Pakistanapseudes baruna, Bamber, Roger N., 2013

Bamber, Roger N., 2013, Tanaidaceans from Brunei, IV. The Families Kalliapseudidae, Pagurapseudopsidae, Parapseudidae and Apseudidae (Crustacea: Peracarida: Tanaidacea: Apseudomorpha), with descriptions of a new genus and six new species, Zootaxa 3734 (4), pp. 401-441 : 420-424

Genus Pakistanapseudes Băcescu, 1978

Pakistanapseudes baruna sp. nov. Figs 10–12

Type material: 1 brooding ♀, holotype (BMNH 2013.840), 1 subadult ♂, 8♀♀ (one brooding), paratypes (BMNH 2013.841–848), Station B5, 04°51′06"N 114°35′26"E, 20 m depth, sand; March 2009. 1 subadult ♂, 12♀♀ (one brooding), 19 mancae, paratypes (BMNH 2013.849–858), Station B4, 04°51′06"N 114°35′26"E, 20 m depth, sand; March 2009. 3 subadult ♂♂, 9♀♀ (one brooding, one with oostegites), paratypes (BMNH 2013.859–868), Station B12, 04°51′06"N 114°35′26"E, 20 m depth, sand; March 2009. 3 subadult ♂♂, 12♀♀ (one brooding, one with oostegites), 5 neuters, paratypes (BMNH 2013.869–878), Station BU3, 04°51′06"N 114°35′26"E, 20 m depth, sand; March 2009. 6♀♀ (one brooding), paratypes (BMNH 2013.879–884), Site DA2, Station DA, 05°54′28.5"N 114°38′23.3"E, 20 m depth, sand; March 2009.

Other material: 9♀♀ (three brooding), 4♂♂; 1 brooding ♀, dissected, Station S5, 04°42′26.5"N 114°26′02"E, 11.5 m depth, sand. 2♀♀, Station S14, 04°42′39"N 114°26′24.6"E, 12.7 m depth, sand; coll. March 2009. 1♂, Station S17, 04°41′13"N 114°27′23"E, 6.5 m depth, sand; March 2009.

Description of female: Body ( Fig. 10 A), dorsoventrally flattened, elongate, 7.3 times as long as wide, holotype 3.4 mm long (tip of rostrum to posterior of pleotelson). Cephalothorax subrectangular, 0.9 times as long as wide, with pronounced flat rostrum, eyelobes distinct, pigmented. Pereonites with one or two fine lateral setae on each side. Pereonites 1 and 2 with convex lateral margins, 0.4 times as long as cephalothorax; pereonite 3 almost hexagonal, twice as long as pereonite 1; pereonite 4 rectangular, longest, 1.3 times as long as long as pereonite 3; pereonite 5 as long as pereonite 3, pereonite 6 half as long as pereonite 4 (all pereonites respectively 2.5, 2.2, 1.3, 1.0, 1.3 and 1.4 times as wide as long). Pleon about one third of whole body length, pleonites rectangular, 0.6 times as long as pereonite 6, and about 1.5 times as wide as long, each with three fine lateral setae on each side. Pleotelson subrectangular but distally rounded, about one quarter length of pleon, slightly longer than wide.

Antennule ( Fig. 10 B) proximal peduncle article 4.4 times as long as wide, outer margin with two proximal and one mid-length penicillate setae and row of longer simple setae in distal half, mostly submarginal; inner margin with two simple setae in proximal half and four more distally. Second article twice as long as wide, 0.4 times length of first, with few inner and more outer simple setae. Remaining articles and flagella not recovered.

Antenna ( Fig. 10 C) with naked proximal peduncle article. Second article three times as long as first, naked, elongate squama bearing eight marginal and two dorsal setae. Third article as long as first article, about half as long as wide, with two inner-distal spine-like apophyses. Fourth article about half as long as second article, naked; fifth article 1.4 times as long as fourth article, twice as long as wide, naked. Flagellum of nine segments, single aesthetasc present on fifth segment.

Labrum ( Fig. 10 E) rounded, simple, marginally setose; epistomal apophysis absent. Left mandible ( Fig. 10 F) with four rounded “teeth” on pars incisiva; lacinia mobilis with four rounded “teeth”; setiferous lobe with one trifurcate, two quadrifurcate and two simple setae; pars molaris stout, distally flat marginal flange; palp of three articles, proximal article with three inner setae, second article naked, third article with three distal setae. Right mandible as left but with without lacinia mobilis. Labium ( Fig. 10 G) with outer and distal setules, palp with inner and outer fine lateral setules and two simple distal setae, no inner apophysis. Maxillule ( Fig. 10 H) inner endite without subdistal apophysis, with five plumose distal setae; outer endite with eleven distal spines, outer margin finely setose distally; palp of two articles, distally with two setae. Maxilla ( Fig. 10 I) typical of genus, outer margin finely spinulose, moveable endite outer lobe with two subdistal setae and four finely-denticulate distal setae, inner lobe with five simple and two finely-denticulate setae; fixed endite outer lobe with simple, stout and bifurcate distal spines and one bilaterally denticulate subdistal spine, inner lobe with five longer setae and rostral row of 16 setae. Maxilliped basis and palp ( Fig. 10 J) with simple setae; first palp article with simple inner seta half as long as second article, one shorter and finer outer seta; second palp article with inner margin bearing numerous shorter curled setae and five longer setae, two outer distal setae of which longer almost reaches tip of fourth article; third palp article with six recurved inner setae; fourth palp article with four setae around distal margin and one subdistal seta. Endite ( Fig. 10 K) distal margin with outer simple setae and inner blunt spines, outer margin denticulate, with two coupling hooks. Epignath ( Fig. 10 L) large, subrectangular, with proximal lobes and distally-setulose spine.

Cheliped ( Fig. 11 A) slender. Basis nearly four times as long as wide, ventrally with fine spine in distal half, and single distal seta and proximal setae. Exopodite three-articled; article 2 naked, article 3 with three plumose setae. Merus attached to basis subdistally, with dorsal, ventral and inner proximal setae and ventrodistal group of five setae. Carpus very slender, 7.3 times as long as wide, ventrally with eight marginal and two submarginal setae, four inner setae along midline, two dorsodistal setae. Chela slender, palm 2.5 times as long as wide with single dorsodistal and two distal setae and simple seta at base of dactylus; fixed finger 1.4 times as long as palm, curved, with two ventral setae, cutting edge without apophyses but with six distal setae. Dactylus with three dorsal setae in proximal half, with six fine setules but no apophyses on cutting edge.

Pereopod 1 ( Fig. 11 B) basis 3.6 times as long as wide, with fine mid-dorsal seta and three ventrodistal setae, two exceeding distal margin of ischium, proximally with hook-like apophysis; exopodite three-articled, article 3 with three plumose setae. Ischium with two ventrodistal setae. Merus 0.6 times as long as basis, with five midventral setae, one ventrodistal spine with three adjacent setae, dorsally with one subdistal and three distal setae. Carpus compact, 0.75 times as long as merus, with two ventral spines amongst five marginal setae, one elongate, slender dorsodistal spine with two adjacent setae, dorsal margin with three setae, mid-distal margin with one seta. Propodus just longer than carpus, ventral margin with four spines interspersed with distally-tapering setae, dorsal margin with row of five tapering setae and one elongate, slender spine. Dactylus slender, with three ventral denticulations and dorsodistal seta, unguis distinct, minute, dactylus and unguis together 0.9 times as long as propodus.

Pereopod 2 ( Fig. 11 C) basis 3.5 times as long as wide, with three ventrodistal setae. Ischium almost as long as wide, with three ventrodistal setae. Merus one-quarter length of basis, with one mid-ventral and three ventrodistal setae and one ventral corrugated spine. Carpus 1.5 times as long as merus, with numerous ventral and distal setae and one ventral corrugated spine. Propodus as long as carpus, with eight ventral and distal setae. Dactylus slender with two fine distal setae, unguis minute, both together 1.2 times as long as propodus. Pereopod 3 ( Fig. 11 D) similar to pereopod 2, but all articles more slender and less setose, without corrugated spines.

Pereopod 4 ( Fig. 11 E) basis three times as long as wide with two dorsoproximal penicillate setae and one ventrodistal seta. Ischium with two ventral setae. Merus one-quarter length of basis, with four ventral and distal setae. Carpus 1.8 times as long as merus, with two mid-ventral setae and seven ventrodistal setae. Propodus 0.7 times as long as carpus, with one dorsal-subdistal and four distal simple setae, mid-dorsal penicillate seta, and four ventral setae surrounding corrugated spine. Dactylus slender with two fine distal setae, unguis minute, both together as long as propodus. Pereopod 5 ( Fig. 12 A) similar to pereopod 4, but carpus with ventroproximal and ventrodistal slender, corrugated spines. Pereopod 6 ( Fig. 12 B) similar to but stouter than pereopod 4, but carpus with ventrodistal slender, corrugated spine; propodus with ventral submarginal row of 12 short, lanceolate spines.

Pleopods ( Fig. 12 C) alike. Basis with four inner and three outer plumose setae; rami linguiform, exopod shorter than endopod and with 11 plumose setae along inner and distal margins; endopod with 13 marginal plumose setae, most-proximal two inner setae separated from others.

Uropod ( Fig. 12 D) biramous. Basis with three outer setae and two inner-distal setae with adjacent setule. Exopod of four segments; endopod missing on all specimens.

Subadult male: Generally similar to female. Cheliped and antennule not recovered. Antenna ( Fig. 10 D) with secondary segmentation of flagellum, without aesthetascs.

Etymology. Baruna is the Malay name for a god of the (celestial) ocean, from which word the name “ Brunei ” may have been developed (noun in apposition).

Remarks. Pakistanapseudes baruna sp. nov. shares a lack of setae on the second article of the mandibular palp only with the Brazilian species P brasiliensis , and the two Bass Strait species P. lucifer BłaŻewicz-Paszkowycz & Bamber, 2012 and P. taylorae BłaŻewicz-Paszkowycz & Bamber, 2012 . Unlike the present species, both of the Australian species have a dorsodistal spine on the merus of pereopod 1, and have distal extensions on the dactylus of pereopods 5 and 6 (and, in the case of P. lucifer , all other pereopods), giving an appearance of bifurcation; in addition, P. lucifer is without setae on the basis of its pleopods. P. brasiliensis has the dactylus plus unguis of pereopod 4 reduced, distinctly shorter than the adjacent distal propodal setae and proportionately shorter than the dactylus plus unguis on pereopod 5, whereas it is not reduced in P. baruna , being similar to that on pereopod 5; the Brazilian species also more distal setae on the maxillule palp and distinct setation of the maxilliped palp. None of those other three species has a mid-ventral spine on the basis of the cheliped.

Pakistanapseudes baruna was taken only at shallower stations off Brunei, between 6.5 and 20 m depth, at an average density of 2.2 individuals per m2 (at the stations where it occurred). Over all the material identified, the female:male sex ration was about 5:1.

Figures

FIGURE 10. Pakistanapseudes baruna sp. nov., female: A, holotype dorsal; B, proximal antennule articles; C, antenna; D, antenna of subadult male; E, labrum; F, left mandible; G, labium; H, maxillule; I, maxilla; J, maxilliped; K, maxilliped endite; L, epignath. Scale line = 1.0 mm for A, 0.2 mm for B to L.

FIGURE 11. Pakistanapseudes baruna sp. nov., female: A, cheliped; B to E, pereopods 1 to 4. Scale line = 0.25 mm.

FIGURE 12. Pakistanapseudes baruna sp. nov.: A, pereopod 5; B, pereopod 6; C, pleopod (plumose nature of all setae not shown, for clarity); D, uropod basis and exopod. Scale line = 0.25 mm for A and B, 0.2 mm for C and D.