Annexos abditospina, Błażewicz-Paszkowycz & Bamber, 2007

Błażewicz-Paszkowycz, M. & Bamber, R. N., 2007, New apseudomorph tanaidaceans (Crustacea: Peracarida: Tanaidacea) from eastern Australia: Apseudidae, Whiteleggiidae, Metapseudidae and Pagurapseudidae, Memoirs of Museum Victoria 64, pp. 107-148 : 111-116

Annexos abditospina sp. nov.

Figures 1–3

Material. Brooding female, holotype ( NMV J53137 ) Australia, Victoria, Eastern Bass Strait , 20 km SE of Port Albert (38°43.04'S, 144°18.02'E), 79 m, 18/11/1981, ( BSS 178 ), Wilson, RS et al .

Paratypes: 20 hermaphrodites ( NMV J55745 ), same locality as holotype; 1 specimen dissected on slides ( NMV J55945 ), same locality as holotype; VIMS Cruise 81-T-1, NZOI RV Tangaroa, Stn 178, 20 km SE of Port Albert, Victoria, 38°43.4'S 146°56.9'E, 26 m depth, 18 Nov 1981; coll. R. Wilson; 3 individuals ( NMV J55776 ), Tasmania, eastern Bass Strait , 20 km SSW of Babel I. (40°06.48'S, 148°24.18'E), 22 m, 14/11/1981 ( BSS 166 ), R.S. Wilson; 1 individual ( NMV J55777 ), Tasmania, central Bass Strait , 23 km E of Cape Rochon, Three Hummock I. (40°22.12'S, 145°17.00'E), 40 m, 03/11/1980, ( BSS 112 ), M.F. Gomon and G.C.B. Poore; 5 hermaphrodites ( NMV J55778 ), Victoria, eastern Bass Strait , 8 km S of South East Point, Wilsons Promontory (39°12.54'S, 146°27.18'E), 65 m, 18/11/1981, ( BSS 180 ), R.S. Wilson; 1 individual ( NMV J55779 ), eastern Bass Strait , 50 km SE of Port Albert (38°54.18'S, 147°13.24'E), 58 m, 18/11/1981, ( BSS 176 ), R.S. Wilson; 1 ovigerous female, 2 hermaphrodites, 5 individuals ( NMV J55780 ), eastern Bass Strait , 43 km SE of Port Albert (38°53.42'S, 147°06.30'E), 58 m, 18/11/1981, ( BSS 177 ), R.S. Wilson .

Description of female. Body dorsoventrally flattened, elongate, holotype 9.2 mm long (tip of rostrum to posterior of pleotelson), 6 times as long as wide, narrower posteriorly. Cephalothorax subrectangular, slightly longer than wide, anterior margin with conspicuous triangular, pointed rostrum with notches just anterior to ocular lobes. Eyes present; eyelobes rounded; no lateral spiniform apophyses anterior of branchial chambers. 6 free pereonites; pereonites 1 and 2 subequal in length, almost 1/3 as long as cephalothorax, lateral margins uniformly convex, dorsal sculpturing conspicuous; pereonites 3 to 6 with anterolateral spiniform apophyses and expanded posterolaterally at attachment of coxae; pereonite 3 as long as pereonite 2, pereonites 4, 5 and 6 subequal (5 longest), 1.3 times as long as pereonite 1 (all pereonites respectively 2.7, 2.4, 2.1, 1.7, 1.6 and 1.5 times as wide as long); conspicuous sickle-shaped ventral hyposphenium on pereonite 1, blunt hyposphenium with distal, posteriorlydirected spine, on pereonite 6. Pleon 1/3 as long as body, of 5 free subequal pleonites bearing pleopods; pleonites dorsally convex, more than 3 times as wide as long, laterally expanded by spiniform apophyses. Pleotelson rectangular, slender, 2.2 times as long as wide, with numerous plumose lateral setae.

Antennule peduncle 4-articled, proximal article 2.9 times as long as wide, internal margin finely corrugated, outer proximal penicillate setae, outer and inner tufts of simple setae at midlength and distally; article-2 0.3 times as long as article 1, with distal crown of inner and outer simple setae and dorsal penicillate setae; article 3 one-third as long as article 2, article 4 just shorter than article 3. Main flagellum of 19 segments; segments 11, 13 and 15 bearing aesthetascs; accessory flagellum of 6 articles.

Antenna proximal peduncle article without apophyses; article 2 inner margin finely denticulate, bearing elongate squama with 17 plumose marginal setae; peduncle article 3 as long as wide, with 1 seta; article 4 slightly shorter than article 5, and 3 times as long as article 3; article 5 with strong outer setae. Flagellum of 15 segments.

Mouth parts. Labrum not seen. Left mandible, bearing strong, crenulated pars incisive; lacinia mobilis with denticulate cutting edge, setiferous lobe with 4 bifurcate or trifurcate setae; pars molaris robust, blunt. Right mandible as left but without lacinia mobilis; outer margin denticulate; mandibular palp of 3 articles, article 1 just longer than wide with 7 inner setae, article 2 3.5 times as long as article 1 with group of longer and shorter simple inner setae in distal half; article 3 half length of article 2 with 10 inner simple setae increasing in length distally, 2 dorsal subdistal simple setae, and 2 longer distal setae. Maxillule inner endite with finely setose outer margin and blunt apophysis, inner margin proximally denticulate with adjacent setulose margin; 5 finely setulate distal setae, inner 3 distally compound; outer endite with 11 distal spines and 2 subdistal setae, outer margin finely setose, distally with microtrichia; palp of 2 articles, distally with 5 setae. Maxilla with serrations and setules on outer margin; outer lobe of outer endite with 2 setae with setules at midlength on outer margin, 8 distal setae, each distally setulose; inner lobe of movable endite with dense group of simple distal setae; outer lobe of inner endite with 6 simple, 3 trifurcate, 2 inner compound and 1 subdistal setulose spines; inner lobe of fixed endite with rostral row of numerous setae guarding 3 longer setae. Labium with distally-serrated outer margin and setulose distal margin, palp with fine lateral setules and 2 longer and 1 very-short distal setae. Maxilliped basis with inner and distal setae and inner-distal stout spine; palp article 1 with paired distal spines on outer margin and stout inner-distal spine; palp article 2 longer than wide, with rows of numerous short setae on inner margin, 2 longer proximal setae as long as article, outer margin with spine distally; palp article 3 wider than long, with numerous simple filtering setae along inner margin; palp article 4 with 5 distal setae, 1 outer subdistal seta and 5 inner distal setae. Endite with flagellate inner caudodistal seta, simple outer distal setae and stout, spatulate, distal spines; 5 coupling hooks. Epignath large, cup-shaped, distal spine setulose.

Cheliped slender. Basis 2.4 times as long as wide, dorsally naked, ventrally with 1 longer and 1 shorter proximal seta, midventral spine and tuft of 3 distal setae; exopodite absent. Merus elongate, narrower proximally, with midventral simple setae and ventrodistal group of 3 setae and short spine. Carpus 4.7 times as long as wide, with simple setae along ventral margin, dorsal and ventral distal setae much shorter. Chela fingers shorter than palm, ventral margin of fixed finger with 10 setae, longer seta at inner base of fixed finger; 6 setae near articulation of fixed finger; cutting edge of fixed finger with row of fine setules but no apophyses; dactylus with no apophyses on cutting edge, distal claw pointed.

Pereopod 1 with pronounced, setose spine-like apophysis on coxa. Basis stout, 3 times as long as wide, with sparse ventral setae, 3 distal setae around ventrodistal spine; inner proximal hook-like apophysis; exopodite absent. Ischium with 3 simple ventrodistal setae. Merus half as long as basis, with groups of ventral submarginal and dorsodistal setae, single ventrodistal spine but no dorsodistal spine. Carpus 0.8 times as long as merus, ventrally with 2 spines in distal half, and single dorsodistal spine. Propodus slightly shorter than carpus, with 4 ventral and 2 dorsal spines. Dactylus with mid-dorsal fine setae, no apparent ventral denticulations; unguis short.

Pereopod 2 more slender. Coxa with small spiniform apophysis. Basis 3.6 times as long as wide with 2 longer marginal, numerous ventral marginal and tuft of ventrodistal setae. Merus 0.8 times as long as carpus, with elongate ventral setae and slender ventrodistal spine. Carpus elongate, with rows of ventral and dorsodistal setae, and ventrodistal spine. Propodus 1.2 times as long as carpus, dorsal and ventral margins setose as figured, 2 ventral and 1 dorsodistal spines. Dactylus slender, unguis finely pointed, the 2 together 0.75 times as long as propodus.

Pereopod 3 similar to pereopod 2, but basis with penicillate seta, propodus with inner subdistal spine.

Pereopod 4 similar to pereopod 2 but basis stouter, 2.8 times as long as wide, without proximal hook-like apophysis, with dorsoproximal and ventrodistal penicillate setae, merus with midventral, ventrodistal and dorsodistal spines, carpus twice as long as merus, with midventral spines and distal crown of 4 spines about 0.5 as long as propodus, interspersed by longer setae; propodus with dorsodistal tuft of 2 short and 6 longer setae; dactylus plus unguis shorter than propodus but longer than longest dorsodistal propodal setae.

Pereopod 5 similar to pereopod 2, but without proximal hook-like apophysis, propodus with mid-dorsal penicillate seta and ventral row of 5 spines in distal half, dorsodistal setae as long as dactylus; dactylus and unguis slender, together as long as propodus.

Pereopod 6 basis with dorsal and ventral margins entirely setose, merus and carpus without spines, propodus with numerous ventral leaf-like propodal spines extending around distal margin of article.

Pleopods all alike. Basis elongate, with 4 ventral plumose setae, dorsal margin naked. Endopod longer than exopod; both rami slender, linguiform, with plumose setae.

Uropod biramous, both rami filiform, multi-segmented. Basis with 1 inner distal seta; exopod about 0.5 as long as endopod, with 13 segments; endopod elongate with 24 segments.

Male unknown.

Etymology. From the Latin abditus – hidden, secret, and spina – a thorn or spine, referring to the maxilliped palp inner spines and the proximal spiniform apophysis on the basis of pereopods 1 to 3 (noun in apposition).

Remarks. See above under generic remarks.