sclerites is not present in the other species, which are of various hues of brown instead.