Philarius polynesicus, Marin, Ivan & Anker, Arthur, 2011

Marin, Ivan & Anker, Arthur, 2011, A partial revision of the Philarius gerlachei (Nobili, 1905) species complex (Crustacea, Decapoda, Palaemonidae), with description of four new species, Zootaxa 2781, pp. 1-28 : 6-13

publication ID	https://doi.org/ 10.5281/zenodo.203049
DOI	https://doi.org/10.5281/zenodo.6183078
persistent identifier	https://treatment.plazi.org/id/5F3AF628-EF20-FF8E-738E-FB25FEB6FCA8
treatment provided by	Plazi
scientific name	Philarius polynesicus
status	sp. nov.

Treatment

Philarius polynesicus View in CoL n. sp.

( Figs. 4–8 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 , 9 View FIGURE 9 A–E)

(?) Philarius gerlachei Poupin 1998: 17 .

Type material. Holotype: 1 male, pcl 3.2 mm ( FLMNH UF Arthropoda 16148), French Polynesia, Society Islands, Moorea, S of Vaiare Pass, 17.5303 S 149.7621 W, outer reef slope, from Acropora valida , depth: 5–6 m, coll. C. Meyer, S. McKeon, G. Paulay, J. Moore, processed by A. Anker, 27.X.2008 (fcn BMOO 4574). Paratypes: 1 ovigerous female, pcl 4.5 mm ( FLMNH UF Arthropoda 16159), same data as for holotype (fcn BMOO 4588); 1 male, pcl 2.4 mm ( FLMNH UF Arthropoda 15924), French Polynesia, Society Islands, Moorea, Haapiti, SE of Matauvau Pass, 17.5779 S 149.8768 W, outer reef slope, from Acropora valida , depth: 6– 8 m., coll. S. McKeon, J. Moore, G. Paulay, processed by A. Anker, 21.X.2008 (fcn BMOO 3621).

Description. Medium-sized pontoniine shrimp with depressed body. Carapace smooth; antennal tooth sharp. Rostrum long, compressed, slightly descendant, with tip not reaching distal margin of scaphocerite blade; dorsal lamina with four to five relatively large dorsal teeth, most-posterior tooth situated anterior to orbit; most-distal portion of rostrum toothless; ventral lamina with single tooth situated at about 0.6 length of rostrum; proximolateral rostral lamina without supraocular lobe. Orbit with inferior orbital angle somewhat bluntly produced. Pterygostomial angle bluntly produced anteriorly.

Pleura of Abd1–5 rounded. Telson broad, about 2.2 times as long as proximal width, narrowing distally, with two pairs of small dorsal submarginal spines at 0.5 and 0.75 of telson length, respectively; distal margin armed with three pairs of spines, including one pair of short lateral spines, one pair of longer intermediate spines and one pair of median spines slightly shorter than intermediate spines.

Eyes as described for P. gerlachei .

Antennule with basal segment about as long as wide, distolateral angle with acute tooth; ventromesial tooth small, acute; proximal fused portion of lateral antennular flagellum with about 16 segments, accessory ramus with three or four segments. Antenna with basicerite bearing sharp distoventral tooth; scaphocerite about 2.5 times as long as maximal width; blade fairly broad, strongly convex distally; distolateral tooth strong, acute, reaching slightly beyond distal margin of blade.

Mouthparts typical for genus. Mandible robust, without palp; incisor process broad, with three large terminal teeth; molar process robust, with stout sharp teeth distally. Maxillule with well-developed palp; dorsal lacinia broad, slightly curved, flaring distally, with stout setae along distal margin; ventral lacinia more slender, tapering distally, with simple setae. Maxilla with well-developed, simple, distally pointed palp, with slender single endite furnished with long simple stiff setae; scaphognathite well developed. First maxilliped (= Mxp1) with completely fused endites, exopod well developed, broad, with feebly developed caridean lobe; epipod ear-shaped. Second maxilliped (= Mxp2) with well-developed, broad exopod; propodus with straight distolateral margin covered with simple setae; dactylus narrow, about four times as long as broad; epipod square-shaped. Third maxilliped (= Mxp3) as described for P. gerlachei .

P1 as described for P. gerlachei . P2 subsymmetrical in shape, subequal in size, robust; surface of distal segments covered with numerous simple setae; carpus cup-shaped, flaring distally, with two subtriangular blunt teeth ventrally, distodorsal margin rounded; palm subcylindrical, about three times as long as wide, smooth; fingers robust, about three times as long as wide, more than half-length of palm, with acute, curved tips; cutting edges bearing six to eight small triangular teeth along approximately 0.7 of their length; rounded depression present on ventroproximal portion of dactylus.

P3–5 similar in general shape, robust; P3 with ischium, merus and carpus unarmed, covered with simple setae; propodus about 3.5 times as long as wide, with straight lateral margins, with three tufts of long simple setae along distoventral margin and one long row of simple setae on distal margin; dactylus simple, stout, strongly curved, distally acute.

Uropods fairly slender, slightly exceeding telson; distolateral tooth and spine subequal in length, moderately strong.

Colour pattern. Body semitransparent, pale yellow-greenish or pale yellow, with small dark brown or blackish spots dorsally on carapace, first and sixth abdominal somites, and proximal portion of telson; in females, carapace and first two or three abdominal somites also with whitish paches; P1 and P3–5 uniform pale yellow-greenish, with more or less marked brownish longitudinal line on each article, areas near articulation conspicuously pale-yellow or whitish; P2 pale yellow-greenish, markedly paler near articulations, and with some brown spots on distal portions of merus and carpus, and most-proximal and most-distal portions of palm; propodo-dactylar articulation more conspicuously orange-brown; finger cutting edges olive-green proximally; antennular and antennal flagella pale orange-yellow; corneas blackish; inner organs partly visible through carapace, greenish and brown ( Fig. 9 View FIGURE 9 A– E).

Etymology. Referring to French Polynesia, a French overseas territory that includes Moorea, the type locality of this new species; used as adjective.

Ecology. All specimens were extracted from colonies of Acropora valida (Dana) , collected at a depth range of 5– 8 m.

Distribution. Presently known only from the type locality in Moorea, Society Islands, French Polynesia; perhaps also in Mururoa ( Poupin 1998, as P. gerlachei ).

Remarks. Philarius polynesicus n. sp. is closely related to P. gerlachei , differing from it only by the broader scaphocerite blade (cf. Figs. 2 View FIGURE 2 E, 5G); the broader telson, with more anteriorly positioned dorsal spines (cf. Figs. 2 View FIGURE 2 F, 7B); the lesser number of segments in the fused portion of the lateral antennular flagellum (around 16 in P. p o l y n e - sicus n. sp. vs. 25 in P. gerlachei , cf. Figs. 2 View FIGURE 2 B, 7C); and the longer toothless terminal portion of the rostrum (cf. Figs. 3 View FIGURE 3 A–D, 5A–E). The new species also lacks dark dorsolateral spots on the abdomen illustrated by Bruce (1982) in a specimen of P. gerlachei from the Great Barrier Reef. Philarius polynesicus n. sp. can be distinguished from the three below-described species by the same criteria as P. gerlachei [see Table 1 and Remarks under species described below].