Niphargus darvishi, 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 : 414-418

Niphargus darvishi sp. nov.

(Figs 10–13)

Material examined and type locality. Holotype, male ZUTC Amph. 2322. Dimeh spring ( Fig. 1 ), Kohrang city, Chahar-mahal va Bakhteyari Province, Iran (N 32° 30′, E 50°13′). Five male paratypes, ZUTC Amph.2347.

Diagnosis. Maxilla I with pluritooth robust setae on outer lobe. Propods of gnathopods large, broader than long. Bases of pereopods V–VII mid-sized (neither narrow nor broad). Dactyli of pereopods III–VII with more than two robust setae along inner margin. Urosomite I with two robust straight postero-distal setae. Epimeral plate III distinctly produced disto-posteriorly.

Description of holotype. Body length 13 mm. Body strong and stout. Head length 11% of body length.

Antennae I (fig. 10A). Antenna I 0.51 of body length. Peduncular articles 1–3 progressively shorter; length of peduncular article 3 less than one half of peduncular article 2; main flagellum with 29 articles (most of which with short setae); accessory flagellum bi-articulated and reaching beyond two-third of article 1 of main flagellum; second article with two simple setae (fig. 10A).

Antennae II (fig. 10B). Antenna II as long as 0.48 antenna I. Peduncular article 5 slightly shorter than article 4, ratio between articles 4:5 equal to 1.25: 1, articles 4 and 5 with five and eight groups of simple setae, respectively. Flagellum with 10 articles, approximately 0.58 of length of peduncle articles 4 + 5.

Labium (fig. 11B) with inner lobes.

Maxilla I (fig. 10C & D). Inner plate with two long simple setae, outer plate with seven robust setae of which two with three, two with two, one with five, one with four and one without lateral projections; palp bi-articulated, long, with four long distal simple setae.

Maxilla II (fig. 10H). Both plates with numerous long distal simple setae, inner lobe with one lateral simple seta.

Mandibular palp (fig. 10G). Ratio of mandibular palp articles 1: 2: 3 equal to 1: 1.51: 1.88, no setae on first article; second article with six medial and two disto-lateral long simple setae. Distal article with one group of four A-setae, five groups of B-setae, no C-setae, 25 D-setae and five E-setae.

Left mandible (fig. 10F). Incisor with five teeth, lacinia mobilis with four teeth.

Right mandible (fig. 10E). Incisor with four teeth, lacinia mobilis pluritooth, seven setae with lateral projections between lacinia and triturative molar.

Maxilliped (fig. 11A). Inner plate short; distally three robust setae intermixed with three simple setae, subdistally one simple long lateral seta; outer plate exceeding half of posterior margin of palp article 2, with 11 marginal robust setae and six distal simple setae; palp article 3 at outer margin with one proximal, distal and medial group of long simple setae; distal article with five simple setae along outer margin, nail shorter than pedestal.

Gnathopod I (fig. 11C). Coxa of gnathopod I smaller than gnathopod II. Coxa I trapezoid, broader than long, ventral and anterior margins with one and six simple setae, respectively. Basis with long setae on anterior and posterior margins; ischium and merus with one posterior group of setae. Carpus with one group of setae anterodistally and many subdistal setae along anterior margin. Posterior part of carpus with setae on proximal bulbous and along postero-medial margin. Carpus 0.67 of basis length and 0.86 of propodus length. Propodus large, broader than long, posterior margin slightly convex. Anterior margin of propodus with 11 simple setae in two groups in addition to antero-distal group with six setae; palm slightly convex, with one strong long palmar robust seta, one short supporting robust seta on inner surface and two short robust setae with lateral projections on outer surface. In addition, two setae under supporting robust seta in palmar corner. Dactylus not reaching posterior margin of propodus, outer and inner margins each with a row of four simple setae, nail short, length 0.23 of total dactylus length.

Gnathopod II (fig. 11D). Coxa II rectangular, with 13 simple setae along antero-ventral margin. Posterior margin of basis with two groups of setae and two single setae, anterior margin of basis with single seta. Posterior margin of ischium and merus with one posterior group of setae. Carpus 0.49 of basis length and 0.84 propodus length; carpus with single antero-distal group of setae, with setae on posterior-proximal bulbous and with a row of setae along postero-medial margin. Propodus in gnathopod II larger than gnathopod I, broader than long, anterior margin with two simple setae in one group in addition to five antero-distal setae. Medial surface of propodus with few setae. Palm slightly convex, with one strong palmar robust seta, one short supporting robust seta on inner surface and two short robust setae with lateral projections on outer surface. Dactylus not reaching posterior margin of propodus, outer margin of dactylus with two groups of two and three simple setae, and with seven simple setae on inner margin, nail length 0.16 of total dactylus length.

Coxae III–VII (fig. 12A–F). Length to width ratio in coxa III 2: 1, antero-ventral margins of coxa III with 12 simple setae and one robust seta. Length to width ratio in coxa IV 1.12: 1, ventro- posterior margins of coxa IV with eight simple setae, posterior concavity shallow and approximately 0.07 of coxa width (fig. 12A–B). Coxa V with posteriorly developed lobe, with four simple setae in anterior lobe and four setae posteriorly. Coxa VI with anteriorly developed lobe, and single seta posteriorly. Coxa VII with one seta in posterior margin (fig. 12C–F).

FIGURE 10. Niphargus darvishi , sp. nov., Dimeh Spring, male 13 mm (holotype). A, A1; B, A2; C–D, MX 1; E, LMND; F, RMND; G, MNDP; H, MX 2. Scale bars: 1= 0.25 mm (E–F); 2= 0.5 mm (C–D, G–H); 3= 1mm (A–B).

FIGURE 11. Niphargus darvishi , sp. nov., Dimeh Spring, male 13 mm (holotype). A, MXP; B, L; C, GN 1; D, GN 2. Scale bars: 1= 0.5 mm (A–B); 2= 1mm (C–D).

Pereopods III–VII (fig. 12A–F). Pereopod III longer than IV with length ratio of 1.06: 1 (fig. 8A–B). Dactyli of pereopods III–IV short, simple seta along outer margin and with two robust setae and one simple setae at inner margin. Length of dactylus in pereopod IV 0.32 of propodus. Nail shorter than pedestal (fig. 12B).

Pereopods V–VII. Length ratios of perepods V: VI: VII equal to 1: 1.48: 1.51. Pereopod VII 0.52 of body length. Bases in pereopods V–VII with respective nine, six and six gropus of anterior setae and with 12, nine, and eight short single setae along posterior margin (fig. 12C–F). 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 margin. Propodus of pereopod VII slightly longer than these in V and VI. Dactyli of pereopods V–VII with three (on paratype, appendage broken in holotype), three and four robust setae along inner margin, respectively. Outer margin with single seta in pereopods V–VI and with two such setae in pereopod VII. Nail length of pereopod VII 0.28 of total dactylus length (fig. 12C–E).

Pereonites I–VII. No setae.

Pleonites I–III. With one simple seta at postero-dorsal margin.

Pleopods I–III (fig. 13A–C). Peduncle of pleopods I–III with two hooked retinacula at distal part of inner margin; peduncle of pleopods I–II each with one simple seta. Rami of pleopod I broken, Rami of pleopod II–III with 13–15 articles and 12–14 articles, respectively.

Epimeral plates I–III (fig. 13D). Epimeral plates with postero-ventral corner angular; posterior and ventral margins slightly convex. Epimeral plate III with distinctly produced posterodistal corner, posterior and ventral margins concave and convex, respectively. All plates with one long robust seta at posterior margin; with two, three and three simple setae at posterior margin, respectively; ventral margin of plates II and III with three and one robust setae, respectively.

Urosomites I–II. Postero-dorsally each with two robust setae. Dorsally with one and two simple setae, respectively. With one strong robust seta, at the base of uropod I.

Uropods I–III (fig. 13E–F). Peduncle in uropod I with five and three large robust setae in dorso-lateral and dorso-medial margins, respectively. Ratio of inner to outer ramus length 1.15: 1.05. Inner ramus with five groups of robust setae and five robust setae distally. Outer ramus with four groups of robust and simple setae laterally and five single robust setae distally (fig. 13E). Inner ramus in uropod II slightly longer than outer, both rami with lateral and distal long robust setae (fig. 13E). Uropod III with no sexual dimorphism, almost 0.24 of body length. Peduncle of uropod III with five robust setae distally, proximal article of outer ramus with five and six groups of robust setae along outer and inner margin, respectively (fig. 13F). Distal to proximal article ratio of outer ramus 1: 12, distal article with two simple lateral setae and one distal simple seta. Inner ramus of uropod III short, with one distal robust seta.

Telson (fig. 13G) as long as broad, deeply cleft, each lobe with three distal long robust setae and one long simple seta, with two simple setae laterally.

FIGURE 13. Niphargus darvishi , sp. nov., Dimeh Spring, male 13 mm (holotype). A, PL 1; B, PL 2; C, PL 3; D, EP 1–3; E, USM; F, U 3; G, T. Scale bars: 1= 0.5 mm (D, G); 2= 1mm (A–C, E); 3= 2mm (F).

Etymology. The species is named in honor of Professor Jamshid Darvish, Ferdowsi University of Mashhad who is one of the leading experts in animal biosystematics studies in Iran.

Remarks and affinities. Niphargus darvishi in many aspects (pectinate dactyli, produced epimeral plates and broad gnathopods) resembles to N. valachicus ; however, the two species differ from each other by ornamentation of urosomite I ( N. valachicus with single strong and curved seta on tiny protuberance) and male uropod I ( N. valachicus with finger-like protuberance distally on peduncle). Some similarities (pectinate dactyli, broad gnathopods) are found in species from West Balkan ( N. rejici , N. jadranko , N. pectencoronate , see Sket & Karaman 1990) and from Middle East ( N. nadarini , N. sertaci , N. khayyami see Alouf 1972; Karaman 1986; Fišer et al. 2009b; Hekmatara et al. 2013). Moreover, Middle East species share with N. darvishi another trait, i.e. pluritooth robust setae on outer lobe of maxilla I. None of these species, however, has disto-posteriorly produced epimeral plates or narrow bases of pereopods V–VII as herein described N. darvishi .

Figures

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