Pseudopallene harrisi, 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 : 424-426

Pseudopallene harrisi sp. nov.

Figs. 2 G, 13A–F

Material examined: Holotype (P.90044): 1 female (SHE010), Nov-29 2009, Bass Point, New South Wales, 20 m depth, on bryozoans and hydroids. Paratypes ( S92225 ): 1 ovigerous male, 1 male (SHE010-1) from the same location.

Diagnosis: Large size, 50 mm in leg span, red body with dorsally chalky bright yellow lateral processes and cheliphore bases, legs with no constrictions, predominantly red, coxa 3 and distal sections of femur and both tibiae with same bright yellow colouration. Massive chelae, fingers short, stout; propodus with four large heel spines decreasing in size proximally. Sequence divergence from 10 to 14 % in COI and 6 to 23 % in ITS when compared to other congeneric species for which these DNA fragments were available.

Description of female: Leg span 50 mm. Body ( Fig. 13 A) smooth, glabrous, fully segmented, when alive coloured dark red with ocular tubercle, lateral processes, third coxae and pre-ocular surface at the base of cheliphores coloured bright yellow, also wide yellow bands distally on major leg articles ( Fig. 2 G); colouration disappears after ethanol preservation. In holotype, neck relatively long, with parallel sides, with round mid-dorsal mound, longitudinal cuticular division line arising from anterior margin, especially clear in frontal view ( Fig. 13 C). Ocular tubercle ( Fig. 13 A,C) as tall as wide, with dorsolateral papillae, slightly inclined backwards, four darkly pigmented eyes, posterior pair slightly larger. Lateral processes ( Fig. 13 A) almost twice as long as wide, well separated, at least by half their diameters. Abdomen horizontal, as long as fourth lateral processes.

Proboscis ( Fig. 13 B,C) conical, distally tapering to a narrow mouth, with dark marks on distal narrow portion seen after preservation.

Cheliphores ( Fig. 13 A-C) robust, scape and palm subequal in length, palm inflated giving massive globose appearance; fingers short, half length of palm, movable finger clearly curved, with mid-point lobe on thick, darker cutting edge; immovable finger longer than movable finger, also thick and dark on cutting margin; proximal gap seen when fingers closed.

Oviger ( Fig. 13 E,F) fifth article longest, curved, with distal, round apophysis; oviger compound spine formula 16:13:11:11 ( Fig.13 E); terminal claw slightly shorter than tenth article ( Fig.13 E), curved, with eight denticulations on distal half of ectal margin, at least 18 denticulations along endal margin and tip ( Fig. 13 F).

Legs ( Fig. 13 A,D) long, about 4.5 times the body length, slender, covered in tiny spinules from coxae to propodus, coxa 2 more than twice the length of coxa 1, tibia 2 longest article followed by femur and tibia 1. Tarsus short, typical, with ventral spines, largest surrounded by short, thick spines; propodus straight, inconspicuous heel, four heel spines, most distal largest, other three decreasing in size proximally; main claw longer than half of the propodus length.

Measurements of female holotype in mm: body length = 5.35; body width = 3.20; abdomen length = 0.76; ocular tubercle height = 0.39; proboscis length = 1.63; chela fingers = 0.95; scape = 1.62; oviger 5th article = 1.55, 10th article = 0.45, terminal claw = 0.25; 3rd leg coxa 1 = 0.79, coxa 2 = 1.91, coxa 3 = 1.0, femur = 5.45, tibia 1 = 5.24, tibia 2 = 6.85, tarsus = 0.35, propodus = 1.40, claw = 0.75.

Etymology: The species is named after Mick Harris, an experienced diver and pycnogonid enthusiast who contributed with the collecting and photography of these specimens and greatly supported the field logistics at Shellharbour in November 2009.

Remarks: Of all investigated species in this study, P. harrisi shows the closest resemblance to the P. ambigua holotype and the P. ambigua specimens deposited in Museum Victoria. This holds especially for the relative size and proportions of the chelae (compare Fig. 13 B, C and Fig. 16 A, B). However, the even larger overall body size and slightly more robust general appearance as well as the oviger configuration with more spines and denticulations on the terminal claw set P. h ar r is i aside from P. ambigua . Additionally, the very distinctive body colouration pattern of P. harrisi is significantly different from the reported predominantly yellow live colouration of P. ambigua (Staples 1997, 2007). Notably, Clark (1963) in his cautious description of putative P. ambigua material from the collection of the Australian Museum, Sydney, mentions similar red and yellow live colouration of a single medium-sized immature specimen from NSW. Detailed re-examination of the many Pseudopallene specimens collected along the New South Wales coast over the years may reveal that P. harrisi is represented in the Australian Museum collection.

In terms of size, the big and robust P. laevis (Hoek, 1881) , which has been described on the basis of a single female specimen from the Bass Street, is similar to P. ambigua and P. harrisi . However, since the location of the P. laevis holotype is currently unknown, its re-investigation was not possible. Due to this unfortunate circumstance and the different geographic location of both forms, we decided to set P. harrisi apart from P. l a e v i s.

Figures

FIGURE 2. Live colouration of some of the species of Pseudopallene and Stylopallene included in the study. A, fresh live bryozoans Orthoscuticella spp. with many Pseudopallene specimens; B, P. constricta sp. nov., male in ventral view with egg masses attached to the ovigers; C, P. ‘ variabilis’ - complex, frontal-ventral view, note black tips of proboscis and chela fingers; D, P. flava sp. nov. in its natural habitat; E, Close-up of P. brevicephala male characterized by uniform orange-red body and legs, bearing orange eggs and transparent post-embryonic stages; F, P. pachycheira attached to bryozoan, showing banding pattern and constrictions of long leg articles; G, P. h a r r i s i sp. nov. in its natural habitat showing red-and-yellow colouration; H, specimen from the P. ‘ variabilis’ - complex with yellow-and-red colouration attached to live bryozoan; I, Stylopallene cheilorhynchus showing characteristic live black-and-creamy-white banding, photograph taken in captivity. All specimens from Eaglehawk Neck, Tasmania except 2 G and 2 H collected at Bass point, New South Wales.

FIGURE 13. Pseudopallene harrisi sp. nov., A, B, female holotype (P. 90044); A, dorsal view showing only proximal portions of legs; B, detail of chelae, ventral view; C-F, male (S 92225); C, frontal view; D, propodus and terminal claw of third walking leg; E, distal oviger articles with compound spines and terminal claw; F, detail of denticulations of terminal oviger claw. Scale bars on stereomicroscopic images = 1 mm or as shown.

FIGURE 16. Pseudopallene ambigua Stock, 1956. Male specimen deposited at Museum Victoria (J 57280). A, frontal view; B, detail of chelae, ventral view. Scale bars = 1 mm.