Exalloniscus tridentatus Li & Jiang, 2024

Jiang, Chao, Yao, Chonghui, Huang, Luqi & Li, Weichun, 2024, Five new species of Exalloniscus Stebbing, 1911 (Crustacea, Isopoda, Oniscidea) from China, Zoosystematics and Evolution 100 (2), pp. 373-383 : 373

publication ID

https://dx.doi.org/10.3897/zse.100.115813

publication LSID

lsid:zoobank.org:pub:1B0AF998-E43A-4F82-9F97-F6F8C99133B4

persistent identifier

https://treatment.plazi.org/id/C7A742F7-5BCF-4A53-AA09-099FB4E8DDB3

taxon LSID

lsid:zoobank.org:act:C7A742F7-5BCF-4A53-AA09-099FB4E8DDB3

treatment provided by

Zoosystematics and Evolution by Pensoft

scientific name

Exalloniscus tridentatus Li & Jiang
status

sp. nov.

Exalloniscus tridentatus Li & Jiang sp. nov.

Figs 1F View Figure 1 , 6 View Figure 6

Type material.

Holotype. China: male, Shaanxi Province, Zhashui County, Dongshan Forestry Park (33°42'N, 109°01'E), alt. 1020 m, 12 May 2021, Chao Jiang leg., habitus no. ZS2301, prep. slide no. L23095 (JXAUM).

Paratypes. China: two males, two females, same data as the holotype, nos. 20210512007-20210512009 (CMMI).

Diagnosis.

Male pleopod 1 exopod straight on outer margin, and endopod bearing three well-developed dentations at apical part.

Description.

Maximum length: male 2.5 mm and female 2.8 mm.

Body oval, slightly convex. Colour white mixed with pale brown. Cephalon with lateral lobes slightly protruding laterally, apex rounded. Eyes with three ommatidia. Pereonites with postero-lateral corners directed backwards. Pleonites 3-5 with epimera falciform, protruding backwards. Telson triangular, twice as wide as long, lateral margin slightly concave, apex rounded. Uropod exopod approximately twice as long as endopod (Fig. 1F View Figure 1 ).

Antenna with fifth article of peduncle slightly longer than flagellum; ratio of flagellum approximately 3:2:2 (Fig. 6A View Figure 6 ).

Pereopod 1 with long strong setae on sternal margin of merus and carpus (Fig. 6B View Figure 6 ). Pereopod 7 with several strong setae on sternal margin; basis without water conducting system; ischium almost straight on sternal margin (Fig. 6C View Figure 6 ).

Male pleopod 1 exopod oval, straight on outer margin; endopod with apical portion bearing rounded hyaline lobe and three well-developed dentations (Fig. 6D View Figure 6 ). Pleopod 2 exopod triangular; endopod flagelliform, longer than exopod (Fig. 6E View Figure 6 ). Pleopods 3-5 nearly triangular with several setae on outer margin (Fig. 6F-H View Figure 6 ).

Etymology.

Latin: Exalloniscus tridentatus = trident. The new species name refers to the male pleopod 1 endopod with three dentations at apical portion.

Remarks.

This new species is similar to E. cortii Arcangeli, 1927 by body shape and male pleopod 1 endopod bearing a rounded hyaline lobe at the apical portion (Figs 1F View Figure 1 , 6D View Figure 6 versus Figs 1G View Figure 1 , 7D View Figure 7 ). But it can be distinguished by pereopod 7 basis without water conducting system, pleopod 1 exopod straight on the outer margin, and endopod bearing three well-developed dentations at the apical portion (Fig. 6C, D View Figure 6 ). In E. cortii , pereopod 7 basis has a well-developed water conducting system, pleopod 1 exopod is sinuous on the outer margin, and endopod with two spinelike projections at the apical apex (Fig. 7C, D View Figure 7 ).

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Isopoda

SubOrder

Oniscidea

Family

Oniscidae

Genus

Exalloniscus