Niphargus lotharingiensis Weber & Brad, 2025

Niphargus lotharingiensis Weber & Brad sp. nov.

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Figs 48–56 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig

Diagnosis

Medium-sized Niphargus species, poorly setose. Right postero-ventral angle of epimeral plates. Six spines of maxilla I outer lobe with 1 tooth each; 1 spine with several smaller teeth. Mandibular palp with small number (1–2) of B setae. Gnathopods with 3 setae along outer margin of dactylopodite. Pereiopod VII, the longest leg, almost three quarters of total body length. Pleopods retinaculum with 3–4 hooks. Uropod I, longer exopodite. Uropod II, longer endopodite. Uropod III sexually dimorphic, exopodite elongated in males. Telson with 5 apical spines on each lobe. No pure diagnostic sites present in COI marker. A single 28S rDNA allele is diagnostic as well as 19 COI barcodes.

Etymology

The species name derives from the Latin name of Lorraine ( Lotharingia), where the type locality is situated. In Weber et al. (2023), this species was treated as N. schellenbergi R, R*.

Material examined

Holotype

FRANCE • ♂; Tunnel du Col des Croix (connecting Vosges and Haute-Saône); 47.8632° N, 6.7464° E; 16 Apr. 2018; Dieter Weber leg.; kept intact in 96% ethanol; 180416-17; MNHNL130585 . GoogleMaps

Paratypes

FRANCE • 1 ♂; same collection data as for holotype; 3 Jul. 2016; dissected and appendages drawn; 160703-02; ISER microscope slide DW160703-02 GoogleMaps • 1 ♀; same collection data as for preceding; dissected and appendages drawn; 160703-01; ISER microscope slide DW160703-01 GoogleMaps • 1 ♂; same collection data as for holotype; 3 Jul. 2016; ISER DW160703-11 GoogleMaps • 1 ♀; same collection data as for holotype; 3 Jul. 2016; ISER DW160703-07 GoogleMaps • 1 ♀; same collection data as for holotype; 3 Jul. 2016; ISER DW160703-03 GoogleMaps • 1 ♂; same collection data as for holotype; 3 Jul. 2016; 160703-09; MNHNL130586 GoogleMaps • 1 ♀; same collection data as for holotype; 3 Jul. 2016; 160703-01; MNHNL130587 GoogleMaps .

Molecular data

COI and 28S rDNA sequences of specimens belonging to Niphargus lotharingiensis sp. nov. were deposited in GenBank. COI and 28S rRNA accession numbers are present in Supp. file 6 and Supp. file 9, respectively.

Description (male DW160703-02)

Measurements

Total body length is 7.80 mm ( Fig. 48 View Fig ).

Head

Head ( Fig. 48 View Fig ) 7.5% of total body length. Eyes and rostrum absent.

Antennae

Antenna I ( Fig. 49A View Fig ): with main flagellum formed of 16 articles, representing 60% of total body length. Peduncle length in 43% of total length of antenna I. Accessory flagellum ( Fig. 49B View Fig ) biarticulated; proximal article slightly longer than first article of main flagellum; distal article 15% of total length of accessory flagellum, with 2 apical setae of different lengths and one aesthetasc. Aesthetascs ¼ of respective main flagellum articles ( Fig. 49C View Fig ).

Antenna II ( Fig. 49D View Fig ): flagellum formed of 10 articles and representing 60% of total length of antenna II. Most flagellum articles bear one aesthetasc, half the length of respective flagellum articles.

Mouthparts

Labrum ( Fig. 50A View Fig ): typical, subovoid shape, with 2 rows of fine setae located, 1 apical and 1 subapical. Labium ( Fig. 50B View Fig ). Large inner lobes with 1 row of fine setae on inner sides. Outer lobes with 1 row of fine setae subapically on inner sides.

Maxilla I ( Fig. 50C View Fig ): with 4 apical setae on distal article of palp. 6 spines of outer lobe with 1 tooth each and 1 spine with several small teeth. Inner lobe with 1 apical seta and several smaller, subapical setae.

Maxilla II ( Fig. 50D View Fig ): with inner lobe slightly shorter than outer lobe. 1 apical row of setae and 1 subapical seta on outer lobe. Row of small setae on outer margin of outer lobe.

Left mandible ( Fig. 50E View Fig ): 4 teeth on incisor process. 3 teeth on lacinia mobilis. 14 serrated setae, and 6 setae, between lacinia mobilis and molar process.

Right mandible ( Fig. 50F View Fig ): 4 teeth on incisor process. 6 teeth on lacinia mobilis. 9 serrated setae between lacinia mobilis and molar process. Long seta on molar process.

Mandibular palps ( Fig. 50E–F View Fig ): highly similar and of same length. 3 articles account for 21% (article 1), 38% (article 2) and 41% (article 3) of total length of palp. Proximal article without setae, median article with 9–11 ventral setae. Distal article of palp with one group of 4A setae, 4 groups with 1–2 B setae, 17–22 D setae and 7 E setae.

Maxilliped ( Fig. 51A View Fig ): with palp formed of 4 articles. Article 1 asetose. Article 2 with 31 setae aligned along inner margin. Article 3 with 6 apical setae, one group of 6 dorsal setae and one group of 9 setae on inner margin. Article 4 with 1 seta located on outer margin and 2 setae at nail insertion. Outer lobe with 4 apical setae and 15 flattened setae on inner margin. Inner lobe provided apically with 3 setae, 1 flattened seta and 2 plumose setae.

Gnathopods

Gnathopod I ( Fig. 51B View Fig ): coxal plate in shape of rectangular, with depth larger than width (ratio depth: width 1.0: 0.8). Basis length: width ratio 1.0: 0.41. Ischiopodite with one posteroventral group of 5 setae. Basis: carpus length ratio 1.0: 0.56. Carpus with row of 14 setae of various lengths along ventral margin, group of 7 setae located anterodorsally and one group of 5 setae on carpus surface close to ventral margin. Propodite nearly as long as wide, seven groups of 2–5 setae on ventral margin, one group of 6 setae on dorsal margin, one group of 3 setae on propodite surface close to dorsal margin, one group of 5 anteroapical setae, 3 mesial setae on lateral surface, 2 setae on lateral surface close to ventral margin and one group of 4 setae close to palmar corner. One strong palmar spine, one supporting spine and two denticulate spines present in palmar corner. Dactylopodite with claw 26% of total dactylopodite length and 3 setae along outer margin.

Gnathopod II ( Fig. 51C View Fig ): slightly larger than gnathopod I, with coxal plate in th shape of rectangular trapezoid; coxal plate width equal to its depth (ratio width: depth 1.0: 1.0). Ovoid gill and of same length as basis. Basis length:width ratio 1.0:0.27. Ischiopodite with one posteroventral group of 3 setae. Basis: carpus length ratio 1.0:0.54. Carpus with row of 12 setae of various lengths along ventral margin, group of 4 setae located anterodorsally and 1 row of 10 setae on carpus surface close to ventral margin. Propodite as long as wide, with 8 groups of 1–5 setae on ventral margin, 5 setae on dorsal margin, 3 mesial setae on lateral surface, 1 seta on lateral surface close to dorsal margin, 6 anteroapical setae and 4 setae close to palmar corner. 1 strong palmar spine, 1 supporting spine and 2 denticulate spines present in palmar corner. Dactylopodite with claw 33% of total dactylopodite length and 3 setae along outer margin.

Pereopods

Pereopod III ( Fig. 52A View Fig ): coxal plate in shape of rectangular trapezoid, as deep as wide. Propodite:dactylus length ratio 1.0: 0.44. Dactylus, with nail measuring half of total length of dactylus, 1 dorsal seta with plumose tip, and 1 seta at nail base. Pereopod III slightly longer than pereopod IV (pereopod III: pereopod IV length ratio 1.0: 0.92).

Pereopod IV ( Fig. 52B View Fig ): relatively rectangular coxal plate, with concavity on posterior margin, width: depth ratio 1.0: 0.94. Propodite length:dactylus length ratio 1.0: 0.4. Robust dactylus, with nail measuring half of total length of dactylus; 1 dorsal seta with plumose tip and 2 setae of different lengths at nail base.

Pereopod V ( Fig. 53A View Fig ): coxal plate of irregular shape, with deep concavity on ventral side, 6 anterior setae and 2 posterior setae. Basis ovoid-rectangular shaped, length: width ratio 1.0:0.62, 5 groups of 1–2 setae on anterior margin, 12 setae on posterior margin, 4 anteroapical setae of different lengths. Dactylus with 1 dorsal seta with plumose tip, 2 setae of different lengths at nail base, which represents 40% of total dactylus length. Propodite length: dactylus length ratio 1.0: 0.28.

Pereopod VI ( Fig. 53B View Fig ): coxal plate smaller than that of pereopod V, but highly similar in shape and 2 posterior setae. Basis ovoid-rectangular shaped, length: width ratio 1.0:0.51, 6 groups of 1–2 setae on anterior margin, 12 setae on posterior margin, 5 anteroapical setae of different lengths. Dactylus with 1 plumose seta on outer margin and 2 setae of different lengths near nail base. Nail 35% of total dactylus length. Ratio propodite: dactylus length 1.0: 0.34.

Pereopod VII ( Fig. 53C View Fig ): longest leg ( 5.65 mm) of inspected paratype male. Coxal plate trapezoidal, with 1 seta on posterior margin. Basis ovoid-rectangular, ratio length: width 1.0: 0.5, 5 groups of 1–2 setae on anterior margin, 14 setae on posterior margin and 4 anteroapical setae of different lengths. Dactylus with 1 plumose seta on outer margin and 2 setae of different lengths near nail base. Nail length 40% of total dactylus length. Ratio propodite: dactylus length 1.0: 0.3.

Pereopods V: VI: VII ratio 1.0: 1.22: 1.52.

Pleopods

Pleopods: similar (pleopod I depicted in Fig. 54A View Fig ), with unequal rami, 3 (pleopods I and II) and 4 (pleopods III) hooks on retinaculum.

Epimeral plates ( Fig. 54B View Fig )

Epimeral plate I with right postero-ventral angle, relatively straight ventral margin, convex posterior margin with 2 setae. Epimeral plate II with right postero-ventral angle, convex ventral margin with 1 antero-ventral spine, convex posterior margin with 8 setae. Epimeral plate III with right posteroventral angle, relative straight ventral margin with 2 antero-ventral spines, straight posterior margin with 9 setae.

Uropods

Uropod I ( Fig. 55A View Fig ): with two dorso-lateral rows of 4–5 spines on peduncle. Exopodite slightly longer than endopodite, ratio exopodite: endopodite lengths 1.0: 0.95. 1 strong spine at base of uropod I.

Uropod II ( Fig. 55B View Fig ): with 2 dorsal spine and 3 apical spines on peduncle. Endopodite slightly longer than exopodite, endopodite: exopodite length ratio 1.0: 0.96, both rami provided with 3–4 dorsal and 5–6 apical spines.

Uropod III ( Fig. 55C View Fig ): sexually differentiated, longer in males. Peduncle with 3 apical and 3 posterior setae. Short endopodite, 40% of length of peduncle, with 1 apical seta. Proximal segment of exopodite longer than distal segment (ratio 1.0: 0.7). Anterior margin of proximal segment of exopodite with 6 groups of 2–4 setae (including plumose setae); posterior margin of exopodite with 3 groups of 3–4 setae; 4 antero- and 4 postero-apical setae. Distal segment of exopodite with 3 groups of 1–2 setae on anterior margin, 3 groups of 1–2 setae on posterior margin, 4 apical and 4 subapical setae of different lengths.

Telson

Telson ( Fig. 55E View Fig ): nearly as wide as long (width: length ratio 0.95), with 2 subapical and 5 apical spines of different lengths on each lobe. Longest spine slightly longer than half of telson length. 2 thin setae of different lengths and plumose tip, 1 seta medially on 1 lobe.

Sexual dimorphism

The examined male and female are highly similar. Besides the usual sexual dimorphism (e.g., slightly smaller gnathopods, presence of oostegites, and slightly deeper coxal plates I– VI in females), in N. lotharingiensis sp. nov., the female uropod III ( Fig. 55D View Fig ) is shorter than that of the male, and the telson of the inspected female paratype is provided apically with 4 setae only on each lobe ( Fig. 55F View Fig ).

Type locality, ecology and distribution

The species is widely distributed in eastern France ( Fig. 56 View Fig ), with a slight geographical overlap with its sister species N. schellenbergi sensu stricto in the northeastern margin of its distribution range ( Fig. 2 View Fig ). It comprises two distinct genetic clades, of which one is very rare and currently only known from two sites in the eastern part of the species’ range. The type locality is the Tunnel du Col des Croix (connecting Vosges and Haute-Saône, France) at 47.8632° N, 6.7464° E, in the very east of the species known distribution (Supp. file 3.10). It is a 1087 m long abandoned railway tunnel with a 1 m rail gage once connecting Lure (Haute-Saône, France) with Le Thillot (Vosges, France). After its closure in 1962, it was used for the supply of potable water and was therefore locked.

Niphargus lotharingiensis sp. nov. can be found in a variety of subterranean biotopes (Supp. file 4.6). However, the inferred absence in the interstitial environment is most likely due to the fact that the species does not occur in the area where the interstitial environment was intensively sampled.