Niphargus borisi, Esmaeili-Rineh, Somayeh, Sari, Alireza & Fišer, Cene, 2015

Esmaeili-Rineh, Somayeh, Sari, Alireza & Fišer, Cene, 2015, Making future taxonomy of Niphargus (Crustacea: Amphipoda: Niphargidae) in the Middle East easier: DELTA database of Middle East species with description of four new species from Iran, Zootaxa 4020 (3), pp. 401-430 : 408-413

Niphargus borisi sp. nov.

(Figs 6–9)

Material examined and type locality. Holotype, male ZUTC Amph. 2333. Belqais spring ( Fig. 1 ), 4 Km to Choram city, Kohgiloyeh va Boyer-Ahmad Province, Iran (30°45′N, 50°44′E). Three male paratypes, ZUTC Amph.2346.

Diagnosis. Urosomite I with two robust setae at the base of uropod I and urosomite III with robust setae along dorso-lateral margin, respectively. Gnathopods small, gnathopod II with two strong robust setae along medial margin.

Description of holotype. Body length 9 mm. Body stout, Head length 12% of body length.

Antennae I (fig. 6A). Antenna I 0.34 of body length. Peduncular articles 1–3 progressively shorter; length of peduncular article 3 more than half of peduncular article 2; main flagellum with 19 articles; accessory flagellum biarticulated and reaching beyond one-third of article 2 of main flagellum; first and second articles each with two simple setae.

Antennae II (fig. 6B). Antenna II as long as 0.46 of antenna I. Peduncular article 5 slightly shorter than article 4, ratio between articles 4:5 equal to 1.05: 1, each with six groups of simple setae; flagellum with seven articles, approximately 0.81 of length of peduncle articles 4 + 5.

Labium (fig. 7B) with inner lobes.

Maxilla I (fig. 6C–D). Inner plate with one long simple seta, outer plate with seven long robust setae of which two with two, two with one and three without lateral projections; palp bi-articulated, normal, with two long distal simple setae.

Maxilla II (fig. 6H). Both plates with numerous long distal simple setae.

Mandibular palp (fig. 6E). Ratio of mandibular palp articles 1: 2: 3 equal to 1: 2.14: 3.14, no setae on first article; second article with four simple setae medially; third article with one group of two A-setae, two single Bsetae, no C-setae, 10 D-setae and four E-setae.

Left mandible (fig. 6F). Incisor with five teeth, lacinia mobilis pluritooth; five setae with lateral projections between lacinia and triturative molar.

Right mandible (fig. 6G). Incisor with four teeth, lacinia mobilis with four teeth; eight setae with lateral projections between lacinia and triturative molar.

Maxilliped (fig. 7A). Inner plate short, with four distal robust setae intermixed with seven simple setae, subdistally with two simple long lateral setae; outer plate exceeding half of the posterior margin of palp article 2, with nine marginal robust setae and five distal simple setae; palp article 3 at outer margin with one proximal, distal and medial group of long simple setae; terminal article of palp with one simple seta in outer margin, nail shorter than pedestal.

FIGURE 6. Niphargus borisi , sp. nov., Belqais Spring, male 9 mm (holotype). A, A1; B, A2; C–D, MX 1; E, MNDP; F, LMND; G, RMND; H, MX 2. Scale bars: 1= 0.25 mm (F–G); 2= 0.5 mm (C–E, H); 3= 1mm (A–B).

FIGURE 7. Niphargus borisi , sp. nov., Belqais Spring, male 9 mm (holotype). A, MXP; B, L; C, GN 1; D, GN 2. Scale bars: 1= 0.5 mm (A–B); 2= 1mm (C–D).

Gnathopod I (fig. 7C). Coxa of gnathopod I smaller than gnathopod II; rounded, broader than long, ventral and anterior margins with five and six simple setae, respectively. Basis with single setae on anterior and posterior margins; ischium and merus with one posterior group of setae. Carpus with one group of setae antero-distally and setae in rows on the proximo-posterior bulb and along postero-medial margin. Carpus 0.91 of basis length and equal to propodus length. Propodus longer than broad, posterior margin slightly rounded; anterior margin with four setae in one group in addition to antero-distal group with four setae, medial surface of propodus with two setae; palm slightly convex, with one strong long palmar robust seta, one short supporting robust seta on inner surface and one short robust seta with lateral projections on outer surface. Dactylus not reaching posterior margin of propodus, outer and inner margins with a row of four and seven simple setae, respectively, nail short, length 0.21 of total dactylus length.

Gnathopod II (fig.7D). Coxa II trapezoid, with six and one simple setae on ventral and anterior margins, respectively. Anterior and posterior margins of basis with single setae, posterior margin of ischium and merus with one posterior group of setae. Carpus 0.63 of basis length and 0.8 propodus length. Carpus with single antero-distal group of setae and setae in rows on the proximo-posterior bulb and along postero-medial margin. Propodus in gnathopod II larger than gnathopod I, rectangular, longer than broad, anterior margin with three simple setae in one group in addition to six antero-distal setae, with medial setae on surface of propodus. Palm slightly convex, with one strong palmar robust seta, three robust setae without lateral projections on inner surface, and with two robust setae with lateral projections on outer surface. Dactylus reaching posterior margin of propodus, outer margins of dactylus with one long simple seta, nail length 0.29 of total dactylus length.

Coxae III–VII (fig. 8A–E). Length to width ratio in coxa III 1: 2, ventro-antero-posterior margins of coxa III with six and two simple and robust setae, respectively. Coxa IV length to width ratio as 2: 1, ventral margin with six simple setae, posterior concavity shallow and approximately 0.05 of coxa width (fig. 8A–B). Coxa V anterior lobe larger than posterior, with three simple setae in each lobe. Coxa VI posterior lobe larger than anterior, one robust seta and two simple setae along posterior and anterior lobes, respectively. Coxa VII with one seta in posterior margin (fig. 8C–E).

Pereopods III–VII (fig. 8A–E). Pereopod III shorter than IV with length ratio of 1: 1.04 (fig. 8A, B); dactyli of pereopods III–IV short, each with one robust seta and one simple seta along inner and outer margins, respectively; in pereopod IV length of nail 0.33 of dactylus (fig. 8B).

Length ratio of pereopods V: VI: VII equal to 1: 1.41: 1.42. Pereopod VII 0.36 of body length. Bases in pereopods V–VII with seven, five and five groups of robust setae along posterior and 11, 11 and 10 short simple setae along anterior margin, respectively (fig. 8C–E). Postero-ventral lobe of ischium in pereopods V–VII developed. Ischium, merus and carpus in pereopods V–VII with several groups of robust and simple setae on anterior and posterior margins; propodus of pereopod VII slightly longer than these in V and VI, dactyli of pereopods V–VII similar to pereopod III, nail length of pereopod VII, 0.29 of total dactylus length (fig. 8C–E).

Pereonite I. With two simple setae.

Pereonites II–VII. No setae.

Pleonites I–III. With four, six and six simple setae along the dorsal margin, respectively.

Pleopods I–III (fig. 9A–C). Peduncle of pleopods I–III with two hooked retinacula at distal part of inner margin, peduncle of pleopod II with one long simple seta on distal surface; rami of pleopods I with 8–9 articles, rami of pleopods II–III each with 7–8 articles.

Epimeral plates I–III (fig. 9D) with pointed postero-ventral corner, posterior and ventral margins concave and convex respectively. Epimeral plates I–II with one long robust seta and two short simple setae along posterior margin, epimeral plate III with one long robust seta and three short simple setae at posterior margin; ventral margin of plate II with three simple setae and ventral margin of plates III with two simple setae and one robust seta.

Urosomites I–III. Postero-dorsally with four, four and two robust setae. No seta laterally. Urosomites I–II with six and four simple setae at dorsal margin. At the base of uropod I with two strong robust setae.

Uropods I–III (fig. 9E–G). Peduncle in uropod I with six and three large robust setae along dorso-lateral and dorso-medial margins, respectively. Ratio of inner to outer ramus length 1.16: 1. Inner ramus with four single robust setae laterally and five robust setae distally. Outer ramus with four groups of robust setae laterally and five single robust setae distally (fig. 9E). Inner ramus in uropod II slightly longer than outer, both rami with lateral and distal long robust setae (fig. 9F). Uropod III normal, almost 0.21 of body length. Peduncle of uropod III with eight robust setae distally, proximal article of outer ramus with five and six groups of robust setae along inner and outer margins, respectively (fig. 9G); with one simple seta at inner margin; distal to proximal article ratio of outer ramus 0.17: 1.19, with lateral simple seta and four distal simple setae; inner ramus short, with three distal robust setae.

Telson (fig. 9H). Three times as long as broad, telson cleft about one half of telson length, each lobe with three distal long robust setae, with one long robust seta and one simple seta marginally.

Etymology. The species is named in honor of Professor Boris Sket, University of Ljubljana, Slovenia who dedicated his career to exploration of diversity of subterranean fauna, including amphipods from genus Niphargus .

FIGURE 9. Niphargus borisi , sp. nov., Belqais Spring, male 9 mm (holotype). A, PL 1; B, PL 2; C, PL 3; D, EP 1–3; E, USM; F, U 2; G, U 3; H,T. Scale bars: 1= 0.5 mm (D, H); 2= 1mm (A–C, E–F); 3= 2 mm (G).

Remarks and affinities. Niphargus borisi is diagnosed mainly with two rare characters. The first one is multiple robust setae at the base of uropod I. This character was observed in N. bodoni ( Italy, Karaman 1985) and N. sertaci ( Turkey, Fišer et al. 2009b). The second character comprises robust setae on urosomite III. This character has been reported in few species from Dinaric Mountains e.g., N. hadzii (pers. obs.), and three largebodied species from Balkan, namely N. hercegovinensis , N. trullipes and N. croaticus (see Karaman 1984). None of these species, however, has more than one robust seta at the base of the uropod I.

We included an additional character in the diagnosis. This character is increased number of supporting robust setae on gnathopod II. Increased number of supporting robust setae has been so far reported only from one species in Europe ( N. kenki , Karaman 1952), but it seems to be more common in Iran (see also other diagnoses in this paper).

Figures

FIGURE 1. Distribution map of the genus Niphargus in Iran and Middle East.