Taxonomic study on the genus Mongoloniscus Verhoeff, 1930 (Isopoda, Agnaridae) from China: morphological and phylogenetic analyses Author Jiang, Chao 0000-0003-1841-1169 State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China Author Zhong, Jing State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China Author Wang, Zhidong State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China Author Li, Weichun 0000-0003-0154-861X College of Agronomy, Jiangxi Agricultural University, Nanchang 330045, China Author Huang, Luqi State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China text ZooKeys 2024 2024-05-23 1202 229 253 journal article 10.3897/zookeys.1202.113560 B493B7C6-9977-4A6C-B9D4-D4A865468DC8 Mongoloniscus parvus Jiang, Li & Huang sp. nov. Figs 4 E, F , 7 Type material. Holotype . China : ♂ ( 20200913004 ), Liaoning Province , Huanren Manchu Autonomous County : Erpengdianzi Town , Yaoqianshu Village ( 41.1893 ° N , 125.6383 ° E ), 610 m asl ., 13. ix. 2020 , coll. Chao Jiang . Paratypes . 3 ♂♂ , 2 ♀♀ ( 20200913003 , 2020091300005 ), same data as the holotype ; 3 ♂♂ , 2 ♀♀ ( 20200906002 – 20200906005 ), Liaoning Province , Huanren Manchu Autonomous County , Erpengdianzi Town ( 41.236 ° N , 125.6047 ° E ), 560 m asl., 6. ix. 2021 , coll. Chao Jiang . 1 ♂ , 2 ♀♀ ( 20200913001 , 20200913002 ), Jilin Province , Ji’an, Xihulugou Village ( 41.3348 ° N , 125.8893 ° E ), 670 m asl., 13. ix. 2020 , coll. Chao Jiang . Diagnosis. Antennal flagellum distal article approximately twice as long as the proximal article. Pereopod 7 ischium sternal margin fringed with sparse setae; carpus slightly expands on tergal margin. Pleopod 1 exopod oval, distal apex slightly concave, forming two inconspicuous lobes, inner lobe bearing one seta. Description. Body length of males 5–9 mm and females 4–9 mm . Body elongated and convex, ~ 2.3 × as long as widest pereonite. Dorsum distinctly granulated, brown-gray color with usual yellowish muscle spots. Numerous gland pores along entire margin pereonites margin (Fig. 4 E, F ). Pereonite 1 with rounded posterior margin and postero-lateral corners. Noduli laterales on pereonites 1–4 much farther from lateral margins than those on pereonites 5–7. Telson triangular, ~ 1.5 × as wide as long, lateral margins slightly concave near middle, posterior apex blunted; uropodal exopod 1.2–1.5 × as long as protopod; protopod with an incision on outer margin (Figs 3 F , 4 E , 7 B ). Cephalon with medial lobe arched, not surpassing lateral lobes in dorsal view. Eyes with 14 or 15 ommatidia. Antenna with fifth article of peduncle and flagellum nearly equal in length; flagellum with distal article twice as long as proximal one (Fig. 7 C ). Figure 7. Mongoloniscus parvus sp. nov. , holotype A cephalon, pereonites 1 and 2 in dorsal view B pleonites, telson and uropod in dorsal view C second antenna D pereopod 1 E pereopod 6 F pereopod 7 G pleopod 1 H pleopod 2 I – K pleopods 3–5 exopods. Scale bars: 1 mm. Pereopod 1 bearing a brush of long setae on its carpus and merus (Fig. 7 D ). Pereopod 7 ischium rostral surface with shallow depression; carpus slightly expands on tergal margin (Fig. 7 F ). Pleopods 1–5 exopods with monospiracular internal lungs (Fig. 7 G – K ). Male: pleopod 1 exopod oval, outer margin sinuous, distal apex slightly concave and forming two inconspicuous lobes, inner lobe bearing one seta near apex (Fig. 7 G ). Pleopod 2 exopod almost triangular, slightly concave on outer margin (Fig. 7 H ). Pleopod 1 endopod with broad basal part, narrowed towards apical apex, apex bearing several setae, bent outwards and ending with two pointed tips (Fig. 7 G ); pleopod 2 endopod longer than exopod, distal article thin and long (Fig. 7 H ). Etymology. Latin parvus = small. The new species name refers to the pleopod 1 with a small exopod. We suggest the Chinese common name as “ 小蒙潮虫 ”. Distribution. China ( Liaoning , Jilin ).