Piona harveyi, K & PešićK, 2025

Piona harveyi n. sp.

Zoobank: E060A5E4-DF46-4304-9464-FC872817157C

Figures 1-2 View Figure 1 View Figure 2

Material examined — Holotype male, New South Wales, Water Gardens, Batemans Bay , 35°42.733′ S 150°10.688′ E, 16 Dec. 2003, leg. H. Smit, dissected and slide mounted ( AMS) GoogleMaps . Paratypes: 7/12/0, same data as the holotype, one female dissected and slide mounted ( AMS), 7/11/0 (in fluid, RMNH).

Diagnosis — Male. Cx-IV partially fused medially, genital plates fused to Cx-IV, excretory pore fused to genital plate; anterior claw sensu ( Harvey 1996) of male III-leg with ventral clawlet; in both sexes P2 ventral margin convex, P4 slender, ventrally with two short setal tubercles and a subdistal peg-like seta. Genital field with 18-20 pairs of acetabula in male and 23—24 pairs of acetabula in female.

Description — Colour yellowish. Dorsum with one pair of relatively large, sickle-shaped platelets. Apodemes of Cx-I relatively short. Palp slender, P2 ventral margin convex, P4 slender, ventrally with two small setal tubercles, close to each other, flanked by some small setae, distal peg-like seta separated from setal tubercles ( Figure 1D View Figure 1 ). Legs long and slender.

Male. Cx-IV separated by a narrow cleft, fused posteriorly. Genital plates fused with each other, and, for about half of the anterior margin, to Cx-IV, with 18–20 pairs of acetabula. Gonopore short; excretory pore fused to genital plates ( Figure 1 View Figure 1 A-B).

III-L-6 about the half of length of III-L-5, slightly curved ( Figure 2D View Figure 2 ), setose, anterior claw (sensu Harvey 1996) strongly curved with ventral clawlet, posterior claw long and nearly straight ( Figure 2C View Figure 2 , inset). IV-L-4 modified with posterior concavity lined with several proximal and three distal peg-like setae ( Figure 2E View Figure 2 ).

Female Genital plates bowed, with 23-24 pairs of acetabula, two or three of these free in the membranous integument, and three of these on an anterior platelet ( Figure 1F View Figure 1 ). Palp as in male, but setal tubercles smaller ( Figure 2A View Figure 2 ).

Measurements. Male (holotype, in parentheses some measurements of paratypes). Idiosoma dorsally 813 (844—888, n=2) long and 600 (630–656, n=2) wide; dorsal platelet 64 long. Coxal field 619 long (measured from Cx-I tip to end of posterior extension of Cx-IV), Cx-III width 569. Genital field 291 wide between outer margins of acetabula; gonopore 53 long. Ejaculatory complex 155 long.

Palp: dorsal length/height: P1, 37/68; P2, 216/117; P3, 94/78; P4, 208/56; P5, 55/29. Gnathosoma ventrally 154 long, 203 with apodemes. Chelicera 254 long. Dorsal lengths of I-leg-1-6: 81, 118, 172, 227, 250, 246; dorsal lengths of II-leg-1-6: 85, 140, 191, 250, 266, 256; dorsal lengths of III-leg-1-6: 95, 141, 166, 234, 287, 138; dorsal lengths of IV-leg-1-6: 169, 41, 181, 258, 309, 253; swimming setae numbers are as follows: I-leg-4, 1; I-leg-5, 3; II-leg-4, 5; II-leg-5, 7; III-leg-4, 6; III-leg-5, 1; IV-leg-4, 3; IV-leg-4, 5.

Female. Idiosoma dorsally 1088 long and 825 wide. Coxal field 650 long, Cx-III width 666, medial length Cx-III+IV 188. Genital field 359 wide between outer margins of genital plates; gonopore 188 long, pregenital sclerite 100 wide. Egg (n=2) maximum diameter 152–156.

Palp: dorsal length/height: P1, 39/68; P2, 211/116; P3, 94/78; P4, 216/58; P5, 63/28. Gnathosoma ventrally 183 long. Chelicera basal segment 203 long, claw 75 long. Dorsal lengths of I-leg-1-6: 93, 119, 178, 241, 263, 263; dorsal lengths of II-leg-1-6: 88, 138, 208, 273, 284, 276; dorsal lengths of III-leg-1-6: 97, 144, 192, 263, 278, 256; dorsal lengths of IV-leg-1-6: 159, 153, 200, 281, 312, 241; swimming setae numbers are as follows: I-leg-4, 3; I-leg-5, 6; II-leg-4, 7; II-leg-5, 9; III-leg-4, 8; III-leg-5, 9; IV-leg-4, 6; IV-leg-4, 5.

Etymology — Named after Mark Harvey (Western Australian Museum) for his excellent contribution to the Australian Pionidae .

Remarks — Due to the similar structure of the genital field (genital plates fused for about half of the anterior margin to Cx-IV, excretory pore fused to genital plates) and anterior claw of III-leg with ventral clawlet, the male of the new species resembles Piona puripalpis K.O.

Viets, 1984, a species known from northern and eastern Australia ( Harvey 1996). The latter species differs in having slenderer and more elongated palpal segments (especially P2 and P4, see figures 99-100 in Harvey 1996). Two other Australian Piona species, i.e. P. australica , P. marchanti Harvey, 1996 and P. murleyi Harvey, 1996 have a more or less morphologically similar genital field, but differ in having much less acetabula (5-8 australica in and marchanti,

9-14 in murleyi), and in the males of these species Cx-IV is separated medially.

Distribution — New South Wales.