Pseudopallene brevicephala Staples, 2008

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 : 418

Pseudopallene brevicephala Staples, 2008

Figs. 2 E, 3G, 9A–D

Material examined: (S922219) 1 sub-adult (TAS28), 26 Jan 2007, Fortescue Bay, 21 m depth in kelp forest; 1 female (PSE7), 1 male (PSE7a), 2 sub-adults (PSE7b, PSE12), ( S92221 ) 2 post-embryonic stages (PSE12a, b) (no DNA available), Nov-26 2009, Patterson Arch, Eaglehawk Neck, 10–15 m depth, on Orthoscuticella spp; 3 postembryonic stages (PSE9, PSE9a, b), Nov-22 2009, Boulder Point, 5–10 m depth.

Remarks: The adult morphology of the Tasmanian specimens corresponds to the species description based on material from South Australia (Staples 2008), especially the diagnostic short neck ( Fig. 9 A), the distinct longitudinal cuticular division line on the cephalon ( Fig. 9 B), the oviger compound spine count (8:7:6: 6 in specimen PSE7) ( Fig. 9 C) and the propodus configuration ( Fig. 9 D). One character to add to the description of the species is the uniform red-orange colour on body and legs in live adults, sub-adults and post-embryonic stages at least for the Tasmanian specimens ( Fig. 2 E). Clark (1963) described P. dubia based on material from Port Arthur, Tasmania , with different types of chela shapes. Some specimens had a characteristic delicately-curved tube-like elongation of the movable finger, whereas others were lacking this feature. Staples (2005) already proved the P. dubia specimens to represent late developmental stages of Pseudopallene rather than fully grown adults, without assigning them to a species. So far, post-embryonic stages of different Pseudopallene species have been shown to exhibit the tube-like projection of the movable chela finger, e.g., in P. watsonae Staples, 2005 or in P. constricta sp. nov. (see below, see also Brenneis et al. 2011b). A detailed morphological description of our genetically identified orange-red post-embryonic stages of P. brevicephala from Tasmanian is still underway. However, first observations have shown that the movable chela finger of these individuals lacks the distal tube-like extension, similar to some of the specimens investigated by Clark (1963). This strongly indicates that (1) Clark confounded developmental stages of different species, his material probably including P. brevicephala besides other congeners and that (2) those post-embryonic stages having been cautiously assigned to P. brevicephala by Staples (2008) might in fact belong to another species, since they exhibit the distinctive tube-like elongation of the movable chela finger. This is the first record of P. brevicephala from Tasmania .

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 9. Pseudopallene brevicephala Staples, 2008. A, B, female (S 92219); A, body in dorsal-lateral view showing the diagnostic short neck; B, frontal-ventral view of cheliphores, proboscis and cephalic margin; C, D, male (S 92219). C, distal articles of the oviger, strigilis, terminal claw and distal apophysis of fifth article; D, propodus and terminal claw of third walking leg. Scale bars on stereomicroscopic images = 1 mm.