Niphargus qazvinensis, Mirghaffari & Esmaeili-Rineh, 2025

Mirghaffari, Seyyed Ahmad & Esmaeili-Rineh, Somayeh, 2025, The discovery of a new Niphargus species from the southern part of the Alborz Mountains, located at the eastern limit of the genus range, Zootaxa 5636 (3), pp. 473-486 : 477-480

Niphargus qazvinensis sp. nov.

Figures 4–7

Material examined. Holotype, ZCRU Amph.1504 , male specimen (8.0 mm) from Samaq Abad Spring , Abyek City, Qazvin Province, Iran, coordinates (N 36°11’26’’, E 50°36’54’’), collected by S.A. Mirghaffari on 22 June 2022 . Paratypes: ZCRU Amph.1504 , six specimens, data same as for holotype .

Etymology. The species was named “qazvinensis ” after Qazvin City, the provincial center where it was discovered.

Diagnosis. The outer plate of maxilla I is characterized by seven robust setae, with none to two lateral projections. The propodus of gnathopods I to II bear three and two robust setae with lateral projections on outer surface in palmar corner, respectively. The gnathopod II dactylus bears one and three simple setae on outer and inner margins, respectively. Urosomites II and III have two and one robust setae on postero-dorsal margin, respectively. The uropod I is 2/3 as long as uropod III, and the inner ramus of uropod I is longer than outer ramus. Pereopod VII and antenna I are less than half of the total body length.

Description. Holotype, male 8.0 mm. Body strong and stout. Head length 13% of body length. Lateral cephalic lobes sub-rounded ( Figure 4A ).

Antennae I. Antennae I 0.47 of body length. Peduncular articles 1–3 progressively shorter; peduncular articles 2: 3 (ratio 1: 0.43); main flagellum with 17 articles (most of which with short simple setae); accessory flagellum bi-articulated and reaching 1/3 of article 4 of main flagellum, articles with two and three simple setae, respectively ( Figure 4B ).

Antennae II. Length ratio antenna I: II as 1: 0.74. Peduncular article 4 longer than article 5, with six and seven groups of simple setae, respectively; flagellum with eight articles. Length of flagellum: length of peduncle article 4 + 5 as 0.59: 1 ( Figure 4C ).

Labium. Labium with inner lobes and simple setae on the tip of lobes ( Figure 5D ).

Maxilla I. Inner plate of maxilla I with two long simple setae; outer plate with seven toothed robust setae each with 0–2 strong lateral teeth; palp bi-articulated, shorter than outer lobe, with four long distal simple setae ( Figure 4 E-F).

Maxilla II. Both plates of maxilla II with numerous distal simple setae ( Figure 5E ).

Right mandible. Incisor with four teeth, lacinia mobilis pluritooth; six simple setae with lateral projections between lacinia and triturative molar ( Figure 4G ).

Left mandible. Incisor with five teeth, lacinia mobilis with four teeth; nine simple setae with lateral projections between lacinia and triturative molar ( Figure 4H ).

Mandibular palp. Articles in ratio 1: 2: 3 as 1: 1.85: 2. The proximal article has no setae, the second article with eight simple setae along inner margin and the third article with one group of three A-setae, three groups of Bsetae, no C-setae, 12 D-setae and four E-setae ( Figure 4D ).

Maxilliped. With short inner plate on which are three distal robust setae intermixed with four distal simple setae and three inner marginal simple setae; outer plate exceeding half of the posterior margin of palp article 2, with 10 robust setae along inner margin and two simple setae distally. Palp article 3 of maxilliped with one proximal, inner and outer group of long simple setae at outer margin; terminal article of palp with one simple seta at outer margin, nail shorter than pedestal ( Figure 5C ).

Gnathopod I. Coxa of gnathopod I shorter than gnathopod II. Coxa I with square shape, ventral to anterior margin with five simple setae. Basis with simple setae on anterior and posterior margins; ischium and merus with posterior group of simple setae. Carpus with one group of four simple setae antero-distally, a bulge with long simple setae; carpus 0.55 of basis length and 0.73 of propodus length. Propodus anterior margin with four simple setae in addition to antero-distal group of four simple setae. Palm slightly convex, with one strong long palmar robust seta, one short supporting robust seta on inner surface and three robust setae with lateral projections on outer surface; two simple setae under supporting robust seta in palmar corner. Dactylus reaching posterior margin of propodus, outer margins with a row of two simple setae; nail short, 0.29 of total dactylus length ( Figure 5A ).

Gnathopod II. Coxa of gnathopod II rectangular, with five simple setae along antero-ventro-posterior margins. Basis with simple setae in groups and single simple setae along anterior and posterior margins; posterior margins of ischium and merus with one posterior group of simple setae each. Carpus 0.5 of basis length and 0.7 propodus length. Carpus with one group of two simple setae antero-distally. Propodus in gnathopod II larger than gnathopod I, trapezoid shape and broader than long; anterior margin with three simple setae in one group in addition to antero-distal group of five simple setae. Palm nearly convex, with one strong palmar robust seta, one supporting robust seta without lateral projections on inner surface, and two robust setae with lateral projections on outer surface; one simple seta under supporting robust seta in palmar corner. Dactylus reaching posterior margin of propodus, with one and three simple setae on outer and inner margins, respectively. Nail length 0.32 of total dactylus length ( Figure 5B ).

Coxa III–VII. Coxa III rectangular, length to width ratio as 1.16: 1; antero-ventral margin with four simple setae. Coxa IV rectangular, length to width ratio as 1.3: 1, antero-ventral margin with four simple setae, posterior concavity shallow and approximately 0.05 of coxa width. Coxa V with anterior lobe, with six and one simple setae on anterior and posterior lobes, respectively. Coxa VI with anterior lobe, with one simple seta on posterior lobe. Coxa VII with one simple seta ( Figure 6A–E ).

Pereopods. Pereopod III: IV lengths ratio as 1: 1.07. Nail: dactylus and dactylus: propodus length ratios are 0.37 and 0.44 for pereopod III, 0.30 and 0.43 for pereopod IV. Dactyli of pereopods III–IV with one robust seta at the base of nail on inner margin.

Pereopods V: VI: VII length ratios as 1: 1.12: 1.2, respectively. Pereopod VII 0.47 of body length. Pereopod bases VI–VII each with six and four groups of robust setae along posterior margins and with nine and eight simple setae along anterior margins, respectively. Pereopod basis V with five groups of robust setae along anterior margin and six simple setae along posterior margin, respectively. 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 along anterior and posterior margins; propodus of pereopod VII longer than these in V–VI. Dactyli of pereopods V–VII with one robust seta at the base of nail on inner margin; dactyli of pereopods VI–VII with one simple seta on outer margin; nail length of pereopod VII 0.3 of total dactylus length ( Figure 6A–E ).

Pleopods I–III: Peduncle of pleopods I–III with two-hooked retinacles at distal part of inner margin; Peduncle of pleopod I with three simple setae along of outer margin; Peduncle of pleopod II with one simple seta at distal part of outer margin; rami of pleopods I–III each with seven to 11 articles ( Figure 7A–C ).

Pereonites I–VII: Without setae.

Pleonites I–III: each with one seta along the dorsal margin.

Urosomites I–III. At base of uropod I with one robust seta. Urosomite I with one robust seta and one simple seta on posterior-dorsal margin, urosomites II–III with two and one robust setae on posterior-dorsal margin, respectively.

Uropods I–III. Peduncle of uropod I with six and three large robust setae along dorso-lateral and dorso-medial margins, respectively. Inner ramous is longer than outer ramus; inner ramus with four groups of robust setae laterally and five robust setae distally; outer ramus with two groups of intermixed robust setae and simple setae laterally and four robust setae distally. Inner ramus in uropod II longer than outer, both rami with lateral and distal long robust setae. Uropod III short, almost 0.22 of body length. Peduncle of uropod III with four robust setae, Outer ramus bi-articulated, distal 0.35 proximal articles. The proximal article of outer ramus bearing five groups of robust setae along both margins; distal article with simple setae laterally and three simple setae distally. Inner ramus short, with two distal robust setae ( Figure 7D–F ).

Epimeral plates I–III: With angular postero-ventral corner, anterior and ventral margins convex; postero-ventral corners of plates I–II each with one robust seta and three simple setae, respectively; postero-ventral corners of plate III with one robust seta and four simple setae. Epimeral plates II-III with three and four robust setae along of ventral margins, respectively ( Figure 7G ).

Telson. Broader than long, each lobe with four robust setae distally, with one long robust seta and two simple setae marginally ( Figure 7H ).

Interpopulational variation. While many taxonomic traits seem to be consistent, there were noticeable differences in the shape of propodus of gnathopod II (rectangular to trapezoid shape), and the number of distal and lateral robust setae on each lobe of the telson. Two individuals have four robust setae distally and one robust seta and two simple setae laterally, while two other individuals have three robust setae distally and one robust seta and two simple setae laterally on each lobe of the telson.

Remarks and affinities. Based on COI and 28S rDNA genes (see Figures 2–3 ), N. qazvinensis is genetically closest to N. urmiensis , N. hakani , and N. fiseri .Although, N. urmiensis and N. qazvinensis share some morphological traits, such as the shorter length of the maxillar palpus to the outer plate in maxilla I and similar shapes of the postero-ventral angle of epimeral plates I–III. However, N. qazvinensis can be distinguished from N. urmiensis by trapezoidal shape of gnathopod II propodus (compared to rectangular shape in N. urmiensis ), the presence of a lateral robust seta on the telson, the shorter size of coxa I to II (compared to equal size of coxae in N. urmiensis ), the inner ramus longer than outer ramus in uropod I and the ratio of uropod I length to uropod III. Uropod I is more than 70% the length of Uropod III in N. qazvinensis , whereas in N. urmiensis , uropod I is half the length of uropod III ( Mamaghani-Shishvan and Esmaeili-Rineh, 2019).

Niphargus qazvinensis shares some morphological traits with N. fiseri , such as the presence of one lateral robust seta on the telson lobes, and the inclined angle of epimeral plates I–III. However, N. qazvinensis can be distinguished from N. fiseri by several features: the longer length of pereopod VII compared to pereopod VI (whereas in N. fiseri , pereopod VII is 80% the length of pereopod VI), the longer inner to outer ramus in uropod I (shorter in N. fiseri ), and the presence of only one supporting robust seta on the inner surface of propodi of gnathopods I and II ( N. fiseri has two supporting robust setae on the inner surface of propodi of both gnathopods) ( Mamaghani-Shishvan and Esmaeili-Rineh, 2019).

Niphargus qazvinensis shares several features with N. hakani , including the trapezoidal shape of propodus of gnathopods I and II, the presense of one supporting robust seta on the inner surface of propodus of gnathopods I and II, the shorter length of pereopod VI to VII, and the presense of one lateral robust seta on the telson lobe. However, N. qazvinensis differ from N. hakani in several ways, such as the shorter length of the maxillar palpus to the outer plate in maxilla I ( N. hakani has a long palpus in maxilla I, which passes from the tip of the outer lobe), the dactylus reaching the posterior margin of propodus of gnathopod II, the shorter length of distal to proximal article of the outer ramus of uropod III (compared to equal size of distal to proximal article of the outer ramus of uropod III in N. hakani ) and the presence of four distal long robust setae on each telson lobe (compared to three distal long robust setae on each telson lobe in N. hakani ) ( Esmaeili-Rineh et al., 2017).

Figures

FIGURE 2. Bayesian consensus tree of 26 Niphargus species (Esmaeili-Rineh et al., 2015, Esmaeili-Rineh & Mirghaffari, 2021), based on the 28S ribosomal DNA sequences. Species are identified and named according to available taxonomic descriptions. Maximum likelihood topology was identical. Number above line indicates the posterior probabilities of the nodes in the Bayesian Inference analysis. Number below line is the ultrafast bootstrap values of the nodes in the Maximum likelihood.

FIGURE 3. Bayesian consensus tree of 21 Niphargus species (Esmaeili-Rineh et al., 2015, Esmaeili-Rineh & Mirghaffari, 2021), based on the COI sequences. Species are identified and named according to available taxonomic descriptions. Maximum likelihood topology was identical. Number above line indicates the posterior probabilities of the nodes in the Bayesian Inference analysis. Number below line is the bootstrap values of the nodes in the Maximum likelihood.

FIGURE 4. Niphargus qazvinensis sp. nov., Samaq Abad Spring, male 8 mm (holotype). A, Head; B, Antenna I; C, Antenna II; D, Mandibular palp; E-F, Maxilla I; G, Right mandible; H, Left mandible. Scale bars: 1= 0.25 mm (G–H); 2= 0.5 mm (A, D–F); 3= 1mm (B–C).

FIGURE 5. Niphargus qazvinensis sp. nov., Samaq Abad Spring, male 8 mm (holotype). A, Gnathopod I; B, Gnathopod II; C, Maxilliped; D, Labium; E, Maxilla II. Scale bars: 1= 0.5 mm (D–E); 2= 1mm (A–C).

FIGURE 6. Niphargus qazvinensis sp. nov., Samaq Abad Spring, male 8 mm (holotype). A, Pereopod III; B, Pereopod IV; C, Pereopod V; D, Pereopod VI; E, Pereopod VII. Scale bars: 1mm.

FIGURE 7. Niphargus qazvinensis sp. nov., Samaq Abad Spring, male 8 mm (holotype). A, Pleopod I; B, Pleopod II; C, Pleopod III; D, Uropod I; E, Uropod II; F, Uropod III; G, Epimeral plates I-III; H, Telson Scale bars: 1= 0.5 mm (G–H); 2= 1mm (A–E); 3= 2mm (F).