Muricea plantaginea (Valenciennes, 1846) Valenciennes, 1846

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 : 22-29

Taxon classification Animalia Alcyonacea Plexauridae

Muricea plantaginea (Valenciennes, 1846) comb. n. Figures 14, 15, 16, 17, 18, 19

Gorgonia plantaginea Valenciennes, 1846: pl 15.

Muricea plantaginea not Gorgonia plantaginea Lamarck, 1815: 163 (Antilles).

Muricea plantaginea not Eunicea plantaginea Valenciennes, 1855: 13; Milne Edwards and Haime 1857: 151

Eunicea tabogensis Duchassaing & Michelotti, 1864: 17.

Muricea appressa Verrill, 1864: 37; Verrill 1866: 329; 1868: 412; 1869: 444-446; Kükenthal 1919: 752; Kükenthal 1924: 145; Riess 1929: 390-391; Hardee and Wicksten 1996: 132-136 (syn. n.).

Muricea appressa var. flavescens Verrill, 1869: 446; Kükenthal 1919: 752; Kükenthal 1924: 145 (syn. n.).

Muricea tenella Verrill, 1869: 446-448; Kükenthal 1919: 752; Kükenthal 1924: 145; Hickson 1928: 371-372; Riess 1929: 389-390; Stiasny 1943: 72-74; Harden 1979: 160 (syn. n.).

Material.

Holotype. MNHN oct 0541, dry, Mazatlán, Mexico, Voyage sur la Frégate La Vénus, M.A. Du Petit Thouars, 1836-1839.

Other type material.

Muricea appressa : MCZ 381-384, 3950 (380), 3950A-B, ethanol preserved, Panamá, P.H. Sternberg, July 1863. USNM 33585, 33587, 44162, dry, Panamá, J.H. Sternberg, no more data found. Muricea appressa var. flabescens: YPM 1616A, Zorritos, Perú, 5-9 m, F.H. Bradley, 1866-1867. MCZ 705; YPM 1179A-D, USNM1130760 (YPM 1616), dry, Pearl Islands, Gulf of Panamá, F.H. Bradley, 1866-1867. Muricea tenella : YPM 1617A-B MCZ4978 (708), dry, Zorritos, Perú, F.H. Bradley, 1867. YPM 1180B, dry, Pearl Islands, Panamá, F.H. Bradley, 1866. YPM 1657, ethanol preserved, Pearl Islands, F.H. Bradley, 1866.

Description.

The holotype is a large, flabelliform colony 40 cm tall and 18 cm wide. The colony is in bad shape, the main branches are almost nude and branchlets are bent to the sides (Fig. 14B). However, from Valenciennes´ illustration (Fig. 14A) it is possible to tell the flabelliform original aspect. A thick, 4.32 cm main branch arises from an irregular holdfast 5.29 cm in diameter, then bifurcates 6 cm above the base, producing two secondary branches 10-12 mm in diameter. One secondary branch is broken and the other subdivides many times into 4-3 mm wide branches which subdivide in an irregular manner producing branchlets 2-3 mm in diameter. Branchlets closely placed, about 10-15 mm apart, mostly at angles of 30°-45°. Unbranched terminal ends are 10-20 mm long. Calyces are small, 0.7-1 mm long from the base to the tip, with elongated lower borders curved inwards. Calyces are numerous, very close together and imbricate, 10-20/cm around the branchlets and more crowded and smaller at the branches. Coenenchyme is thin. Calycular and coenenchymal sclerites are reddish-brown and amber (Fig. 14 D–E). Coenenchymal and calycular sclerites are mostly reddish-brown leaf-like spindles, 0.22-1.0 mm long and 0.09-0.20 mm wide (Fig. 15A), and amber elongated warty spindles 0.24-0.53 mm long and 0.06-0.10 mm wide (Fig. 15B). The axial sheath is composed of spindles, with single or bifurcated ends and radiates, 0.10-0.3 mm long and 0.05-0.09 mm wide (Fig. 15C). Anthocodial sclerites are lobed and warty rods, 0.06-0.23 mm long and 0.02-0.05 mm wide (Fig. 15D).

Colour of the colony is deep brown.

Habitat and variability.

Verrill´s type series is very consistent in all characters with respect to the Valenciennes’ holotype. For example, the specimen MCZ 3950 (Fig. 16 A–C) shows the flabellate colony with imbricate calyces, and the types and colours of the sclerites (Fig. 16C) matching the holotype. Some colour variation was found in the syntypes of Muricea appressa var. flavescens and Muricea tenella that are herein considered synonyms of Muricea plantaginea . The colony colour varies from lighter hues of brown to yellowish or whitish as in the former Muricea apressa var. flavescens and Muricea tenella (Figs 17 A–B, 18 A–B), and also sclerites colour is whitish in these varieties (Figs 17C, 18C). Variation in sclerite’s size was observed in some specimens respect to the holotype, the leaf-spindles could be shorter (about 0.50 mm) and the warty spindles longer (about 0.70 mm). In living colonies, the polyps can be white or yellow (Fig. 19 B–D). Branches reach up to 15 mm in diameter and branchlets up to 5 mm. Colonies could have thinner branchlets (less than 2.5 mm diameter) and longer unbranched terminal ends up to 15 cm long (Fig. 18A). Calyces could reach up to 1.2 mm long, density around branches and branchlets could vary 8-22 calyces/cm. Calyces are imbricate especially at the branchlets, more scarcely imbricate at thick branches or stems.

The species is widespread throughout the central archipelago of the Galápagos ( Breedy et al. 2009, Hickman 2008), and along the coast of Ecuador ( Rivera and Martínez 2011). The species is abundant in Bajo Lunes (coast of Ecuador, 18-20 m deep) where they grow on a flat rocky bottom covered by sand and thin grain sediment. The thin grain sediment suspends in the water column producing high turbidity. In this locality we have found the largest colony sizes, up to 1.20-1.30 m tall and 1.5 m wide (Fig. 19 A–B). In the Galápagos the colonies are of smaller size, around 0.5-0.6 by 0.5-0.70 m, and they are found deeper, down to 30 m on rocky bottoms and in clear water (Fig. 19C). Along the coast of Panamá the colonies do not reach more than a half-meter in size. The species reaches its deepest record, down to 65 m, at Hannibal Bank, off Panamá coast.

Distribution.

A widespread distribution, it has been reported from México to Perú, at a depth range from 10-65 m including the oceanic islands, Galápagos (Ecuador) and Revillagigedos ( México). Type locality: Mazatlán, México.

Remarks.

The species appears for the first time in Valenciennes’ book ( 1846) as Gorgonia plantaginea , apart from the illustration (Plate XV) of this species there is no description. The specimen MNHN oct 0541 matches Valenciennes´ drawing (Fig. 14 A–B). Verrill (1864) proposed the genus Muricea for this species, describing it as Muricea appressa , and properly described it in 1868, but overlooked the previous name that according to the ICZN has priority. Verrill (1869) also mentioned a variety of this species Muricea appressa var. flavescens based on some difference in colour and size of sclerites (Fig. 17). He also described Muricea tenella based on the slender branches, acute calyces and slender and sharp spindles ( Verrill 1869). However, he made these observations from one specimen (YPM 1617A) that out of the long untidy branches, do not present significant difference to be considered another species.

Other material revised.

COSTA RICA: UCR 591, dry, Pitahaya Beach, Guanacaste, 23 m, J. Cortés, 15 June 1991; UCR 634, dry, Las Cocineras, Santa Elena Bay, Guanacaste, at the beach, O. Piedra B., 20 February 1965; UCR 945, dry, Caño Island, 22 m, H. Guzman, 11 February 1984. USNM 49389, dry, San Lucas, Gulf of Nicoya, Puntarenas, M. Valerio, January 1st 1930. ECUADOR: CDRS 04-302-304, ethanol preserved, Punta Albemarle, Galápagos Islands, 20-22 m, C. Hickman, 29 November 2004; CDRS 06-32, ethanol preserved, Nameless Island, Galápagos Islands, C. Hickman, 25 May 2006. IIN 23,24, 27a, 27, 28, dry, Bajo Lunes, Salinas, 18 m, F. Rivera, P. Martínez, 21 July 2010; IIN 30, 31, 40, 63-65, 72, dry, Gigima, Salinas, 12-14 m, F. Rivera, P. Martínez, 22 July 2010; IIN 92, 124, dry, Los Ahorcados, Machalilla National Park, 10-12 m, F. Rivera, P. Martínez, 25 July 2010.

MÉXICO: CASIZ 099631, 097735, ethanol preserved, Roca Partida, Revillagigedo Islands, 36 m, R.J. Van Syoc, M/V "Royal Star, Clipperton Island Expedition 1994, 2 May 1994. MNHN oct, dry, Baja California, M.L. Piquet, 1898, no more data. M-Gorgonia7, dry, Islas Gringas, San Carlos Bay, Sonora, 5-25 m, J.L. Carballo, 27 November 2002. PANAMÁ: STRI 557, etanol preserved, Palito Afuera Island, 5-8 m, H. Guzman, 17 April 2003; STRI 778, Pedro Gonzales Island, 3 m, H. Guzman, 11 August 2003; STRI 829, 831, 833, San Telmo Island, 27 m, H. Guzman, 7 April 2004; STRI 902, 903, 906, Pedro Gonzales Island, 10 m, H. Guzman, 23 September 2004. USNM 34065, dry, Gulf of Panamá, Panamá Bay, no more data found.