Leptogorgia cortesi, Breedy, Odalisca & Guzman, Hector M., 2012

Breedy, Odalisca & Guzman, Hector M., 2012, A new species of Leptogorgia (Cnidaria: Anthozoa: Octocorallia) from Golfo Dulce, Pacific, Costa Rica, Zootaxa 3182, pp. 65-68 : 65-67

Genus Leptogorgia Milne Edwards & Haime, 1857

Leptogorgia cortesi sp. nov.

Holotype: MZUCR 2118, ethanol preserved, Punta Islotes, Golfo Dulce, 9 m, O. Breedy and J. Cortés, 11 April 1997.

Paratypes: MZUCR 2119–2127, 2130–2135, same data as the holotype; MZUCR 2128–2129, ethanol preserved, Punta Estrella, Golfo Dulce, 25–30 m, O. Breedy and H.M. Guzman, 5 February 2009; MZUCR 2147, dry, Punta Islotes, Golfo Dulce, 14 m, J. Cortés, 20 January 1994.

Description. The holotype is a bushy, irregular looking colony 11.2 cm long and 15.5 cm wide ( Fig. 1 A–B), arising from a conical holdfast, 15 mm in diameter, spreading over solid substrate. The colony is laterally branched; three primary branches arise from a very short basal stem, 3 mm in length and 2.5 mm in diameter. The branches, 2–2.5 mm in diameter, produce secondary branchlets, 1–1.5 mm in diameter, irregularly subdividing up to seven times. Some branchlets form pseudo-anastomoses (anastomosis of the coenenchyme, not of the axes). The unbranched final twigs are long, slender, and sprout at a wide angle; they shortly curve upward roughly parallel with the larger branches or extend perpendicularly. The twigs reach up to 6 cm in length, 0.5–1 mm in diameter, and have pointed tips. A narrow, marked, sinuous groove extends along the main stem and the branches and branchlets, but it may be indistinct or absent on the distal portions of the latter. The axis is horny, with a chambered central core filled with organic filaments mineralized with microspheres of carbonate hydroxylapatite. The polyps are retracted into surface mounds that are closely distributed, prominent, and about 0.3–0.5 mm tall; they are mostly arranged in two alternating rows on each side of the thicker branches, and in a single row on each side of the branchlets. The edge of the distal part of the branches shows an undulating, delicate contour, which is very distinctive for the species ( Fig. 1 A).

Sclerites of the coenenchyme are colourless; the longer ones are spindles ( Fig. 1 C), some slightly curved, with up to 12–14 whorls of tubercles, and up to 0.16 mm long and 0.048 mm wide. They have acute tips, one of which can be slightly bent or bifurcated. There are also transitional forms between a capstan and a spindle, with various arrangements of tubercles and warts ( Fig. 1 C). The shorter sclerites are tuberculate capstans, with two whorls of warty tubercles and complex terminal clusters, ranging from 0.029–0.075 mm long and 0.019–0.04 mm wide ( Fig. 1 D). A small number of crosses are present, up to 0.06 x 0.06 mm long, with tuberculate arms ( Fig. 1 E). The polyps are colourless. The anthocodiae have a weak, point-like arrangement of long and narrow, somewhat flattened rods with lobed or indented margins that are sparsely covered with low warts, more concentrated at the ends of the longer rods. The anthocodial rods are up to 0.12 mm long and 0.03 mm wide ( Fig. 1 F), and are colourless.

Colour of the colony is white.

Distribution. Presently, the species has been found only at the inner rocky coralline reefs of Golfo Dulce.

Etymology. The species is named after a long time friend and colleague Jorge Cortés, who first suggested to us to adopt octocorals as a topic of study, and we hereby acknowledge him as a pioneer of marine biodiversity research in Costa Rica.

Discussion. The new species belongs to the Leptogorgia alba -group which unites the species that have white colonies, variable branching pattern, mostly lateral, and polyp-mounds varying from flat to slightly prominent ( Guzman & Breedy 2008). There are six valid species in the Leptogorgia alba -group, the new species differing from the others by having the following unique combination of characters. Firstly; ramifications can be up to seven times; and a few pseudo-anastomoses occur in some parts. Secondly, the polyps retract in prominent mounds that are closely arranged, giving an undulating appearance to the edges of the branches. Finally, the maximum length of spindles is 0.16 mm, having 12–14 whorls of tubercles and frequently a bent end. See Table 1 for details.

Species Polyps Growth form Sclerites (*) white variety

polyp mounds: p, prominent; sr, slightly raised; f, flat branching tendency: fla, flabellate/; bu, bushy; asc, ascending and whip-like type of branching: lat, lateral; s-lat, sparsely lateral; d-lat, densely lateral; pi-lat, lateral with irregular pinnate branches branch form: st, stout; sl, slim

present: ν; absent: X

Figures

FIGURE 1. Holotype of Leptogorgia cortesi: A, close up view of branches; B, entire colony; C – E, coenenchymal sclerites; F, anthocodial rods.

Tables

TABLE 1. Comparative characteristics of the Leptogorgia alba - group.

L. alba Duchassaing & Michelotti	mounds Polyp sr	form Colony fla	branching of Type lat	form Branch st	of # bifurcations Maximum 4	anastomosis abundant type Pseudo- Most sclerite X spindle	mm 0.1> Spindles ν	length spindle. mm Max in 0.18	spindles Bent ν	max mm rods in. length Anth 0.15
L. cofrini Breedy & Guzman	sr	bu	d-lat	st	4	X spindle	ν	0.12	X	0.14
L. peruviana (Verrill)	f	bu	d-lat	st	4	X capstan	X	0.10	X	X
L. laxa Hickson	sr	asc	s-lat	sl	2	X spindle	ν	0.18		0.10
* L. ramulus (Milne Edwards & Haime)	p	bu	pi-lat	st	5	X capstan	ν	0.13	X	0.09
L. styx Bayer	f	fla	lat	st	4	X spindle	ν	0.15	ν	X
L. cortesi sp. nov.	p	bu	lat	sl	7	ν spindle	ν	0.16		0.12