Laomenes tigris Marin, 2009, sp. nov.
Creators: name: Marin, Ivan
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Palaemonidae
Laomenes
Laomenes tigris

description: Laomenes tigris sp. nov.
(Figs. 20–24)
Periclimenes ceratophthalmus. — Kemp, 1925: 324, fig. 18 [not P. ceratophthalmus Borradaile, 1915].
Material. ovigerous female holotype (pcl. 6.5 mm) (ZMMU), 1 paratype male (pcl. 4.5 mm) (ZMMU), Mun Island, Nhatrang Bay, Vietnam, 15–20 m, on crinoid № 38 (Stephanometra sp), 28.iii.2007, coll. E. Mehova, T. Britayev.
Description. Holotype female: Carapace swollen, smooth, with antennal and hepatic teeth (Fig. 20 A); hepatic tooth triangular, larger than antennal; antennal spine small, slender, slightly turned upward (Fig. 20 A, C). Rostrum long, slender and straight, slightly compressed, with well developed dorsal carina bearing 6 large teeth and 1 subapical tooth, ventral carina feebly developed, toothless. Lateral rostral lamina feeble in distal and medial parts, with well developed proximal part forming large supraocular teeth (Fig. 20 B). Orbit well developed, inferior orbital angle slightly produced, rounded distally. Pterygostomial angle projected, rounded.
Abdominal somites smooth; pleura of abdominal somites I–V rounded. Telson about 2.5 times as long as wide in proximal part (Fig. 22 C), gradually narrowing posteriorly, with 2 pairs of small dorsal spines arising close to lateral margin at 0.55 and 0.8 of telson length; 3 pairs of posterior spines containing short stout lateral, long slender intermediate and slender submedial spines slightly longer than the half of the length of former spines (Fig. 22 D).
Eyes large and well developed (Fig. 20 D); eyestalk about 1.5 times as long as wide; cornea highly produced in central part, with greatly produced stout blunt apical papillae. Well marked accessory pigmented spot presents posterodorsally.
Antennule (Fig. 22 A) well developed; basal segment about twice longer than wide, distolateral margin with short triangular acute distolateral tooth and rounded medial projection; submarginal ventral tooth distinct, situated near medial border of basal segment; stylocerite well developed; intermediate segment stout, as long as wide, with distolateral margin slightly produced; distal segment about as long as wide.
Antenna (Fig. 22 B) well developed, basicerite with large acute distoventral tooth; carpocerite stout, about 1.5 times longer than wide; scaphocerite about twice as long as maximal width, overreaching intermediate antennular segment, with well developed acute distolateral tooth, not reaching distal margin.
Epistomial horns well developed, sharp (fig. 20E). Mandible robust (Fig. 21 A), without palp; incisor process well developed, broad, shove-like, with 1 sharp large and 8 or 9 small terminal teeth (fig. 21B); molar process well developed, robust, with distinct sharp teeth distally. Maxillule (Fig. 21 C) normal, with well developed bilobed palp; upper lacinia slightly curved, flaring distally, with strong setae distally; lower lacinia stout, flaring distally, with strong distal setae. Maxilla (Fig. 21 D) with simple pointed palp; endites well developed, slender, furnished with stiff, elongated setae; scaphognathite well developed, edging with plumose setae. Maxilliped I (Fig. 21 E, F) with fused endites bearing setae along lateral margin; exopod well developed, slightly flaring distally, with large caridean lobe edging with plumose setae; epipod triangular, bilobed. Maxilliped II (Fig. 21 G) with well developed exopod; distolateral margin of propodus broadly rounded, situated angularly to dactylar segment, with moderately developed dorsolateral margin, with slender setae; dactylus about 1.5 times longer than broad, with numerous spines along distal margin; epipod subovate; podobranch absent. Maxilliped III (Fig. 21 H) with slender segments; ischiomerus with concave lateral margin, about 5 times as long as maximal width; penultimate segment slender, about 3 times longer than wide; terminal segment slender, about 3 times as long as wide, with tufts of sparse long setae along ventral margin; exopod broad and slightly exceeding ischiomerus; epipod ovate; small arthrobranch present.
Pereiopod I (Fig. 23 A) slender, with slender chela and fingers; coxal segment with distinct lobe distoventrally; basis robust, ischium is about 5 times longer than wide; merus slender, about 10 times as long as wide; carpus slender, longer than merus, about 12 times as long as wide, slightly flaring distally, with well developed distal setae at carpo-propodal articulation; palm about 3 times longer than wide, subcylindrical; dactylus and fixed finger curved, very slender, tapering to tips, with entire cutting edges and simple tips (Fig. 23 B).
Pereiopod II similar in size and shape (see Fig. 24 A), but right was missed during preservation. Segments of left pereiopod II robust (Fig. 23 C); palm cylindrical, about 2.5 times as long as maximal width; fingers robust, about 4 times as long as wide, with small numerous teeth along cutting edges and acute, curved tips (Fig. 23 D).
Pereiopod III (Fig. 23 E) slender, with segments unarmed; ischium about 2.5 times as long as wide; merus about 4 times longer than wide; carpus about 4 times as long as maximal width, slightly tapering proximally; propodus about 5.5 times as long as wide, with straight and smooth margins, without distoventral teeth, with tufts of long slender setae along distoventral margin and row of plumose setae distally; dactylus (Fig. 23 F) robust, as long as maximal width, with large, acute, sharp unguis; accessory tooth large, turned down; tuft of long slender setae situated at the middle of dactylus. Pereiopods III–V similar.
Pleopods normal (Fig. 22 F). Uropods slender, exceeding telson; distolateral margin of uropodal exopod with small distal tooth and mobile spine (Fig. 22 E).
Paratype male: Generally similar to holotype female, differing slightly in rostral formula, 6/0 (Fig. 20 F, G). Pereiopods II more robust (Fig. 23 G); fingers robust, about 4 times longer than wide, with curved, acute tips, with three large triangular teeth on dactylus and 4 large triangular teeth on fixed finger (Fig. 23 H). Appendix interna longer than appendix masculina (Fig. 22 H), with numerous subterminal cincinnuli. Appendix masculina with 2 long terminal and 2 subterminal plumose setae, with lateral border bearing 3 simple spines along lateral margin.
Coloration. General background of the body in females white (Fig. 24 A); carapace with 2 black longitudinal bands laterally, 4 complete and 1 incomplete transverse bands dorsally; abdomen is transversed with black bands continuing to pleura, but not edging them; abdominal somite I with black incomplete transverse band dorsally; somites II–V with 2 black transverse bands dorsally; rostrum, eyestalks, stalks of antennule and antenna, pereiopods I–V, telson and uropods brown-yellow. Males are generally transparent (Fig. 24 B); rostrum, eyestalks, stalks of antennule and antenna, articulations of pereiopods I–V, telson and distal margin of uropods yellow or dark yellow; distodorsal part of carapace and dorsal surface of abdominal somites dirty whitish.
Remarks. The species clearly differs from the other species of the “ L. jackhintoni ” group, L. jackhintoni (Bruce, 2006), by its straight rostrum with well developed dorsal carina (vs. sickle-like rostrum with feebly developed dorsal carina in L. jackhintoni), stout and distally rounded apical corneal papilla (vs. slender and acute tapering apical papilla in L. jackhintoni), rounded distal margin of medial projection on distolateral margin of basal antennular segment (vs. sharp pointed in L. jackhintoni) and presence of 8 rows of simple setae along distoventral margin of pereiopod III. The distinguishing features of the coloration of Laomenes tigris sp. nov. are 4 complete and 1 incomplete thin dark transverse band on dorsal surface of carapace and 1 incomplete dark band on dorsal surface of abdominal somite I allowing clear identification of the species even in situ and on photos. Laomenes tigris sp. nov. was previously misidentified with Laomenes ceratophthalmus (e.g., Bruce 1978, 1983). For its distinguishing features see “Remarks” in description of L. ceratophthalmus (below).
Host. The specimens of the species were collected from mariametrid crinoid identified as Stephanometra sp. (Crinoidea, Mariametridae).
Etymology. The species is named on the basis of a similar banded coloration to the Old World felid cat, the Tiger, Panthera tigris (Linn.) (Mammalia, Felinidae).
Distribution. The species is only known from the type locality (Vietnam) and the Maldive Islands (Kemp 1925). Photos on the world-wide-web suggest a wider distribution of the species: Indonesia, the Philippines, Fiji and Christmas Island (Fig. 24 C–F). Some of specimens described as L. ceratophthalmus by Okuno & Fujita (2006: fig. 2, ovigerous female (CMNH–ZC 02071)) from Japan probably refer to Laomenes tigris sp. nov.
description: Published as part of Marin, Ivan, 2009, Crinoid-associated shrimps of the genus Laomenes A. H. Clark, 1919 (Caridea: Palaemonidae: Pontoniinae): new species and probable diversity, pp. 1-49 in Zootaxa 1971 on pages 25-33, DOI: 10.5281/zenodo.185020