Ligidium deltodontum Li, 2017, SP. NOV.
Creators: name: Li, Wei-Chun
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Ligiidae
Ligidium
Ligidium deltodontum

description: LIGIDIUM DELTODONTUM SP. NOV. (FIGS 2, 3)
Diagnosis
Unique in characters of the male pleopod 2 endopod: the subapical part has a thumb-shaped process on outer margin, and the apical tip has a triangular tooth-like process.
Description
Body length of males 8.0 mm, of females 9.0 – 10.0 mm. Body elongated (c. two times as long as wide); pereonites 1 and 2 without ‘bristle field’ on posterior margin of epimera. Colour in alcohol dark grey with white spots on dorsal surface.
Antennule (Fig. 2A): First article broadened towards three distal setae at the tip; second article about 1.5 times as long as the first, ending with three distal setae; third article with two small setae at apical tip.
Antenna (Fig. 2B): Third article of peduncle with seta near distal tip; fourth article bears three distal setae; fifth article equipped with two setae; flagellum composed of 13 articles.
Mandibles (Fig. 2C, D): Left mandible with three-toothed incisor; lacinia mobilis three-toothed; three penicils between lacinia mobilis and molar process. Right mandible with three-toothed incisor; lacinia mobilis single-toothed; two penicils between lacinia mobilis and molar process.
Maxillule (Fig. 2E): Inner lobe with three stout penicils and long seta near distal margin; outer lobe with six apical teeth.
Maxilla (Fig. 2F): Distally divided into two parts with blunted rounded apices; large lappet covered with tiny spines near distal margin and two elongated setose penicils near lateral margin at subapical part.
Maxilliped (Fig. 3A): Endite rectangular, distal margin with tooth at inner distal angle; palp with four setae on outer margin.
Telson (Fig. 3B): Distal margin distinctly convex in the middle, gently concave near lateral margin and forming blunted rounded corners.
Uropod (Fig. 3B): Uropodal protopod about three times as long as broad; inner-distal projection of protopod slightly longer than width of its base; endopod about twice as long as exopod, ending with long seta; exopodal tip with a cluster of small setae.
Male – pereopods (Fig. 3C, D): Pereopod 1 basis with three setae at both the inner and outer margins; ischium concave on outer margin, bears two small setae on inner margin; merus with seven setae on inner margin and two setae at outer distal angle; carpus with five setae on inner margin; propodus bears several small setae on inner margin and single small seta at outer distal tip. Pereopod 7 basis bears several tiny spines near base and single distal seta on inner margin; ischium narrow basally, broadened towards subtip, then narrowed towards distal tip, bears three setae on inner margin; merus with five long setae on inner margin and two setae at outer distal angle; carpus bears five long setae on inner margin and three setae at outer distal angle; propodus bears three small setae on inner margin.
Male – pleopods (Fig. 3E–I): Pleopod 1 exopod with rounded distal margin, endopod with triangular projection. Pleopod 2 exopod broad bean-shaped, distinctly concave at base; endopod long and thin; distal part thumb-shaped and concave on inner margin, outer margin with thumb-shaped process, apical tip with tooth-like process, pointing to base.
Holotype
Male: China, Jiangxi Province, Jingdezhen, Fuliang (29 ° 26 0 N, 117 ° 15 0 E), Huangzihao, c. 600 m a.s.l., 26.v.2012, W. Li leg. (= collector), DNA no. L14114 (Fig. 1).
Paratypes
One male and five females, same data as the holotype, DNA no. L14115 (Fig. 1).
Distribution and habitat
This species is only known from Jiangxi Province, China. The type locality is nearby a stream on the mountain slope in a secondary forest.
Etymology
From the Latin deltodontus (= triangular tooth-like), referring to the male endopod of pleopod 2 with a triangular process at apical tip.
description: Published as part of Li, Wei-Chun, 2017, Morphology and molecules reveal high species diversity of Ligidium (Crustacea: Oniscidea: Ligiidae) in Jiangxi, China, pp. 627-641 in Zoological Journal of the Linnean Society 179 (3) on pages 636-637, DOI: 10.1111/zoj.12464, http://zenodo.org/record/14806541