Exalloniscus burmaensis, Taiti & Cardoso, 2020

Exalloniscus burmaensis View in CoL n. sp.

Figures 17, 18, 22G

urn:lsid:zoobank.org:act:

Material examined

MYANMAR: Holotype: ♂ ( MZUF), Mon State, Saddan Sin Gu Cave , 16°31’43”N, 97°43’02”E, 26.XI.2015, leg. F. Brehier. GoogleMaps Paratypes: 1 ♂, 3 ♀♀ ( MZUF) , 3 ♀♀ ( MNHN), same data as holotype GoogleMaps .

Description

Maximum length: ♂ 3.5 mm; ♀ 3.8 mm. Body oval, flattened ( Figure 17A); colour grey-brown, with pale antennae and uropods ( Figure 22G). Dorsum covered with short triangular scale-setae ( Figure 17B). Cephalon ( Figure 17C,D) with lateral lobes triangular with rounded apices, slightly protruding laterally; frontal line straight, suprantennal line slightly bent down in middle; eyes consisting of 4-5 dark ommatidia. Pereonites with postero-lateral corners right-angled ( Figure 17E). Pleonites 3-5 with epimera falciform, directed backwards. Telson ( Figure 17F) triangular, wider than long, with concave sides and acute apex, surpassing posterior margins of uropod protopods. Antennula ( Figure 17G) third article with four superimposed and two apical aesthetascs. Antenna ( Figure 17H) fifth article of peduncle shorter than flagellum; flagellum diminishing in length from first to third, second flagellar article with one and third article with two aesthetascs. Buccal pieces as in E. schmalfussi n. sp., except for maxillula with entire teeth. Pereopods with dactylar seta flagelliform. Pereopod 1 carpus with transversal antennal grooming brush ( Figure 18B). Pereopod 7 ( Figure 18C) basis with distinct water conducting system. Uropod ( Figure 18A) exopod twice as long as endopod.

Male: Pereopod 1 ( Figure 18B) merus and carpus with some strong setae on sternal margin. Pereopod 7 ( Figure 18C) ischium with slightly convex sternal margin. Pleopod 1 ( Figure 18D) exopod triangular, as wide as long, outer margin almost straight, posterior point broadly rounded; endopod with distal part triangular, pointed, slightly directed outwards. Pleopod 2 exopod ( Figure 18E) triangular, longer than wide, with one subapical seta on outer margin; endopod with styliform distal part, longer than exopod. Pleopod 3-5 exopods ( Figure 18 FH) triangular, as long as wide, with two to four setae on outer margin.

Etymology The new species is named for Burma, former name of Myanmar.

RemarksExalloniscus burmaensis n. sp. is characterized by grey-brown coloration, eyes with 4- 5 dark ommatidia, male pleopod 1 exopod triangular with a widely rounded distal point and endopod with a pointed distal part slightly directed outwards. In the external characters the new species resembles E. papillosus from which it differs in the male pereopod 7 ischium without deep pit on rostral surface, male pleopod 1 exopod with wider distal point and almost straight outer margin, and endopod with distal part not twisted (compare fig. 5C,D in Taiti and Ferrara 1988).