Pagurapseudes kimbla, Błażewicz-Paszkowycz & Bamber, 2012

Błażewicz-Paszkowycz, M. & Bamber, R. N., 2012, The Shallow-water Tanaidacea (Arthropoda: Malacostraca: Peracarida) of the Bass Strait, Victoria, Australia (other than the Tanaidae), Memoirs of Museum Victoria 69, pp. 1-235 : 69-74

Pagurapseudes kimbla sp. nov.

Figures 45–47

Material examined. 1 with oostegites (56368), holotype, Stn BSS185 , Western Bass Strait , 38º48.0'S 143º14.5'E, 47 m depth, 20 November 1981, hard rock, coll. R. S. Wilson; 1 juvenile (J56613), paratype, Stn BSS68 , Western Bass Strait, 39º27'S 142º55'E, 183 m depth, 10 October 1980, bryozoan mud, coll. G C B Poore ; 1 (J56370), paratype, Stn BSS171 , Eastern Bass Strait, 38º53.7'S 147º55.2'E, 71 m depth, 18 November 1981, medium sand, coll. R. S. Wilson ; 1 with oostegites (J55834), paratype, Stn BSS162 , Central Bass Strait, 40º09.2'S 147º31.9'E, 51 m depth, 14 November 1981, shelly sand, coll. R. S. Wilson ; 1 (J56369), paratype, Stn BSS203 , Central Bass Strait, 39º22.0'S 144º18.3'E, 60 m depth, 23 November 1981, coarse sand, coll. R. S. Wilson ; 1 subadult (J29171), paratype, Stn MSL EG88, Eastern Bass Strait, 37º52.65'S 148º42.15'E, 49 m depth, 4 June 1991, coarse sand, coll. N Coleman ; 1 (J29172), paratype, Stn MSL EG115, Eastern Bass Strait, 37º52.65'S 148º42.15'E, 49 m depth, February 1991, coarse sand, coll. N Coleman ; 1 brooding (J29173), paratype, Stn MSL EG111, Eastern Bass Strait, 37º52.65'S 148º42.15'E, 49 m depth, February 1991, coarse sand, coll. N Coleman ; 1 subadult (J51377), paratype, Stn VC 27 C1, Central Bass Strait, 36º23.92'S 145º18.43'E, 40 m depth, 11 May 1998, fine sand, coll. N Coleman.

Description of female. Body ( Fig. 45A) typical of a pagurapseudid, small, holotype about 1.7 mm long. Cephalothorax ( Fig. 45B) slightly rounded, just longer than wide, with convex anterior margin, rostrum a finely-denticulate semicircle; lateral carapace without denticulations, sparse, irregular plumose setae. Eyelobes rounded, eyes present as group of black-pigmented ocelli. Epistome not apparent. Pereonites 1and 3subequal, two-thirds as long as cephalothorax, pereonite 1 with paired anterolateral plumose or simple setae and single posterolateral simple setae; pereonite 2 shortest, 0.6 times as long as cephalothorax; pereonites 4 to 6 subequal, 0.9 times as long as cephalothorax; pereonite 5 longest, as long as cephalothorax. Pleon of five free subequal pleonites, each pleonite about half as long as cephalothorax. Pleonites 1, 2 and 3 only bearing pleopods. Pleotelson semicircular, 1.5 times as long as last pleonites, with plumose lateral seta on each side, paired longer and single shorter simple setae above uropod attachment, and two small posterior spines ( Fig. 47I).

Antennule ( Fig. 46A) proximal peduncle article 3.3 times as long as wide, with three larger and one smaller inner spine-like apophyses accompanied by plumose setae, no distal apophysis; outer margin with two proximal tooth-like apophyses and numerous penicillate and fewer plumose setae. Second peduncle article 0.35 times as long as first, with array of plumose and penicillate distal setae; third article 0.9 times as long as second, fourth article 0.4 times as long as third. Main flagellum of three segments, with single aesthetascs on each segment; accessory flagellum of two segments, distally not quite reaching distal edge of second segment of main flagellum.

Antenna ( Fig. 46B) with two basal articles fused into wide proximal peduncle article with complex inner denticulation, outer tooth-like apophysis and paired inner and single outer plumose setae; third article 1.3 times as long as wide with outer plumose seta; fourth peduncle article just longer than third, with two outer penicillate setae; fifth article twice as long as third with distal array of penicillate setae and one simple seta. Flagellum of two segments, distal segment with four distal setae.

Labrum ( Fig. 46C) bilobed, rounded, sparsely setose. Right mandible ( Fig. 46D) outer margin denticulate, with quadricuspid pars incisiva, setiferous lobe with four bifurcate setae, pars molaris ( Fig. 46 D') round, blunt, with marginal crenulations; palp ( Fig. 46D ") of three articles, proximal article with single long, plumose inner seta (broken on figure), second article longest, 1.8 times as long as proximal article, with four inner distally setulose setae in distal half; third article 0.8 times as long as second, with five progressively longer distally setulose setae in distal third, distal seta longer than article. Left mandible as right but with narrow, tricuspid lacinia mobilis (not figured). Labium ( Fig. 46G) outer margin denticulate, palp with two distal setae and setulose margins. Maxillule ( Fig. 46E) inner endite with four plumose distal setae (one broken on figure), outer apophysis and setulose margin; outer endite with 10 distal spines, outer margin finely setose; palp of two articles with distinct articulation, distally with four simple setae with rounded setulose tips. Maxilla ( Fig. 46F) moveable endite damaged in preparation; fixed endite outer lobe with four simple, one sabre-like, three trifurcate, one setulose and three bilaterally denticulate distal spines, inner lobe with two longer plumose setae and rostral row of 13 setae. Maxilliped ( Fig. 46H) basis with three outer plumose setae; proximal palp article with tridenticulate outer margin with one plumose seta, inner margin naked; second article with coarse denticulations along inner and outer margins, one long and one short plumose setae on outer margin, seven setulose setae and four plumose setae along inner margin; third article with bidenticulate outer margin, six inner marginal simple setae each with fine denticulation in distal half; distal article with seven inner-marginal and three distal setae, each with fine denticulation in distal half; endite ( Fig. 46 H') with naked outer margin, seven compound distal spines decreasing in size inwards and two subdistal plumose setae. Epignath ( Fig. 46I) large, inner lobes conspicuous, distal spine with setae surrounding tip.

Chelipeds ( Fig. 47A) showing no conspicuous dimorphism. Compact basis 1.6 times as long as wide, with three dorsoproximal setae, ventroproximal penicillate seta, mid-ventral spine and ventrodistal seta, ventrodistal margin densely setulose; exopodite absent. Merus quadrangular, two ventral simple setae and two tooth-like apophyses on ventrodistal margin. Carpus elongate, twice as long as wide, widening distally, with sparse dorsal and ventral fine setae and two tooth-like apophyses on mid-ventral margin. Propodus robust, as long as wide, fixed finger with three ventral, three distal and three dorsal setae, row of small rounded teeth along cutting edge; moveable finger stout, curved, with two distal setae.

Pereopod 1 ( Fig. 47B) longest pereopod, with basis slender, 4.7 times as long as wide, dorsal margin bearing five plumose setae interspersed amongst six triangular tooth-like apophyses, ventral margin with two spines in distal half and distal simple seta; exopodite present, large, distal article with thirteen plumose setae. Ischium one-quarter as long as basis, with naked dorsal margin, three ventrodistal plumose setae. Merus 0.6 times as long as basis, with two simple dorsodistal setae, ventral margin with nine plumose setae and two subdistal spines. Carpus shorter than merus, with one ventral simple and two ventrodistal plumose setae and three ventral spines. Propodus 1.3 times as long as carpus, with four slender ventral spines. Dactylus curved, as long as propodus, with fine ventral setae, unguis slender, sharp, 0.4 times as long as dactylus.

Pereopods 2 to 6 similar to each other, each about one-half to one-third as long as pereopod 1. Pereopod 2 ( Fig. 47C) basis stout, twice as long as wide, with plumose ventrodistal seta; ischium with paired ventrodistal setae. Merus, carpus and propodus bearing “sucker-like” spines, generally in two ventral rows, and plumose setae as figured. Merus 1.2 times as long as carpus; propodus 1.1 times as long as carpus, without distal spine; dactylus and unguis not fused, with minute inner seta. Pereopod 3 ( Fig. 47D) similar but carpus as long as propodus. Pereopod 4 ( Fig. 47E) slightly more compact, basis 1.7 times as long as wide, fewer “sucker-like” spines on merus, carpus longer than merus or propodus. Pereopod 5 ( Fig. 47F) as pereopod 4. Pereopod 6 ( Fig. 47G) propodus with dorsodistal denticulate spine.

Pleopods ( Fig. 47H) only present on pleonites 1, 2 and 3, biramous, reduced; basis naked; exopod with outer proximal and three distal plumose setae, endopod with four distal plumose setae. Uropod ( Fig. 47I) biramous, basis with two plumose distal setae; endopod longer than basis, of three segments, first distally naked, second segment as long as first with simple distal seta, third segment with three distal setae and one penicillate seta; exopod of one segment, subequal in length to proximal endopod segment, with two distal setae.

Male. Unknown.

Etymology. The HMAS Kimbla was one of the vessels used on the Bass Strait Survey between 1979 and 1984 (noun in apposition).

Remarks. Pagurapseudes kimbla sp. nov. is the only species of the genus to have two segments in the accessory flagellum and three in the main flagellum of the antennule. Equally, no previously described species of the related genus Macrolabrum has this combination of antennular flagellar segments. The present species is also unusual in having the propodus of pereopod 2 longer than the carpus (in other species it is conspicuouslyshorter).Theonlyotherspeciesof Pagurapseudes to have only two segments in the antennular accessory flagellum are P. inquilinus Bamber (2007) from 440–450 m depth off New Caledonia, which has seven segments in the main flagellum ( Bamber, 2007), and P. victoriae (see above) which has 5 or 6 segments in the main flagellum. Both of those species have one dorsal and one ventral seta on the pleopod basis, whereas P. kimbla has none.

Pagurapseudes kimbla was taken only occasionally, from throughout the Bass Strait at depths from 40 to 183 m, and on varied substrata.