Muricea formosa Verrill, 1869

Breedy, Odalisca & Guzman, Hector M., 2016, A revision of the genus Muricea Lamouroux, 1821 (Anthozoa, Octocorallia) in the eastern Pacific. Part II, ZooKeys 581, pp. 1-69 : 12-15

Taxon classification Animalia Alcyonacea Plexauridae

Muricea formosa Verrill, 1869 Figures 5, 6, 7

Muricea formosa Verrill, 1869: 434-436; Kükenthal 1919: 752; Kükenthal 1924: 143; Harden 1979: 146.

Material.

Holotype. YPM 1621a, ethanol preserved, Zorritos, Tumbes Department, Perú, 5 m, F.H. Bradley, 1866-1867. Schyzotypes. PERÚ: MCZ 35945, 3 dry fragments, YPM 1621b, ethanol preserved fragment, Zorritos, 5 m, F.H. Bradley, 1866-1867.

Description.

The holotype is a 10 cm long and 6 cm wide colony, branching lateral, in one plane and irregularly dichotomous (Fig. 5A). It arises from a conical holdfast about 100 mm tall and about the same in diameter. Two main branches bifurcate from a short stem, 7.5 mm in diameter, producing secondary branches that subdivide again at distances of 5-50 mm apart. The branches split at angles of 45° to 90°. The branches are 6-9 mm in diameter and little tapered toward the tips. The unbranched terminal ends are up to 28 mm long. The calyces are all around the branches, close together, not imbricate (Fig. 5B). They are elongated, sub-conical, projecting perpendicular to the branches, and directed upwards at smaller angles at the upper branches. The calyces reach up to 3 mm long with projecting spiny borders. The sclerites are all whitish to colourless (Fig. 5C). The outer coenenchyme and calycular sclerites are elongated with both ends sharp or with one end sharp and the other truncated or forked. They are unilateral spinous spindles, 0.33-1.5 mm long and 0.14-0.25 mm wide (Fig. 6A), the inner side with numerous small warts and the outer side with short spines. The spindles bordering the calyx are prickly spindles and modified leaf spindles, 0.3-0.475 mm long and 0.04-0.1 mm wide, with lateral or terminal spiny processes (Fig. 6B) that project beyond the calyx border, and elongated warty spindles, 0.41-0.7 mm long and 0.075 -0.1 mm wide (Fig. 6C). The axial sheath is mostly composed of tuberculate, irregular spindles, 0.195-0.25 mm long and 0.084-0.13 mm wide (Fig. 6D). Anthocodial sclerites 0.086-0.175 mm long and 0.034-0.075 mm wide (Fig. 6E).

Colour of the colony is white.

Habitat and variability.

The species has been found living on rocky bottoms, caves and outcrops at 10-13 m in depth. The colonies are mostly growing in one plane, but in some cases they extend in two or three planes (Y. Hooker pers. comm.) (Fig. 7A). The examined colonies are bushy, mostly with lateral and irregular branching subdividing up to 10 times. Some branch anastomosis occurs. Colonies reach up to 25 cm long by 21 cm wide and bifurcate up to 10 times, diameter of branches reaches up to 10 mm. Sclerites are as in the holotype. The colonies are infested with a polychaete species that perforates the axes, and are also colonised in some branches by small cirripedia.

Distribution.

Reported from Las Ánimas Islet, Gulf of California by Harden (1979) and Canoas de Punta Sal, Perú (Y. Hooker pers. comm.), and Mazatlán, México (J.L. Carballo pers. comm.). Type locality, Zorritos, Perú.

Remarks.

Verrill (1869) described this species with a single specimen that was infested by a parasitic worm; this is consistent with the YPM 1621a specimen (Fig. 7A). All the recently collected material from Perú by Y. Hooker (2011-2012) is also hosting the same polychaete (Fig. 7 A–B). We examined two small specimens from México that also show the tunnels and axial projections made by the worm.

Other material revised.

MÉXICO. M 18, dry, Punta Tiburón, Kino Bay, Sonora, 5.5 m, J.L. Carballo, 11 October 1999. PERÚ. CZA 286, dry, Canoas de Punta Sal, 12 m, Y. Hooker, 2 July 2011. CZA 412-416, 419, 424, dry, Canoas de Punta Sal, 13 m, Y. Hooker, 13 August 2012. CZA 286, Canoas de Punta Sal, 13 m, Y. Hooker, 2 July 2011. CZA 417-418, 420-423, Cabo Blanco, Piura, Y. Hooker, 13 August 2012. CZA 425, dry, El Ñuro, Piura, 10 m, Y. Hooker, 8 August 2012.