Exalloniscus curvispinatus 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/1CFF7EBE-9FBA-46A3-857C-25511D27B65E

taxon LSID

lsid:zoobank.org:act:1CFF7EBE-9FBA-46A3-857C-25511D27B65E

treatment provided by

Zoosystematics and Evolution by Pensoft

scientific name

Exalloniscus curvispinatus Li & Jiang
status

sp. nov.

Exalloniscus curvispinatus Li & Jiang sp. nov.

Figs 1B, C View Figure 1 , 3 View Figure 3

Type material.

Holotype. China: male, Yunnan Province, Mengla County, Xiaomo Road (21°14'N, 101°42'E), alt. 650 m, 18 August 2023, Chao Jiang leg., habitus no. ML23002, prep. slide no. L23104 (JXAUM).

Paratypes. China, Yunnan Province: Two males, one female, same data as the holotype, no. 20230818301; one male, Menglian County, Nayunzhen (22°19'N, 99°35'E), 23 August 2023, Han Qiu leg., habitus no. NYZ23001, prep. slide no. L23105 (JXAUM); one male, Jinghong, Jinuo Village, Bakaxiaozhai (21°57'N, 101°12'E), 15 August 2023, Chao Jiang leg., no. 20230815301; three males, one female, Menglian County, Nayun Town, 23 August 2023, Han Qiu leg., nos. 20230302301 and 20230302202 (CMMI).

Diagnosis.

Male pleopod 1 exopod almost pentagonal, and endopod recurved outwards at apical part.

Description.

Maximum length: male 5.0 mm and female 4.2 mm.

Body oval, flattened and white. Cephalon with lateral lobes slightly protruding laterally, nearly triangular with blunted apex. Eyes absent. Pereonites with postero-lateral corner progressively more acute, directed backwards. Pleonites 3-5 with epimera falciform, protruding backwards. Telson triangular, twice as wide as long, lateral margin gently concave, ending with rounded apex. Uropod exopod as long as endopod (Fig. 1B View Figure 1 ).

Antenna with fifth article of peduncle slightly longer than flagellum; ratio of flagellum approximately 4:3:3 (Fig. 3A View Figure 3 ).

Pereopod 1 with long strong setae on sternal margin of merus and carpus, carpus with basal part as wide as apical part, bearing transversal antennal grooming brush (Fig. 3B View Figure 3 ). Pereopod 7 with several strong setae on sternal margin; basis with distinct water conducting system; ischium straight on sternal margin (Fig. 3C View Figure 3 ).

Male pleopod 1 exopod almost pentagonal; endopod with triangular lobe on outer margin, apical part thin and long, recurved outwards (Fig. 3D View Figure 3 ). Pleopod 2 exopod oval, apical part narrowed toward round apex; endopod flagelliform, longer than exopod (Fig. 2E View Figure 2 ). Pleopods 3-5 exopods oval with several setae on outer margin (Fig. 3F-H View Figure 3 ).

Etymology.

Latin: prefix curv - = curved plus spinatus = spinous. The new species name refers to the apical apex of male pleopod 1 endopod with a spinelike projection recurved outwards.

Remarks.

This species varied in body shapes (Fig. 1B View Figure 1 versus 1C). Specimens collected in Mengla (Fig. 1B View Figure 1 ) are distinctly thinner than the specimens found in Menglian (Fig. 1C View Figure 1 ).

The new species is similar to E. thailandensis in having a recurved pleopod 1 endopod (Fig. 3 View Figure 3 versus Fig. 4 View Figure 4 ). However, it can be distinguished by pereopod 1 with the basal part as wide as the apical part, pleopod 1 exopod almost pentagonal, and endopod without transversal sclerotized projections at the apical part (Fig. 3B, D View Figure 3 ). In E. thailandensis , the basal part of pereopod 1 is distinctly narrower than the apical part, pleopod 1 exopod is almost rounded, and endopod armed with transversal sclerotized projections at the apical part (Fig. 4B, D View Figure 4 ). Moreover, the body pigments of the new species (white, Fig. 1B, C View Figure 1 ) differ from E. thailandensis (brown, Fig. 1D View Figure 1 ) based on two male specimens from China, Yunnan Province, Mengla County, Guanlei Town, Baojiaoniu Cave. However, the colourless individuals of E. thailandensis have been described previously (see Taiti and Ferrara 1988). Thus, the body shape and colour should not be considered as exact characters to identify species of the genus.

Kingdom

Animalia

Phylum

Arthropoda

Class

Malacostraca

Order

Isopoda

Family

Oniscidae

Genus

Exalloniscus