Monday, December 23, 2024

[Crustacea • 2024] Proasellus mikhaili • A New stygobiotic Species of the genus Proasellus Dudich, 1925 (Isopoda: Asellidae) from the Black Sea coast of the Caucasus, Russia


 Proasellus mikhaili Palatov & Chertoprud, 2024

Map of collection sites in the Black Sea coast of the Caucasus, general view and natural habitats of described species: A — habitus of P. mikhaili sp.n., paratype (♂); 6 — collection sites
C — photos of collection sites of P. mikhaili: 6a — spring stream (rheokrene) on Kadosh Cape, 3.5 km to NW of Tuapse town, ...; 6b — the Agoy River on the NE outskirts of Agoy village, ...


ABSTRACT 
A new stygobiotic species of water louses of the genus Proasellus Dudich, 1925 (Crustacea: Isopoda), P. mikhaili sp. n., is described from springs and groundwaters in the vicinity of the town of Tuapse on the Black Sea coast of the northwestern Caucasus, Russia. Representatives of this genus are reported for the first time from this coastal area. This new species is characterized by a number of unique features that immediately distinguish it from all known other Caucasian species of the genus. At present, this is the only species described from the region that has three connecting hooks in the retinacula of male pleopods I, as well as a shortened exopodite of pleopod V, significantly shorter than the endopodite in length. Among the diagnostic characters of this species are also a poor ornamentation of pereopods I–VII and a specific chetotaxis of the pleotelson represented by a dense covering of thin, hair-like setae. Probably, this species is an endemic of the Tuapsinsky District.

KEY WORDS: Crustacea, Asellidae, new species, stygobionts, crenobionts, local endemism, Transcaucasia.

Map of collection sites for Proasellus mikhaili sp. n. in the Black Sea coast of the Caucasus, general view and natural habitats of described species: 
A — habitus of P. mikhaili sp.n., paratype (♂);
B — map of collection sites for Proasellus in the Black Sea coast of the Caucasus. Numbers refer to: 1 — P. infirmus; 2 — P. linearis; 3 — P. ljovuschkini; 4 — P. similis; 5 — P. abini; 6 — P. mikhaili sp. n.;
C — photos of collection sites of P. mikhaili: 6a — spring stream (rheokrene) on Kadosh Cape, 3.5 km to NW of Tuapse town, 44°07ʹ37.55″N 39°02ʹ03.92″E; 6b — the Agoy River on the NE outskirts of Agoy village, 44°09ʹ05.1″N 39°02ʹ59.7″E.

Order Isopoda Latreille 1816 
Suborder Asellota Latreille, 1802 

Superfamily Aselloidea Latreille, 1802 
Family Asellidae Latreille, 1802 
Genus Proasellus Dudich, 1925 
 
Proasellus mikhaili sp. n.

DIAGNOSIS. Medium sized, depigmented species. Antenna I with six to seven flagellar articles, flagellum of antenna II with 42–55 articles. Inner plate of maxillula with five or six apical pappose setae. Propodus I elongate, oval, its inferior margin without a proximal apophysa, with two or three robust spiniform setae. Dactylus I with four or five short robust setae on inferior margin and ...

ETYMOLOGY. The species is named in honor of the renowned Russian hydrobiologist Mikhail Vitalievich Chertoprud (30.01.1975–23.02.2023), who spent many years studying aquatic invertebrates in the Krasnodar Territory and repeatedly conducted hydrobiological training courses at Cape Kadosh near Tuapse. 


Dmitry M. Palatov and Elizaveta M. Chertoprud. 2024. A New stygobiotic Species of the genus Proasellus Dudich, 1925 (Crustacea: Isopoda: Asellidae) from the Black Sea coast of the Caucasus, Russia. Invertebrate Zoology. 21(3); 369–383.