Pseudopallene tasmania, Arango, Claudia P. & Brenneis, Georg, 2013

Arango, Claudia P. & Brenneis, Georg, 2013, New species of Australian Pseudopallene (Pycnogonida: Callipallenidae) based on live colouration, morphology and DNA, Zootaxa 3616 (5), pp. 401-436 : 417

Pseudopallene tasmania sp. nov.

Figs. 3 D, 7A–H

Material examined: Holotype (J4517): 1 female (PSE4a), Nov-2009, Eaglehawk Neck, Tasmania , 5–20m depth on Orthoscuticella spp. Paratypes ( S92216 ): 2 females (PSE4, 4b) from same location as holotype; ( S92217 ): 2 sub-adults (TAS21a, 35a), Jan-26 2007, Waterfall Bay at Eaglehawk Neck, 21 m depth, in kelp forest.

Diagnosis: Neck short, constricted; legs with no constrictions, femur thickest compared to distal segments, tibia 2 about 4 mm long, more slender than tibia 1; strigilis with very high number of compound spines, 68 in total, seventh article alone with 25 spines. Red-toned colouration of midgut when alive, losing colour after ethanol preservation. Sequence divergence from other Pseudopallene forms: 10 to 14 % in COI and 21 to 23 % in ITS.

Description of female: Leg span 38 mm; body ( Figs. 3 D; 7A) fully segmented, glabrous, holotype with encrusting epibionts on cuticle giving rough appearance dorsally; body and legs pale yellow, cuticle semitransparent, red-coloured midgut with its diverticula seen through cuticle when live, not visible after preservation. Neck ( Fig. 7 A,B) short, marked constriction, pre-ocular surface not divided, without mid-dorsal mound. Ocular tubercle ( Fig. 7 A,B) as tall as wide, with dorsal papillae, eyes darkly pigmented. Abdomen ( Fig. 7 A) as long as fourth lateral processes, not constricted distally or inflated, cleft anal opening. Lateral processes 1.5 times as long as wide, glabrous.

Proboscis ( Fig. 7 B,G,H) bullet-shaped, slightly inflated on distal section before tapering to mouth, no tuft of setae surrounding mouth.

Cheliphore ( Fig. 7 A,B,G) scape with constriction line proximally, not in male ( Fig. 7 H), as long as proboscis; chela palm inflated, fingers short, about half of palm length, with linear, smooth cutting-edge, movable finger slightly shorter than immovable finger, touching immovable finger just before its tip, fingers leaving proximal gap when closed, no setae on chelae.

Oviger fifth article longest, straight, compound spine formula: 25:18:15:10 ( Fig. 7 D), terminal claw margins not denticulated, only light crenulation on endal side ( Fig.7 C).

Legs ( Fig. 7 E,F,H) glabrous, with row of tiny, spare spinules dorsally and ventrally on major articles; third coxa twice as long as first; second coxa about three times as long as coxa 1; femur swollen compared to tibiae, subequal in length with tibia 2, eggs visible through cuticle; tarsus short, about 12 % of the propodus, one large tarsal spine aligned with heel spines on propodus; propodus straight, heel inconspicuous, four heel spines, two middle ones larger, eight sole spines; main claw nearly half the propodus length ( Fig.7 F).

Measurements of female holotype in mm: body length = 3.31; body width = 1.87; abdomen length = 0.45; ocular tubercle height = 0.38; proboscis length = 1.14; chela fingers = 0.63; scape = 1.42; oviger 5th article = 1.12, 10th article = 0.34, claw = 0.16; 3rd leg coxa 1 = 0.55, coxa 2 = 1.69, coxa 3 = 0.93, femur = 4.6, tibia 1 = 3.8, tibia 2 = 4.7, tarsus = 0.19, propodus = 1.23, claw = 0.51.

Etymology: Species named after the type locality. Tasmania seems to harbour highly diverse Pseudopallene assemblages yet to be described. Noun in apposition.

Remarks: When alive, these specimens were clearly distinct from other Pseudopallene specimens with their clear cuticle showing red midgut diverticula. This pattern of colouration has not been described before in the genus. Together with the high count of compound ovigeral spines (>60 spines) and the inconspicuous propodal heel, these are unusual characters that segregate this new species from other known Pseudopallene . According to the molecular data, the species is highly divergent with more 10 % variation in the COI and 23 % in the ITS sequences compared to other local Pseudopallene species ( Table 2 ).

Figures

FIGURE 3. Dorsal view of eight morphotypes of Pseudopallene collected at Eaglehawk Neck, Tasmania. A, P. flava sp. nov.; B, P. constricta sp. nov.; C, P. ‘ variabilis’ - complex; D, P. tasmania sp. nov.; E, P. reflexa; F, P. gracilis sp. nov.; G, P. brevicephala; H, P. pachycheira. Scale bars = 1 mm.

FIGURE 7. Pseudopallene tasmania sp. nov., holotype female (J 4517). A, dorsal view; B, frontal view showing the proximal constriction of the cheliphore scapes, characteristic of Pseudopallene females; C, terminal oviger claw, tip broken; D, distal articles of oviger; E, third leg; F, propodus and terminal claw of third walking leg; G, chelae and mouth. H, sub-adult (TAS 35 a), frontal view. Scale bars on stereomicroscopic images = 1 mm.