Pentachares sinensis Li & Guo 2022, gen. et sp. nov.
Creators: name: Li, Hai-Tao
name: Jin, Dao-Chao
name: Yi, Tian-Ci
name: Guo, Jian-Jun
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Trombidiformes
Limnocharidae
Pentachares
Pentachares sinensis

description: Pentachares sinensis Li & Guo gen. et sp. nov.
urn:lsid:zoobank.org:act: EAE7CCA4-5C4C-410E-B226-09B3FC6D913D
Figs 6–9
Diagnosis
Capitulum attached to a long tubular extension of integument; palp five-segmented, P-V attached to membranous protuberance at medioventral surface of P-IV, heavy seta and a pair of setae at distal end; dorsum without sclerites except for the frontal plate; on frontal plate, median eye invisible, rod-like O 1 and A 1 sitting at anterior part, A 2 at the middle of eye capsules, bifurcated O 2 near the middle of posterior part; 50–60 acetabula per side of genital field; excretory pore with a sclerotized ring; legs without swimming setae, claws simple.
Etymology
Named after the country where the specimen collected. “Sina-” means China.
Type material
Holotype CHINA • ♀; Guangdong Province, Xiangtoushan National Nature Reserve; 23°16′14″ N, 114°22′14″ E; 491 m a.s.l.; 24 Aug. 2019; Min Ao & Hai-Tao Li leg.; water depth 5–10 cm, located at the top of a hill, with organic detritus, dead wood and leaves on the bottom; GUGC, slide No. GD-LI-20190801.
Description
Female (n = 1)
BODY. Amber in color, lateral eyes red, gnathosoma invisible in dorsal view when alive (Fig. 6). Idiosoma extremely soft and extensible, integument papillate. Dorsum without sclerites in addition to frontal plate (Fig. 7A). Gnathosoma porous, in the ventral view rounded, rostrum relatively short; mouth disk with a loop of fine setae; porous basal segment of chelicera relatively large, proximal part of cheliceral stylet connected with basal segment vertically (Fig. 7B). Anterior part of frontal plate longer than eye capsule region; anterior margin concave, sclerotized inward; median eye invisible; O 1 rod-like and terminal expanded; A 2 at the middle of eye capsules; O 2 on the convex lateromedial plate and bifurcated; posterior part of frontal plate long, lateral margins covered by small tubercles densely; posterior margin straight; keel approximately as long as the frontal plate (Fig. 7C).
PALP. Five-segmented; P-I without seta; P-II with one dorsal and 3–4 ventral setae; a dorsodistal and 2 ventrolateral setae on P-III; P-IV with three ventral setae and one lateral heavy seta; P-V attached to a membranous protuberance at medioventral surface of P-IV, and bearing three setae at distal end (Fig. 8A–B).
COXAE. Cx-I inner-apical angles connected by a narrow bridge. Cx-I anterior margins concave, with uniformly stout setae. E 1 and E 2 on the membranous interspace between coxal groups. Cx-III triangular; Cx-IV elongated and triangular; all coxae porous (Fig. 8C).
GENITALIA. Genital field with 50–60 acetabula per side, acetabula inverted teardrop-shaped; gonopore with a slightly sclerotic plate with fine setae surrounded; a pair of elevated, longish sclerites with two apical setae behind gonopore; excretory pore with a sclerotized ring (Fig. 8C).
LEGS. With numerous stout setae except by the swimming setae, terminal segments of all legs with a loop of short setae; claws simple (Fig. 9A–D).
Male
Unknown.
Measurements
Idiosoma 2083 in length (with gnathosoma not extended), 1384 in width; protrusible membrane length 291 (flexibility maybe leading to inaccuracy); ACG length 368 (from anteromedial to posteromedial corner), PCG length 451 (from anteromedial to posteromedial corner); ocular plate 388 in length (from anteromedial to posteromedial corner), anterior part length 90, eye capsule region 49 in length, 114 in width, keel length 346; chelicera length 281; infracapitulum 154 in length (from the middle of infracapitulum furrow to rostrum); excretory pore length 71, sclerotic ring 81; dorsal lengths of palp segments: P-I 18, P-II 63, P-III 27, P-IV 39, P-V 33, P-IV heavy seta length 35, P-V apical seta length 23; dorsal lengths of leg segments: I-L-1 66, I-L-2 236, I-L-3 164, I-L-4 147, I-L-5 164, I-L-6 130. II- L-1 67, II-L-2 235, II-L-3 155, II-L-4 142, II-L-5 160, II-L-6 142. III-L-1 71, III-L-2 217, III-L-3 138, III-L-4 137, III-L-5 177, III-L-6 139. IV-L-1 62, IV-L-2 264, IV-L-3 184, IV-L-4 199, IV-L-5 218, IV- L-6 172.
Remarks
Pentachares sinensis Li & Guo gen. et sp. nov. with five-segmented palp is clearly distinguished from other species of the subfamily Rhyncholimnocharinae, but similar to Laterolimnochares huangshanensis Jin, 1999 and Limnochares spinosa Smit & Pesic, 2014. Pentachares sinensis Li & Guo gen. et sp. nov. differs from La. huangshanensis in the following aspects: 1) with a protrusible tube of soft integument in P. sinensis Li & Guo gen. et sp. nov., while without in La. huangshanensis; 2) body color amber in P. sinensis Li & Guo gen. et sp. nov., while pink in La. huangshanensis; 3) O 1 rod-shaped in P. sinensis Li & Guo gen. et sp. nov., while pectinate in La. huangshanensis; 4) terminal heavy seta of P-V smooth in P. sinensis Li & Guo gen. et sp. nov., while feathered in La. huangshanensis; and 5) the setae on coxae short in P. sinensis Li & Guo gen. et sp. nov., but long in La. huangshanensis. Pentachares sinensis Li & Guo gen. et sp. nov. differs from Li. spinosa: 1) with a protrusible tube of soft integument in P. sinensis Li & Guo gen. et sp. nov., while without in Li. spinosa; 2) O 1 and O 2 not smooth in P. sinensis Li & Guo gen. et sp. nov., but smooth in Li. spinosa; 3) terminal heavy seta of P-IV smooth in P. sinensis Li & Guo gen. et sp. nov., but feathered in Li. spinosa; and 4) the number of acetabula 50–60 in P. sinensis Li & Guo gen. et sp. nov., while only 40–50 in Li. spinosa.
description: Published as part of Li, Hai-Tao, Jin, Dao-Chao, Yi, Tian-Ci & Guo, Jian-Jun, 2022, Contributions to the knowledge of Eylaoidea (Acari: Hydrachnidiae) from China, pp. 53-70 in European Journal of Taxonomy 787 (1) on pages 61-66, DOI: 10.5852/ejt.2021.787.1613, http://zenodo.org/record/5817957