Arcitalitrus moonpar, R Peart, 2006

R Peart, 2006, The Amphipod Genus Arcitalitrus (Crustacea: Amphipoda: Talitridae) of New South Wales Forests, With Descriptions of Six New Species, Records of the Australian Museum 58, pp. 97-118 : 101-102

Arcitalitrus moonpar n.sp.

Figs. 3, 15 –17

Type material. HOLOTYPE, ♀, 9.0 mm, AM P60962, December 1999, M. Gray, G. Milledge and H. Smith . PARATYPES, 30 specimens AM P60963 . Paratypes are all from the type locality.

Type locality. Three km southwest of Mangrove Mountain (33°22'28"S 151°15'39"E), New South Wales .

Other material examined. New South Wales, Australia: end of Darkes Forest , Woronora Dam Catchment (34°12'51"S 150°54'E), 8 specimens, 8–22 December 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; junction of Urumbilum Creek road and Loudens road, Orara State Forest (30°19'35"S 152°55'00"E), 3 specimens, 9–23 December 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; end of Little North Arm road, west bank of Rosewood River , Dorrigo National Park (30°24'06"S 152°46'18"E), 35 specimens, 10–24 November 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; beside Hacking River , Lady Wakehurst Drive, Royal National Park (34°09'47"S 151°00'55"E), 40 specimens, 6–20 December 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; junction of Moonpar and Mills roads, Moonpar State Forest (30°14'36"S 152°37'32"E), 15 specimens, 9–23 December 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; 2 km south southwest of Bostobrick , Christophersons Mountain (30°17'45"S 152°37'04"E), 55 specimens, 9–23 November 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; nearly 0.3 km east of Artillery Hill , Sir Bertram Stevens Drive, Royal National Park (34°04'55"S 151°03'40"E), 1 specimen, 6–20 December 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith; Horseshoe road, 3.5 km southeast of Thora, Scotchman State Forest (30°26'25"S 152°47'30"E), 1 specimen, 10–24 November 1999, collected from pitfall traps, M. Gray, G. Milledge and H. Smith .

Description. Based on holotype female. Body shape normally laterally compressed. Cuticle calcification absent. Eye medium (1 ⁄ 5 – 1 ⁄ 3 head length). Antenna 2 longer than head and first 3 pereonites; peduncular articles narrow. Mandible left lacinia mobilis 4 dentate. Maxilliped outer plate distally acute/arcuate; palp dactylus present and distinct. Pereonite 1 sternite without papillose process. Gnathopod 1 not sexually dimorphic; simple; merus and carpus not expanded; propodus subrectangular; palm absent; dactylus longer than palm. Gnathopod 2 not sexually dimorphic; chelate; narrow; merus and carpus expanded posteriorly; propodus “mitten-like”; palm obtuse; smooth; dactylus shorter than palm. Pereopods 3–7 long (½ length of body); simplidactylate. Pereopod 4 carpus similar in length to pereopod 3 carpus, dactylus similar to pereopod 3 dactylus. Pereopod 7 posterodistal lobe present. Gill 2 lobate, not incised. Gills 3–5 lobate, smaller than gills 2 and 6. Gill 6 lobate, anterior and posterior margins smooth, apically incised. Oostegites long (length greater than 2× width), weakly setose, setae with simple smooth tips. Epimera 1 to 3 not convergent. Epimeron 2 longer than epimeron 3. Epimeron 3 posteroventral margin smooth, posteroventral corner rounded. Pleopod 1 well developed, biramous, rami shorter than peduncle; inner ramus with 6 articles; outer ramus with 5 articles, outer ramus with 1–5 articles. Pleopod 2 well developed, biramous, rami shorter than peduncle; inner ramus with 5 articles, inner ramus with 1–5 articles; outer ramus with 4 articles. Pleopod 3 reduced, uniramous, rami shorter than peduncle; inner ramus with 1 articles; outer ramus without articles. Uropod 1 not sexually dimorphic; peduncle with 4 robust setae on peduncle; inner ramus shorter than outer ramus, with 3 robust setae on the margins, with 4 apical robust setae; outer ramus without marginal robust setae, with 2 apical robust setae. Uropod 2 not sexually dimorphic; peduncle with 3 robust setae; inner ramus subequal in length to outer ramus, with 1 marginal robust seta, 5 apical robust setae; outer ramus without marginal robust setae, with 4 apical robust setae. Uropod 3 peduncle with 1 robust seta; ramus shorter than peduncle, ramus bud-like (broad), with 2 robust setae. Telson as broad as long, entire, with marginal and apical robust setae, with 3–5 robust setae per lobe.

Etymology. Named after Moonpar State Forest, within the range of Ar. moonpar and treated as a noun in apposition.

Habitat. Forest floor leaf-litter.

Remarks. Arcitalitrus moonpar is a member of the “Dorrieni” species group. It differs from the only other species in the group, Ar. dorrieni , in having weakly setose oostegites, a rounded posteroventral corner on epimeron 3, a reduced number of articles on the outer ramus of pleopod 1 and both rami of pleopod 2, a uniramous pleopod 3 and 8 (6 to 10) dorsal robust setae on the telson.

Distribution. New South Wales: southwest of Mangrove Mountain; on the shores of the Hacking River, Royal National Park; Woronora Dam Catchment; Orara State Forest; Dorrigo National Park; Moonpar State Forest; Christophersons Mountain; Scotchman State Forest.