Niphargus hakani, Esmaeili-Rineh, Somayeh, Mirghaffari, Seyyed Ahmad & Sharifi, Mozafar, 2017

Esmaeili-Rineh, Somayeh, Mirghaffari, Seyyed Ahmad & Sharifi, Mozafar, 2017, The description of a new species of Niphargus from Iran based on morphological and molecular data, Subterranean Biology 22, pp. 43-58 : 46-50

Niphargus hakani sp. n.

Material examined and type locality.

Holotype, male specimen (9 mm) from Kheder-Goli spring, Razan city, Hamedan Province, Iran; coordinates 35°27'N, 49°07'E. Specimens were collected by S. A. Mirghaffari in September 2014. Holotype with two paratypes is stored under catalogue number ZCRU Amph.1010 in the Zoological Collection of Razi University, Iran (ZCRU).

Diagnosis.

At the base of uropod I observed only one robust seta. The palpus of maxilla I is slightly longer than outer lobe. Urosomites I–III bear two, five and two robust setae on dorso-lateral margin. Epimeral plates distinctly pointed and have three and four robust setae in ventral margin of plates II-III. The propodi of gnathopods I-II are trapezoid. Dactylus of gnathopod I dose not reach to posterior margin of propodus. Third article of mandibular palp bears a single group of two A-setae.

Description of holotype.

Total length of specimen 9 mm. Body strong and stout. Head length 11% of body length (Figure 2). Antennae I (Figure 2A) 0.6 of body length. Peduncular articles 1-3 progressively shorter; peduncular articles 2: 3 (ratio 1: 0.75); main flagellum with 19 articles (most of which with short setae); accessory flagellum biarticulated and reaching 1/3 of article 4 of main flagellum, both articles with two simple setae, respectively (Figure 2A). Length ratio antenna I: II as 1: 0.46. Peduncular article 4 slightly as long as article 5, each with seven groups of simple setae; flagellum with five articles. Length of flagellum: length of peduncle article 4 + 5 as 0.57: 1(Figure 2B).

Labium (Figure 3D) with inner lobes and setae on the tip of lobes. Inner plate of maxilla I with two long simple setae; outer plate with seven bi-, pluri or without lateral projections; palp biarticulated, slightly longer than outer lobe, with three long distal simple setae (Figure 2 D–E). Both plates of maxilla II with numerous distal simple setae (Figure 3E).

Incisor in left mandible with five teeth, lacinia mobilis with four teeth; seven setae with lateral projections between lacinia and triturative molar (Figure 2F). Incisor in right mandible with four teeth, lacinia mobilis pluritooth; five setae with lateral projections between lacinia and triturative molar (Figure 2G). Mandibular palp articles in ratio 1: 2: 3 as 1: 2.46: 2.76. The proximal article has no setae, the second article with six setae along inner margin and the third article with one group of two A-setae, two groups of B-setae, no C-setae, 15 D-setae and four E-setae (Figure 2H).

Maxilliped with short inner plate on which are four distal robust setae intermixed with five distal simple setae; outer plate exceeding half of the posterior margin of palp article 2, with 11 robust setae along inner margin and three 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 3C).

Coxa of gnathopod I shorter than gnathopod II. Coxa I rectangular, longer than broad, ventral to anterior margin with four and three simple setae, respectively. Basis with setae on anterior and posterior margins; ischium and merus with posterior group of setae. Carpus with one group of three setae anterodistally, a bulge with long simple setae; carpus 0.42 of basis length and 0.79 of propodus length. Propodus slightly longer than broad; anterior margin with seven setae in two groups in addition to anterodistal group of six simple setae. Palm slightly convex, with one strong long palmar robust seta, one short supporting robust seta on inner surface and two robust setae with lateral projections on outer surface; two simple setae under supporting robust seta in palmar corner. Dactylus not reaching posterior margin of propodus, outer and inner margins with a row of three and five simple setae, respectively; nail short, 0.23 of total dactylus length (Figure 3A).

Coxa of gnathopod II slightly rounded, with six setae along antero-ventro-posterior margins. Basis with setae in groups and single setae along anterior and posterior margins; posterior margins of ischium and merus with one posterior group of setae each. Carpus 0.43 of basis length and 0.67 propodus length. Carpus with one group of four setae anterodistally. Propodus in gnathopod II larger than gnathopod I, trapezoid shape and broader than long; anterior margin with seven setae in one group in addition to anterodistal group of six simple setae. Palm nearly convex, with one strong palmar robust seta, one supporting robust seta without lateral projections on inner surface, and one robust seta with lateral projections on outer surface; two setae under supporting robust setae in palmar corner. Dactylus reaching posterior margin of propodus, outer and inner margins of dactylus with three and four simple setae, respectively. Nail length 0.25 of total dactylus length (Figure 3B).

Coxa III rectangular, length to width ratio as 1.29: 1; antero-ventral margin with five simple setae. Coxa IV rectangular, length to width ratio as 1: 1.04, antero-ventral margin with seven simple setae, posterior concavity shallow and approximately 0.1 of coxa width (Figure 4 A–B). Coxa V with anterior lobe, with five and three simple setae on anterior and posterior lobe, respectively. Coxa VI with anterior lobe, with one simple seta on posterior lobe. Coxa VII with one simple seta (Figure 4 C–E).

Pereopod III: IV lengths ratio as 1: 1.35 (Figure 4A-B). Dactylus IV short, length of dactylus 0.40 of propodus, nail shorter than pedestal (Figure 4B). Pereopods V: VI: VII length ratios as 1: 1.35: 1.30, respectively. Pereopod VII 0.63 of body length. Pereopod bases V-VI each with seven simple setae along posterior margin and six and seven groups of robust setae along anterior margins, respectively. Pereopod basis VII with 10 simple setae and six groups of robust setae along posterior and anterior margins, respectively (Figure 4 C–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 along anterior and posterior margins; propodus of pereopod VII longer than these in V-VI, dactyli of pereopods V–VII with one robust and one short simple seta at the base of nail on inner margin, nail length of pereopod VII 0.29 of total dactylus length (Figure 4 C–E).

Epimeral plates I–III (Figure 5G) with angular postero-ventral corner, anterior and ventral margins convex; postero-ventral corners of plates I-III with one robust seta each, and with two, three and two simple setae posteriorly, respectively. Epimeral plates II-III with three and four robust setae along of ventral margins, respectively. Peduncle of pleopod I with one simple seta and two-hooked retinacles at distal part of inner margin (Figure 5A); peduncle of pleopods II-III with two-hooked retinacles at distal part of inner margin; rami of pleopods I–III each with seven to 10 articles (Figure 5 A–C).

Pereonites I–VI without setae. Pereonite VII with two simple setae. Pleonites I–III each with one long simple seta along dorsal surface. Urosomites I-III with two, five and two robust setae laterally, respectively.

Peduncle of uropod I with six and three large robust setae along dorsolateral and dorsomedial margins, respectively. Rami of uropod I with equal length (ratio 1: 1); inner ramus with three groups of robust setae laterally and five robust setae distally; outer ramus with three groups of six robust setae laterally and five robust setae distally (Figure 5D). Outer ramus in uropod II longer than inner, both rami with lateral and distal long robust setae (Figure 5E). Uropod III long, almost 0.45 of body length. Peduncle of uropod III with five robust setae, Outer ramus biarticulated, distal: proximal article as 1: 1.92. The proximal article of outer ramus bearing five groups of robust setae along inner and outer margins (Figure 5F); distal article with simple setae laterally and seven simple setae distally. Inner ramus short, with one robust and one simple distal seta. Telson two times as long as broad, lobes slightly narrowing; each lobe with three robust setae distally, with one long robust and one plumose seta marginally (Figure 5H).

Etymology.

The name “hakani” refers to Hakan village where specimens were found.

Phylogenetic position of N. hakani sp. n. species.

This species is nested within the main Iranian clade and apparently shares the nearest common ancestor with N. khwarizmi , N. khayyami , N. kermanshahi and N. bisitunicus (Figure 6, please note weak node support). Among these, this species is genetically the most similar to N. khwarizmi (1.93% K2P divergence in the studied 28 rDNA gene fragment) and the most divergent species from N. bisitunicus , (2.20% K2P divergence).