Mongoloniscus crenatus Jiang, Li & Huang 2024, sp. nov.
Creators: name: Jiang, Chao
name: Zhong, Jing
name: Wang, Zhidong
name: Li, Weichun
name: Huang, Luqi
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Agnaridae
Mongoloniscus
Mongoloniscus crenatus

description: Mongoloniscus crenatus Jiang, Li & Huang sp. nov.
Figs 4 A, B, 5, 6
Type material.
Holotype. China: ♂ (20210417001), Sichuan Province, Baoxing County, Muping Town, Lengmugou Provincial Geological Park (30.3699 ° N, 102.8125 ° E), 1020 m asl., 14. iv. 2021, coll. Chao Jiang.
Paratypes. China: 3 ♂♂, 8 ♀♀ (20210417002 – 20210417012), same data as the holotype. 4 ♂♂, 6 ♀♀ (20210412063 – 20210412066), Hubei Province, Yichang, Xiaoxita Forestry Park (30.7853 ° N, 111.3180 ° E), 100 m asl., 12. iv. 2021, coll. Zhidong Wang & Tianyun Chen. 1 ♂ (20210512006), Shaanxi Province, Zhashui County, Lengbinggou Village (33.6931 ° N, 109.0239 ° E), 1020 m asl., 12. x. 2021, coll. Chao Jiang. 3 ♂♂, 1 ♀ (20210417016 – 20210417019), Sichuan Province, Baoxing County, Dengchigou (30.5341 ° N, 102.9410 ° E), 1810 m asl., 17. iv. 2021, coll. Chao Jiang; 3 ♂♂, 1 ♀ (20210416040 – 20210416043), Qionglai, Datong Village, Dalong Road (30.5042 ° N, 103.3063 ° E), 770 m als., 14. iv. 2021, coll. Chao Jiang; 5 ♂♂, 24 ♀♀ (120220827008 – 20220827025), Hanyuan County, Fuling Town, Hanyuan Service Area (29.4370 ° N, 102.6343 ° E), 1080 m asl., 27. viii. 2022, coll. Chao Jiang; 6 ♂♂, 9 ♀♀ (20220828036 – 20220828048), Tianquan County, Binhe Park (30.0584 ° N, 102.7597 ° E), 760 m asl., 28. viii. 2022, coll. Chao Jiang; 18 ♂♂, 23 ♀♀ (20220829013 – 20220829028), Wenchuan County, Yingxiu Town (31.0557 ° N, 103.4887 ° E), 880 m asl., 29. viii. 2022, coll. Chao Jiang.
Diagnosis.
Cephalon with median lobe convex, medially with a small incision. Antennal flagellum with distal article twice as long as proximal article. Noduli laterales almost at same distance from the lateral margins. Pereopod 6 basis and pereopod 7 ischium fringed with long setae. Pleopod 1 exopod deeply bilobed at apex, inner lobe much longer than outer lobe; apex of male pleopod 1 endopod bent outwards and pointed.
Description.
Body length of males 7–9 mm and females 8–11 mm. Body elongated and convex, ~ 2–2.5 × as long as widest pereonite. Dorsum distinctly granulated, brown-gray color with usual yellowish muscle spots. Numerous gland pores along entire pereonite margin. Pereonite 1 with rounded postero-lateral corner, posterior margin nearly straight. Noduli laterales almost at the same distance from lateral margins (Fig. 4 A, B). Telson triangular, approximately twice as wide as long, lateral margins slightly concave at distal one third, posterior apex blunted; uropodal exopod ~ 2–2.5 and 1.5–2 × as long as protopod in males and females, respectively; protopod with an incision on outer margin (Figs 4 A, B, 5 B).
Cephalon with rounded lateral lobe no evidence surpasses eyes, median lobe convex, medially with a small incision (Fig. 5 A). Eyes with 15–19 ommatidia. Antenna with fifth article of peduncle longer than flagellum; flagellum with distal article 1.6–2.1 × as long as proximal one (Fig. 5 C).
Pereopod 1 bearing brush of long setae on its carpus and merus (Fig. 5 D). Pereopod 6 basis fringed with long setae and a distal protrusion on sternal margin (Fig. 5 E). Pereopod 7 ischium with sternal margin slightly concave and fringed with setae, rostral surface with shallow depression; carpus slightly expanded on the tergal margin (Fig. 5 F).
Pleopods 1–5 exopods with monospiracular internal lungs (Fig. 5 G – K). Male: pleopod 1 exopod oval, with robust sinuous outer margin; apex deeply bilobed and bearing several setae, inner lobe much longer than outer lobe (Fig. 5 G). Pleopod 2 exopod nearly triangular, bearing one line of setae on the outer margin (Fig. 4 H). Pleopod 1 endopod with broad basal part, narrowed towards apex, apex bent outwards and pointed (Fig. 5 G); pleopod 2 endopod longer than exopod, distal article thin and long (Fig. 5 H).
Remarks.
The new species resembles M. koreanus in morphology. It can be distinguished from the latter by the cephalon median lobe medially with a small incision, pereopod 7 with an unexpanded carpus on the tergal margin, and pleopod 1 endopod with a pointed distal apex. In M. koreanus, the cephalon median lobe is medially continuous, pereopod 7 has an expanded carpus on the tergal margin, and the distal apex of the pleopod 1 endopod is blunted. Furthermore, this species and M. koreanus formed two clades with high support in the phylogenetic analysis (Fig. 2), and their interspecific distances were much higher than their intraspecies distances (Suppl. material 1: table S 2).
Etymology.
Latin crenatus = notched. The new species name refers to the anterior margin of the cephalon with a small notch in the middle. We suggest the Chinese common name as “ 刻痕蒙潮虫 ”.
Distribution.
China (Hubei, Shaanxi, Sichuan).
description: Published as part of Jiang, Chao, Zhong, Jing, Wang, Zhidong, Li, Weichun & Huang, Luqi, 2024, Taxonomic study on the genus Mongoloniscus Verhoeff, 1930 (Isopoda, Agnaridae) from China: morphological and phylogenetic analyses, pp. 229-253 in ZooKeys 1202 on pages 229-253, DOI: 10.3897/zookeys.1202.113560