Niphargus bihorensis Schellenberg, 1940

Niphargus bihorensis Schellenberg, 1940 View in CoL

Type series. Meziad Cave, Romania (original label “Rumänien, Pesterea Meziadului, ca. 480 m. in einem grossen Tümpel”), 21.08.1938, legit R. Leruth, 7 males, 4 females; deposited in the Museum für Naturkunde , Berlin, Germany, catalogue number 25164. Considering that Schellenberg did not select a holotype but wrote on the label included in the vial “typus”, we selected one male (6.5 mm length) as lectotype, and 10 specimens (6 males and 4 females) as paralectotypes.

Type locality. Meziad Cave (= Peştera Meziad, coordinates WGS84 : longitude 22.478754 °E, latitude 46.763105°N), Apuseni Mountains (Western Carpathians), Bihor district, Romania GoogleMaps .

Other material examined. Meziad Cave, 29.09.2011, legit I. Meleg, several specimens (5 specimens used for morphological analysis, 9 specimens used for molecular analysis).

Description of male lectotype. Body length of 6.5 mm. Habitus as in fig. 3a View FIGURE 3 . Head length less than 10% of body length; rostrum absent. Pereonites I– VII with 2‒3 postero-ventral sensorial setae. Pleonites I–III with 2‒3 small dorsal sensorial setae and 2 postero-distal setae ( fig. 3a View FIGURE 3 ).

Antenna I ( fig. 3b View FIGURE 3 ) about 30% of body length. Flagellum of 18 articles; each article with 1 aesthetasc, its length about one third of article length; aesthetasc accompanied by 3‒4 setae. Distal article shorter than the aesthetasc of penultimate article, bearing 6 distal setae and 1 posterodistal seta. Peduncle triarticulated ( fig. 3b View FIGURE 3 ), proportions of articles length 1:2:3 as 1.0:0.7:0.2. Accessory flagellum biarticulated; distal article as long as one third of proximal article.

Antenna ii ( fig. 3c View FIGURE 3 ) as long as one half of antenna I. Flagellum of 9 articles; each article bearing an aesthetasc; distal article bearing 4 distal setae accompanied by 1 shorter aesthetasc. Peduncle with proportions of articles length 1:2:3 as 1.0:3.0:2.9; flagellum 70% of peduncle length.

Mandibles ( fig. 3d View FIGURE 3 ). Right mandible: incisor process with 4 teeth, lacinia mobilis with 2 teeth; between lacinia mobilis and pars molaris a row of thick, serrated setae is present; 3 small spines accompanying pars molaris. Left mandible ( fig. 3d View FIGURE 3 ): incisor process with 4 teeth, lacinia mobilis with 2 teeth; between lacinia mobilis and pars molaris a row of 7 thick, serrated setae is present; 3 small spines accompanying pars molaris; long seta accompanying pars molaris present. Proportions of mandibular palp articles ( fig. 3e View FIGURE 3 ) 1:2:3 as 1.0:2.5:2.4. Proximal palp article without setae; second article with 7 setae; distal article with 4 A setae on the outer side and 2 B setae on the inner side; C setae absent; 9 D setae and 4 E setae present, the distal one longer than the article.

Maxilla I ( fig. 3f View FIGURE 3 ). Palp articles ratio 1:3, with distal article bearing 4 apical setae. Outer lobe with 6 spines with 1 small tooth and the 7th, inner spine with several small teeth. Inner lobe elongated (3 times longer than wide), with 1 distal seta.

Maxilla ii ( fig. 3g View FIGURE 3 ). Inner lobe 0.8 times as long as outer lobe; both of them with the apical and subapical setae as usual in the genus.

Maxilliped. Palp ( fig. 3h View FIGURE 3 ) article 1 bearing 1 inner seta; article 2 with 26 inner setae; article 3 with 4 outer setae and 5 inner setae in the distal part, and a row of 6 distal medial setae; article 4 with 1 outer seta and with only 1 short seta close to the insertion of nail. Outer lobe ( fig. 3i View FIGURE 3 ) with 5 flattened, thick inner spines and 6 distal setae, proximal part of inner margin bearing 3 setae. Inner lobe ( fig. 3j View FIGURE 3 ) bearing 6 stout apical setae accompanied by 3 thick spines.

Gnathopod I ( fig. 4a View FIGURE 4 ). Coxa subquadrangular, with 7 short setae on anterior margin. Basipodite short and stout, 1.75 times longer than wide; ischiopodite, meropodite and carpopodite shape and setation as illustrated in fig.4a View FIGURE 4 . Propodite with convex, slightly inclined palm, bearing along posterior margin 4 groups of 3 setae each; anterior margin with sparse setae, and a row of 5 facial setae close to the insertion of palmar spine; antero-distal group of 5 setae close to the insertion of dactylopodite. Palmar corner with a strong palmar spine, accompanied by 2 short spines. Dactylopodite bearing 1 seta along anterior margin; distal nail as long as 2/3 of dactylopodite.

Gnathopod ii ( fig. 4c View FIGURE 4 ). Coxa subrounded; anterior margin with 6 short setae. Gill (epipodite) narrow, as long as basipodite. Basipodite elongated, 2.7 times longer than wide; ischiopodite, meropodite and carpopodite shape and setation as illustrated in fig. 4c View FIGURE 4 . Propodite 1.3 times longer than propodite of gnathopod I; palm convex and less inclined than palm of gnathopod I, bearing along posterior margin 5 dense rows of setae; palmar anterior margin with few setae, and an irregular row of 4 facial setae close to the insertion of palmar spine; antero-distal group of 6 setae close to the insertion of dactylopodite. Palmar corner with a strong palmar spine accompanied by 1 short and stout spine. Dactylopodite bearing 1 seta along anterior margin; distal nail longer than one half of dactylopodite.

Pereopods iii–iv ( fig. 4d, e View FIGURE 4 ). Coxal III‒IV plates subquadrate with 5 marginal setae each; gill III and IV as long as basis, and longer than basis, respectively; gills narrow. Pereopods III and IV approximately subequal (ratio III:IV as 1.1:1), shape and setation as in fig. 4d, e View FIGURE 4 . Dactylopodites III–IV with a single dorsal plumose seta, and one short spine on ventral side, close to the insertion of nail.

Pereopods v–vii ( fig. 5 View FIGURE 5 ). Proportions of pereopods V: VI: VII as 1.00:1.7:1.8, shape and setation as in fig. 5 View FIGURE 5 . Pereopod VII ( fig. 5c View FIGURE 5 ) length about 40% of body length. Coxa V – VI narrow and elongated, ratio width:maximum length about 2.2, bearing few short setae; coxa VII small, subrounded, 2.5x wider than long with 2 posterior setae. Gills (epipodites) on pereopod V and VI as long as coxal width. Basipodites V ‒ VII, with straight or slightly concave posterior margins, without distal lobes; posterior margins with a regular row of short setae; anterior margins with setae only. Ischiopodites V ‒ VII with a marked notch. Dactylopodites V-VII with nails length about one third of total dactylus length; dorsal margins with a single plumose seta; ventral margin bearing only one short spine, accompanied by a tiny seta, near nail insertion ( fig. 5d View FIGURE 5 ).

Pleopods ( fig. 6c View FIGURE 6 ). Pleopods I–III protopo- dites (peduncles) with 3 hooked retinacles. Rami (exopods and endopods) of 7 articles with 2 long plumose setae each.

Uropods. Uropod I ( fig. 6f View FIGURE 6 ) protopodite with 2 longitudinal rows of 3‒4 dorsal spines and 2 distal spines close to the insertion of exopodite; length ratio endopodite:exopodite as 1.0:0.9, rami quite straight; endopodite with 1 dorsal spine and 3 terminal spines; exopodite with 1 dorsal spine and 4 terminal spines. Uropod II ( fig. 6f View FIGURE 6 ) protopodite short, one-half length of uropod I protopodite, with 2 dorsal spines, and 2 distal spines close to the insertion of exopodite; endopodite and exopodite subequal in length, bearing 1 dorsal spine and 3‒4 distal spines. Uropod III ( fig. 6d View FIGURE 6 ) as long as 45% of body length; protopodite 1 distal spine close to the insertion of exopodite; endopodite ( fig. 6e View FIGURE 6 ) short (2 times longer than wide), 30% of protopodite length, apically with 2 setae and no spines; exopodite 2-articulated, distal article elongated, approximately 70% of proximal article; proximal article with 4 groups of 2‒3 spines; distal article with setae only, as in fig. 6d View FIGURE 6 .

Telson ( fig. 6g View FIGURE 6 ). Telson 2.5 times longer than wide, cleft 80% of length; lobes apically bearing 4 spines each, as long as 1/3 of lobe; lateral margin with 2 plumose setae; dorsal surface without setae and spines.

Epimeral plates ( fig. 6b View FIGURE 6 ). Epimeral plate I with 2 posterior setae; plate II and III with 2 submarginal ventral spines and 2 posterior spines; plate III with posterior margin slightly convex, posterior ventral corner slightly rounded.

Urosomites ( fig. 6f View FIGURE 6 ) with 0‒2 dorso-lateral setae. One short spine present near uropod I insertion.

Description of female paralectotype. Habitus as in male; adult females with large oostegites, illustrated for gnathopod II in fig. 4b View FIGURE 4 . Gnathopod II slightly smaller than in male ( fig. 4b View FIGURE 4 ). Uropod III exopodite shorter than in male ( fig. 6h View FIGURE 6 ), distal article flattened, about 40% of proximal article in length. Setation as in fig. 6h View FIGURE 6 .

Remarks. In the original description by Schellenberg (1940) the four drawings were quite poor and with few details, taken from a 6.5 mm long male, i.e., the same described above. For this reason, and given the presence of a cryptic species, the first detailed description of the species is reported above.