Tanystylum zuytdorpi, Arango, Claudia P., 2009

Arango, Claudia P., 2009, New species and new records of sea spiders (Arthropoda: Pycnogonida) from deep waters in Western Australia, Zootaxa 1977, pp. 1-20 : 17-18

Tanystylum zuytdorpi n. sp.

( Figures 7 , 8 D)

Holotype: WAM T92363, 1 male. 5 December 2005, Zuytdorp Wreck, Western Australia, CSIRO station 104- 0 11, collected with Sherman sled from 27.0517°S 113.1010°E to 27.0490°S 113.1000°E, hard bottom, 97 m.

Diagnosis: Trunk glabrous, lateral processes smooth. Abdomen tall, diagonal, nearly 80% of body length. Ocular tubercle bi-apical. Proboscis barrel-shaped. Chelifores as long as half proboscis length. Palps five-segmented, third segment long with distal constriction mark. Oviger with simple spines on strigilis. First coxae with three tubercles, anterior one prominent and bent; tarsus armed with setae; auxiliaries longer than half of main claw.

Description: Body of typical size for the genus, circular, not segmented, glabrous, granulose cuticle, lateral processes touching from base to distal margin, glabrous ( Fig. 7 A). Ocular tubercle tall, less than twice as high as its basal width, two apical cones, front one taller and more acute, with long, curved apical cone projecting forward; eyes darkly pigmented ( Fig. 7 B). Proboscis more than half length of trunk, barrel-shaped, narrow rim distally, no deep commissures ( Fig. 7 E). Abdomen tall, diagonal, arising from basal mound, armed with distal seta ( Fig. 7 B). Chelifores one-segmented, tapering distally, half as long proboscis, with mid-dorsal hump armed with one seta. Palps longer than proboscis, 5-segmented, third segment longest, anterior half inflated, constricted distally, fourth segment shorter than second, fifth segment long and curved upwards, with ventral setae ( Fig. 7 B). Oviger typical, 10-segmented, fifth segment longest, endal spine and male apophysis on seventh segment, two ectal spines on eighth, ninth and tenth with one and two distal simple spines respectively ( Fig. 7 F). Legs short, first coxae with three distal tubercles horizontally, the most anterior of these protuberances prominent, bent backwards, one fine seta on small tubercle at bend, another seta at tip ( Fig. 7 A); third coxae slightly longer than first; tibia 2 longest segment; femur longer than tibia 1, male cement gland short tube opening on dorsodistal tubercle; setae dorsally on femur and tibiae; tarsus small, armed with many setae ( Fig. 7 C); propodus almost four times longer, slightly curved, with three heel spines and seven sole spines; main claw nearly half length of propodus; auxiliary claws 0.6 times length of main claw ( Fig. 7 D).

Measurements of holotype (in mm): Trunk length = 1.03; trunk width (across second pair of lateral processes) = 1.10, proboscis = 0.69, abdomen = 0.84, palp segment 1 (p1) = 0.15, p2 = 0.12, p3 = 0.46, p4 = 0.11, p5 = 0.37; oviger segment 1 (o1) = 0.13, o2 = 0.18, o3 = 0.3, o4 = 0.3, o5 = 0.4, o6 = 0.17, o7 = 0.14, o8 = 0.08, o9 = 0.08, o10 = 0.03; coxa 1 = 0.23, coxa 2 = 0.4, coxa 3 = 0.33, femur = 1.01, tibia 1 = 0.92, tibia 2 = 1.07, tarsus = 0.15, propodus = 0.58, claw = 0.27, auxiliary claw = 0.18.

Etymology: The species name refers to the locality where the specimen was found. The area is known as Zuytdorp Cliffs, named after the Dutch East Indies Company (VOC) ship Zuytdorp, wrecked between Kilbarri and Shark Bay, WA.

Remarks: This specimen seems closely related to Tanystylum papuensis Child 1996 , a species so far endemic to Papua New Guinea ( Child 1996). They share the tubercles distally on the first coxae, two apical cones on the ocular tubercle, a tall abdomen and an apophysis on the 7th segment of the male oviger. Clear differences are the smooth lateral processes and cephalic segment without tubercles; the presence of five palp segments not six, the third segment longer with a constriction mark distally, and the lack of a strong tarsal spine. The strigilis spines are simple, not bifurcate. The proboscis shape is very different, not tapering. This Tanystylum species was found in deeper waters than its usually intertidal counterparts.

Figures

FIGURE 7. Tanystylum zuytdorpi n. sp., holotype. A. Dorsal view; scale = 0.5 mm. B. Lateral view. C. Third leg; scale bar = 1 mm. D. Distal leg segments. E. Proboscis. F. Oviger. Scale bars D and E = 0.1 mm.

FIGURE 8. A. Hedgpethia calva n. sp., dorsal view. B. Parapallene challengeri, female, laterodorsal view; right legs 2 – 4 missing. C. Paranymphon bifilarium n. sp., dorsal view. D. Tanystylum zuytdorpi n. sp, dorsal view, three legs missing.