Periclimenes josephi, Li, 2008

Li, Xinzheng, 2008, Report on some species of Palaemonidae (Crustacea, Decapoda) from French Polynesia, Zoosystema 30 (1), pp. 203-252 : 224-230

Periclimenes josephi n. sp.

( Figs 11-14 )

TYPE MATERIAL. — Austral Is. Neilson Reef, BEN- THAUS, stn CP 1918, 27°03.4’S, 146°04’W, 130-140 m, 11.XI.2002, ovig. ♀ holotype (cl 3.02 mm), ovig. ♀ paratype (cl 2.28 mm) (MNHN-Na 15980). — Stn CP 1920, 27°03.6’S, 146°03.8’W, 120-203 m, 11.XI.2002, 1 ♂ paratype (cl 2.21 mm) (MNHN-Na 15983). — Stn CP 1921, 27°03.7’S, 146°03.8’W, 150-160 m, 11.XI.2002, 1 ♂ paratype (cl 2.15 mm) (MNHN-Na 15986). — Northeastern Bank off Rapa, stn CP 1907, 27°25.4’S, 144°02.6’W, 120-125 m, 9.XI.2002, 1 ♂ paratype (cl 2.68 mm), 4 ovig. ♀♀ paratypes (cl 2.32- 3.10 mm) (MNHN-Na 15979).

ETYMOLOGY. — The specific name is given in honour to Joseph Poupin, for his contribution to carcinological studies in French Polynesia.

DISTRIBUTION. — Only known from the localities of the type material in French Polynesia (Austral Is) ; 120-203 m depth.

Palaemonidae ( Crustacea, Decapoda ) from French Polynesia

DESCRIPTION

A small sized pontoniine shrimp of subcylindrical body form.

Carapace smooth, glabrous. Rostrum well developed, slightly anteroventrad, bilaterally compressed, extending slightly beyond distal end of antennular peduncle, near to distal margin of scaphocerite (females), or near to distal end of antennular peduncle (males), subequal to carapace length; dorsal margin with 7 or 8 (usually 7) acute teeth, sub-evenly distributed along whole length, posterior 1 or 2 (usually 1) situated on carapace posterior to orbital margin, posteriormost epigastric, slightly smaller than anterior teeth, situated at anterior 0.10-0.22 (average 0.16) of carapace length; lateral carinae developed; ventral margin with 1 acute tooth at about distal 0.4 of rostral length, below and between anterior second and third dorsal teeth; interdental spaces of dorsal teeth and proximal ventral carina with setae. Orbit well developed, inferior orbital angle produced as triangular lobe, tip not acute; supraorbital spine absent; antennal spine slender and acute, sub-marginal, distant below to inferior orbital angle, extending to tip of inferior orbital angle; hepatic spine similar to antennal spine, slender and acute, below level of antennal spine, at, or slightly posterior or anterior to level of epigastric spine, base of hepatic spine with distinct suture; anterolateral angle of carapace not produced, bluntly rounded.

Abdominal segments smooth, glabrous; third segment with tergum normal, without dorsally compressed process; sixth segment about 0.5 of carapace length, 1.7 times length of fifth, subcylindrical, about 1.4 times longer than deep, posterolateral lobe with tip acute, posteroventral angles blunt; pleura of first 3 segments broadly rounded, fourth and fifth posteriorly produced, posterolateral lobes rounded. Telson about 1.5 times of sixth abdominal segment length, 3.2 times longer than anterior width, with 2 pairs of small dorsolateral spines at about 0.48 and 0.71 of telson length, spines about 0.06 of telson length; posterior margin posteriorly produced, with median point, with 3 pairs of posterior spines, lateral spines small, similar to dorsal spines, intermediate spines long, robust, about 0.26 of telson length, submedian spines extending to about proximal 0.42 of intermediate spine length.

Eye well developed, with globular cornea, diameter of cornea 0.3 of posterior orbital carapace length, distinctly stouter than stalk, with distinct accessory pigment spot; stalk short, about 0.75 of corneal diameter, subequal to width, without tubercle.

Antennular peduncle with proximal segment depressed, medial length about 0.45 times as long as carapace, 1.8 times longer than its central width, lateral margin feebly convex, with long strong acute distolateral tooth, overreaching level of produced anterolateral margin, near to distal margin of intermediate segment, medial margin straight, with small ventromedial tooth at about 0.4 of medial length of proximal segment; stylocerite acute, reaching to about 0.5 of proximal segment length; intermediate segment 0.3 of proximal segment length, 1.1 times of maximum width, lateral margin expanded laterally, setose; distal segment cylindrical, subequal to intermediate segment, about 1.7 times longer than wide; upper flagellum biramous, with four or five proximal segments fused, fused portion about 0.34 of carapace length, shorter free ramus with 3 segments, with 7 groups of aesthetascs; longer ramus slender, filiform; lower flagellum slender, filiform. Antennal basicerite robust, with acute lateral tooth; scaphocerite well developed, exceeding tip of rostrum, about 0.8 times as long as carapace, 3.3 times longer than wide, distal margin strongly produced, rounded, overreaching distolateral tooth, lateral margin feebly concave, with strong acute distolateral tooth; carpocerite about 0.37 of scaphocerite length, 3.0 times longer than wide; flagellum well developed, slender, about 5.0 times of carapace length.

Epistome unarmed. Fourth and fifth thoracic sternites each with posterior transverse carina with median notch; posterior sternites unarmed.

Mouthparts typical of the genus.Mandible without palp; molar process normal, with 4 strong blunt teeth, upper inner tooth low, plain, lower and inner margins of molar process with short and fine setae; incisor process obliquely truncate distally with three stout acute teeth, central tooth smaller than outer teeth. Maxillula with palp twisted, simple, not bilobed; upper lacinia slightly expanded, distal margin with simple spines and numerous short setae; lower lacinia up-curved, with numerous setae and slender distal spines laterally. Maxilla with short simple non-setose palp; basal endite deeply bilobed, upper lobe stouter than lower, with simple setae distally; scaphognathite well developed. First maxilliped with palp slender, with a distal spiniform seta; basal endite large, broadly rounded, medial margin with spiniform and simple setae; coxal endite obsolete; exopod large, well developed, caridean lobe large, broad, flagellum slender with 3 plumose distal setae; epipod large, triangular, deeply bilobed. Second maxilliped with normal endopod, dactylar segment about 3.8 times longer than broad, with numerous serrulate spines medially; propodal segment broad, distal margin with numerous long finely serrulate spiniform setae; exopod with 4 long setae distally; epipod simple, long, without podobranch. Third maxilliped with endopod extending to end of carpocerite, ischiomerus and basis fused, combined segment compressed, about 0.4 times of carapace length, 6.5 times longer than central width, setose medially; penultimate segment compressed, about 0.6 of combined segment length, 4.3 times longer than proximal width, with long spiniform setae medially; terminal segment about 0.45 of combined segment length, distally tapering, 4.6 times longer than proximal width, with long spiniform and short simple setae along entire length; exopod slender, about 0.7 of combined segment length, extending to 0.85 of combined segment length, with 4 setae distally; coxa with oval lateral plate; without arthrobranch.

Pereiopods slender. First pereiopods exceeding carpocerite by chela and carpus, exceeding distal margin of scaphocerite by chela and distal fourth of carpus; palm slightly compressed, about 0.26 times of carapace length, 2.2 times as long as maximum depth, ventral margin with 4 transverse rows of short cleaning setae on proximal 0.3 of length; finger slightly shorter than palm, strongly spatulate, cutting edges sharp, proximal half entire, distal half and tips with pectinate short setae, tips rounded; outer surfaces surrounded by clusters curved setae, carpus elongate, slightly swollen distally, about 2.6 times of palm length, 7.4 times longer than distal width, with a row of serrulate cleaning setae distoventrally corresponding those on palm; merus about 2.4 times of palm length, 7.4 times longer than wide; ischium about 1.1 of palm length, 3.2 times longer than wide, with several long setae medially; basis and coxa with medial processes, tips with setae.

Second pereiopods subequal and similar, slender, smooth, glabrous, exceeding carpocerite by chela, carpus and distal half of merus, exceeding distal margin of scaphocerite by chela and almost all carpus; palm subcylindrical, slightly compressed, subuniform, about 0.8-1.0 times of carapace length, 4.6 times longer than deep; fingers about half of palm length, tapering distally, with strongly hooked tips, cutting edges sharp, proximal 0.3 with 1 very small, low tooth on dactyl and 1-3 similar teeth on fixed finger, distal 0.7 of cutting edges entire, outer surface of fingers surrounded with long curved setae; carpus about 0.6 times of palm length, distinctly tapering distally, about 3.2 times of distal width, unarmed; merus subcylindrical, subuniform, about 0.9 of palm length, 6.2 of the central width, with a stout distoventral tooth laterally; ischium subequal to merus, very slightly tapering proximally, about 6.7 times longer than distal width; basis and coxa normal.

Third pereiopod exceeding carpocerite by dactyl, propod and distal half of carpus, exceeding distal margin of scaphocerite by dactyl and distal half of propod; dactyl short and stout, compressed, about 0.13 of propod length, unguis distinct, short and stout, about 0.4 of corpus length, corpus about 2.4 times longer than proximal depth, ventral margin nearly straight, distal accessory tooth minute but distinct; propod slightly compressed, subuniform, about 0.8 of carapace length, 12.0 times longer than deep, with pair of long and slender simple distoventral spines, spines about 0.04 of propod length, 0.35 of dactyl corpus length, ventral margin of propod with about 8 single spines similar to distoventral spine along entire length of propod, distal 4 spines more closely distributed than proximal spines, subequal to distoventral spines in length, proximal spines becoming gradually shorter proximally, distodorsal margin with several long setae, distolateral margin with short setae, distal fourth of ventral margin with dense fine woolly setae, other surfaces of propod with sparse short setae; carpus about half of propod length, slightly tapering proximally, 5.3 times longer than distal width, distodorsal margin with produced lobe; merus subcylindrical, subuniform, slightly shorter than propod, 9.2 times longer than central depth, distoventral margin with short stout tooth laterally, medial side unarmed; ischium about half of propod length, 4.5 times longer than distal width, slightly tapered proximally; basis and coxa without special features. Fourth and fifth pereiopods similar to third, fourth propod slightly longer than third, fifth propod 1.1 times as long as third; fifth exceeds carpocerite by dactyl and distal 0.6 of propod.

Uropod distinctly exceeding telson, extending near to tip of median posterior spines of telson; protopodite with posterolateral angle rounded; exopod about 0.7 times as long as carapace length, 2.9 times longer than central width, lateral border nearly straight, with slender and acute mobile spine medial to distal tooth (holotype with 2 mobile spines on right exopod), diaeresis indistinct; endopod narrow, slightly shorter than exopod, about 3.7 times longer than wide.

A

Egg number about 50, size moderate, maximum length 0.62 mm.

REMARKS

In the genus Periclimenes , P. josephi n. sp. is most similar to P. priodactylus Bruce, 1992 , with the hepatic spine having a basal suture, the fingers of the first pereiopod being strongly subspatulate. It can be easily distinguished from the latter by the well developed cornea, which is wider than the stalk (in P.priodactylus , the stalk is about 1.2 times wider than the corneal diameter); the cutting edges of the first pereiopod fingers are armed with very fine and short pectinate setae along the distal half of the cutting edge (in P. priodactylus , the cutting edges are entire); the second pereiopods are long and slender, the palm is about 0.8-1.0 times of the carapace length, the carpus is about 0.6 times of the palm, 3.2 times of its distal width, the merus has a stout acute lateral distoventral tooth (in P. priodactylus , the chela of the second pereiopod is about 0.72 times of the carapace length, the carpus is short and stout, about 0.45 times of the palm length, 1.4 times longer than its distal width, the merus is unarmed distally); the ventral margin of dactylar corpus of the third pereiopod is entire, the ventral margin of the propod bears dense fine woolly hairs along the distal fourth of the propod length, the merus bears a stout acute lateral distoventral tooth (in P. priodactylus , the ventral margin of dactylar corpus of the third pereiopod is armed with very acute, compressed serrations, the ventral margin of the propod lacks woolly hairs, the merus is unarmed distally). The features of the merus of the second pereiopod armed with a distoventral tooth, the biunguiculate dactyl and setose ventral margin of the propod of the third pereiopod in the new species appears similar to those of P. lanipes Kemp, 1922 . Periclimenes josephi n. sp. is distinctly different from P.lanipes by the hepatic spine having a distinct basal suture, the shape of the rostrum and the ratio and the form of the second pereiopod segments.

The hepatic spine on the carapace has a distinct basal suture, the spatulate fingers of the first pereiopod with the cutting edges of the fingers armed with short pectinate setae and the meri of the second and third pereiopods armed with a distoventral tooth, in the new species, resemble those of Zenopontonia noverca ( Kemp, 1922) . However, the hepatic spine is not completely mobile, the protopodite of the uropod with posterolateral angle is rounded, not produced and acute as that of Z. noverca , the pereiopods are more slender and longer that those of Z. noverca , and one or two rostral series teeth are situated on the carapace posterior to the orbital margin. Therefore, this new species is placed in Periclimenes , rather than in Zenopontonia .

Periclimenes paralcocki Li & Bruce, 2006 ( Fig. 15 )

Periclimenes paralcocki Li & Bruce, 2006: 707 , fig. 27.

MATERIAL EXAMINED. — Marquesas Is. Nuku Hiva, MUSORSTOM 9, stn CP 1303, 8°50’S, 140°19’W, 705-794 m, 9.IX.1997, 1 ♀ (MNHN-Na 15610).

DISTRIBUTION. — The species was previously only known from its type locality:Bayonnaise Bank, Tuvalu, at 600 m depth.

REMARKS

The soft rostrum and carapace show that the specimen was in ecdysis.However,the three pairs of dorsolateral spines on telson, the third pereiopod having the propod with spinules on flexor margin, and distal transverse rows of setae, the dactyl having the accessory tooth 0.31 of unguis length, indicate that the specimen belongs to this species. The holotype of the species lacked the major second pereiopod. The present specimen has the major second pereiopod ( Fig.15 ), which is very strong, large,covered with very fine tubercles on palm, outer surface of fixed finger, flexor margins of carpus and merus; the palm is 2.12 times as long as telson (soft carapace is unavailable for comparison with length), 4.32 times as long as its width; the fingers are 0.53 as long as palm, with strong lateral flanges, the tips are very hard, the cutting edges bear two teeth in proximal half respectively; the carpus is cup-like, 0.29 as long as palm, 1.59 times of its distal width; the merus is 0.53 of palm length, 3.85 as long as its width; the ischium is 0.50 as long as palm, 3.55 times of its width.

Figures

FIG. 11. — Periclimenes josephi n. sp., holotype ovig. ♀ (cl 3.02 mm) (MNHN-Na 15980), body, lateral view. Scale bar: 1 mm.

FIG. 12. — Periclimenes josephi n. sp., holotype ovig. ♀ (cl 3.02 mm) (MNHN-Na 15980): A, rostrum and carapace; B, telson; C, tip of telson; D, left eye, dorsal view; E, right antennule, dorsal view; F, left antenna, ventral view; G, left uropod; H, distal exopod of right uropod. Scale bars: A, D, 1 mm; B, C, E-H, 0.5 mm.

FIG. 13. — Periclimenes josephi n. sp., holotype ovig. ♀ (cl 3.02 mm) (MNHN-Na 15980): A, mandible; B, maxillula; C, maxilla; D, first maxilliped; E, second maxilliped; F, third maxilliped. Scale bars: 0.5 mm.

FIG. 14. — Periclimenes josephi n. sp., holotype ovig. ♀ (cl 3.02 mm) (MNHN-Na 15980):A, left first pereiopod; B, same, chela; C, right first pereiopod,fingers; D, right second pereiopod;E, same, fingers; F, left third pereiopod,medial view; G, same, distal merus, lateral view; H, same, dactyl and distal propod. Scale bars: A, B, D-G, 0.5 mm; C, H, 0.25 mm.

FIG. 15. — Periclimenes paralcocki Li & Bruce,2006,♀ (MNHN-Na 15610): A, major second pereiopod; B, same, fingers. Scale bar: A, 5 mm; B, 2 mm.