Redescription of two subterranean amphipods Niphargusmolnari Mehely, 1927 and Niphargusgebhardti Schellenberg, 1934 (Amphipoda, Niphargidae) and their phylogenetic position Author Angyal, Dorottya Author Balazs, Gergely Author Zaksek, Valerija Author Krizsik, Virag Author Fiser, Cene text ZooKeys 2015 509 53 85 http://dx.doi.org/10.3897/zookeys.509.9820 journal article http://dx.doi.org/10.3897/zookeys.509.9820 1313-2970-509-53 E48C15FF9829447A93B23A8384DCADFF Taxon classification Animalia Amphipoda Niphargidae Niphargus molnari Mehely , 1927 Niphargus molnari sp. n.: Mehely 1927 type locality: Manfai-kolyuk Cave; Data from the original description is available in Suppl. material 3. Niphargus leopoliensis molnari : Schellenberg 1933 , samples from the Abaligeti Cave, morphological data. Niphargus molnari : Schellenberg 1935 , morphological data. Niphargus leopoliensis molnari , Niphargus molnari : Gebhardt 1933 , 1934 , 1963 , 1967 distributional data Niphargus molnari : Mehely 1941 additional morphological data. Niphargus molnari : Angyal and Balazs 2013 morphological and distributional data. Material examined for redescription. 7 females and 3 males from the stream of the Western 2. collateral of the Abaligeti Cave (Cadastre number: 4120-1, Hungarian Cave Cadastre), collected in 23 March 2013 (leg. D. Angyal and A. Illes ), dissected and mounted on slides; additional 4 specimens not dissected. Slides were deposited in the Collection of Crustaceans of the Hungarian Natural History Museum with the following codes: N.MOL-02, N.MOL-03, N.MOL-04, N.MOL-06, N.MOL-07, N.MOL-08, N.MOL-09, N.MOL-10, N.MOL-11, N.MOL-12. Diagnostic voucher number of specimen used for molecular studies: NB555 ( Niphargus molnari , coll. data: Abaligeti Cave, Western 2. collateral, stream, 23 March 2013, leg. D. Angyal & A. Illes ). COI Gen Bank Accession Number: KP967552 Diagnosis. Small to medium-sized niphargid; epimeral plate III postero-ventral corner sharply inclined. Telson with 3-4 apical spines, 1-3 lateral spines, 0-2 lateral plumose setae, 0-2 spines in cleft, dorsal surface with 1-3 spines in mediobasal position. Maxilla I outer lobe with 7 spines, 1.-3. pluri-toothed, 4.-7. variable (uni-, bi-, pluri-toothed). Gnathopod I and gnathopod II dactyli with single seta on outer margin. Gills II-VI ovoid, approximately same size as pereopod VI coxa, posterior margin slightly concave. Pleopods I-III with 2 retinacles on each. Uropod I lenght of endopodite: length of exopodite ratio as 1.00: (1.00-1.20) on males and 1.00: (1.15-1.18) on females. Uropod III sexually dimorphic, exopodite rod-shaped, distal article of exopodite on males 83-115% of proximal article length and 18-73% on females. Description. Body and telson. Small to medium-sized species, females are 6.4 mm to 9.0 mm, males are 7.8 mm to 10.6 mm. Head length up to 13% of body length; rostrum absent. Pereonites I-VI without setae; pereonite V, VI, VII with 1 postero-ventral seta each. Pleonites I-III with 3-6 setae along dorso-posterior margin (Fig. 3). Epimeral plate II ventral and posterior margins straight or sinusoid, ventro-postero-distal corner approximately perpendicular and pointed; along ventral margin 1-3 spiniform setae; along posterior margin 4-6 thin setae (Figs 3, 4). Epimeral plate III ventral margin convex and posterior margin straight, ventropostero-distal corner sharply inclined, strongly produced; along ventral margin 2-3 spiniform setae; along posterior margin 4-6 thin setae (Figs 3, 4). Urosomite I postero-dorso-laterally with 1-2 spiniform seta; urosomite II postero-dorso-laterally with 2-3 spiniform setae; urosomite III without setae. Near insertion of uropod I 1 spiniform seta (Fig. 3). Figure 3. Niphargus molnari , male from the Abaligeti Cave, lateral view. Telson, mouthparts and pleopods II-III are not drawn. Telson length: width as 1.0: 0.6-0.8; cleft 71-87% of length; lobes apically rounded. Telson spines (per lobe): 3-4 apical spines; lateral margins with 1-3 spine, 0-2 plumose setae; 0-2 in cleft spines, dorsal surface with 1-3 basal spines in mediobasal position (Figs 4, 9). Length of apical spines 20-25% of telson length. Figure 4. Niphargus molnari , scanning electron micrographs. A epimeral plates (Ep1-3 = epimeral plates 1-3) B honeybee-cell pattern on the exosceleton (tipical feature of amphipods) C pleopod with two retinacles (pl-r = pleopod ramus, ret = retinaculum) D retinaculi on the pleopod (ret = retinaculum) E gnathopod II propodus (prop = propodus, sup-spine = supporting spine, dact = dactylus) F palmar region of gnathopod II propodus (dent-spine = denticulated spine, sup-spine = supporting spine, n = nail, palm-spine = palmar spine). Antennae and mouthparts. Antenna I 35-48% of body length. Flagellum with up to 19 articles; each article with 1 long aesthetasc. Peduncle article 1: 2: 3 proportions 1.0 : 0,78 (0.72-0.88): 0,4 (0.36-0.46). Proximal article of peduncle dorso-distally slightly produced. Accessory flagellum biarticulated; distal article shorter than one-half of the proximal article. Lengths of antennae I: II as 1.0: 0.50. Flagellum of antenna II with 6-8 articles. Lengths of peduncle articles 4: 5 as 1.0: (0.84-0.95); flagellum 54-70% of peduncle length (articles 4 + 5) (Fig. 5). Figure 5. Niphargus molnari , aI = antenna I, aII = antenna II, mxI = maxillaI, mxII = maxilla II, md-R = right mandibula, lm = lacinia mobilis, inc = incisor, md-L = left mandibula, lb = labium, mxpe: maxilliped. Inner lobes of labium longer than half of outer lobes (Fig. 5). Left mandible: incisor with 5 teeth, lacinia mobilis with 4 teeth; between lacinia and molar 6-9 thick, serrated setae, long seta at base of molar absent (Fig. 5). Right mandible: incisor processus with 4-5 teeth, lacinia mobilis with several small denticles (more then 12), between lacinia and molar 6-7 thick, serrated setae, long seta at base of molar present. Proportions of mandibular palp articles 2: 3 (distal) as 1.0: 1,20 (1.17-1.32). Proximal palp article without setae; second article with 9-11 seta in 5-6 groups; distal article with 1 group of 3-5 'A setae' ; 3 groups of 'B setae' ; 16-24 'D setae' ; 3-5 'E setae' (Fig. 5). Maxilla I distal palp article with 2-3 apical and subapical setae. Outer lobe of maxilla I with 7 spines, 1-3 spines are always pluri-toothed with 3-6 lateral tooth while 4-6 spines are uni-, or bitoothed. Inner lobe with 1-2 setae (Fig. 5). Maxilla II inner lobe slightly smaller than outer lobe; both of them setose apically and subapically, number of setae is approximately 13-23 per lobe (Fig. 5). Maxilliped palp article 2 with 11-17 rows of setae along inner margin; distal article with dorsal seta and group of small setae at base of nail. Maxilliped outer lobe with 6-12 flattened, thick setae and 3-8 serrated setae; inner lobe with 2-3 flattened, thick setae apically and 5-9 serrated setae (Fig. 5). Coxal plates. Coxal plate I width: depth as 1.00: 1.03 (0.89-1.16), of flattened rhomboid shape, antero-ventral corner subrounded; anterior and ventral margin of coxa I with 3-6 setae (Fig. 6). Coxal plate II width: depth as 1.00: 0.84 (0.76-0.95); anterior and ventral margin with 5-8 setae. Coxal plate III width: depth as 1.00: 0.82 (0.71-1.00); along antero-ventral margin 4-7 setae (Fig. 7). Coxal plate IV width: depth as 1.00: 1.03 (1.26-0.88); posteriorly concave; along antero-ventral margin 5-7 setae (Fig. 7). Coxal plates V-VI: anterior lobe well developed; along posterior margin 1 seta (Fig. 7). Coxal plate VII half-egg shaped, along posterior margin 1 seta (Fig. 7). Gills II-VI ovoid, with approximately same size as coxa VI (Fig. 7). Figure 6. Niphargus molnari , gpI = gnathopod I, gpII = gnathopod II. Figure 7. Niphargus molnari , ppIII = pereopod III, ppIV = pereopod IV, ppV = pereopod V, g = gill, oost = oostegit. Gnathopods. Basis width is 38 (33-45)% of basis length. Gnathopod I ischium with 4-8 posterodistal setae in 1 row. Carpus length 62 (57-75)% of basis length and 87 (80-100)% of propodus length. Anterior margin of carpus only with distal group of setae; carpus posteriorly with transverse rows of setae proximally and a row of lateral setae, posterior enlargment small. Propodus subquadrate, palm convex. Along posterior margin 6-8 rows of denticulated setae. Anterior margin with 10-17 setae in 2-3 groups, antero-distal group with 6-12 setae. Group of 2-4 facial setae below (proximal of) palmar spine; 2-4 single surface setae present. Palmar corner with palmar spine, single supporting spine on inner surface, and 3 (rarely 4) denticulated, thick spiniform setae on outer side. Nail length 36 (34-37)% of total dactylus length; along anterior margin single seta; along inner margin 4-5 setae (Fig. 6). Gnathopod II basis width: length as 1.0: 0.26 (0.21-0.29). Ischium with 2-6 postero-distal setae. Carpus length 56 (50-61)% of basis length and 86 (71-94)% of propodus lenght. Anterior margin of carpus only with distal row of setae; carpus posteriorly with transverse rows of setae proximally, a row of lateral setae; postero-proximal bulge small, positioned proximally. Propodus medium-sized (sum of length, diagonal and palm length measures up to 19 (15-21)% of body length) and larger than propodus of gnathopod I (1.0: 0.57 (0.65-0.85)). Propodus rectangular, palm convex. Posterior margin convex with 6-9 rows of denticulated setae. Anterior margin with 10-20 setae in 3-5 groups; antero-distal group with 7-9 setae. 1 group of 2-3 facial setae below (distal of) palmar spine; 1-4 individual surface setae present. Palmar corner with strong palmar spine, single supporting spine on inner surface, and 1 denticulated, thick spiniform seta on outer side. Nail length 31 (22-36)% of total dactylus length. Along anterior margin single seta; along inner margin 4-6 short setae (Figs 4, 6). Pereopods III-IV. Proportions of pereopods III: IV as 1: 0.95 (0.93-0.97). Dactylus IV 45 (39-51)% of propodus IV; nail length 47 (39-52)% of total dactylus length. Dactyli III-IV with one dorsal plumose seta, one spine-like seta at the base of the nail, and tiny seta near the spine-like seta (sometimes not visible or absent). Additional spiniform setae on posterior margin are absent (Fig. 7). Pereopods V-VII. Proportions of pereopods V: VI: VII as 1.00: 1.4 (1.37-1.54): 1.5 (1.42-1.61). Pereopod VII length 47 (42-52)% of body length. Basis V-VII narrow with convex posterior margins. Basis V width is 70 (60-78)% of length, basis VI is 67 (59-76)% of length and basis VII is 66 (56-76)% of length. Basis V with small posterodistal lobe, posterior margin with 8-13 setae, anterior margin with 6 -8 groups of setae. Dactylus V with one dorsal plumose seta, one spine-like seta at the base of the nail, and tiny seta near the spine-like seta (sometimes not visible or absent). Additional spiniform setae on posterior margin are absent (Fig. 7). Basis VI with small posteriodistal lobe, posterior margin with 9-14 setae, anterior margin with 6-10 setae. Dactylus VI with one dorsal plumose seta (sometimes not visible or absent), one spine-like seta at the base of the nail, and tiny seta near the spine-like seta (sometimes not visible or absent). Additional spiniform setae on posterior margin are absent (Fig. 8). Figure 8. Niphargus molnari , ppVI = pereopod VI, ppVII = pereopod VII, plpII = pleopod II. Basis VII posterior margin with 6-13 setae, anterior margin with 6-11 groups of setae. Total number of basis setae is 15-21. Dactylus VII length 26 (24-29)% of propodus VII length; nail length 26 (16-33)% of total dactylus length. Dactylus VII with one spine-like seta at the base of the nail. Additional spiniform setae on posterior margin are absent (Fig. 8). Pleopods. Pleopods I-III with 2-hooked retinacles. Pleopod II rami of 16-20 articles each (Figs 4, 8). Uropods. Uropod I basipodite with 6 dorso-lateral and 6 dorsomedial spinifom setae. Length ratio endopodite: exopodite as 1.00: 0.89 (0.83-1.0); rami slightly curved. Endopodite total setae number 2-4 in 2-3 groups, apically 5 spinifom setae. Exopodite with 2-7 spines; apically 5 spinifom setae (Fig. 9). Figure 9. Niphargus molnari , t = telson, upI = uropod I, upII = uropod II, upIII-f = female's uropod III, upIII-m = male's uropod III. Uropod II endopodite: exopodite length as 1.00: 0.81 (0.77-0.9) (Fig. 9). Uropod III up to 38-46% (males) and 12-42% (females) of body length. Basipodite with no lateral seta and 3-6 apical spiniform and thin setae. Endopodite 58-61% (males) and 48-70% (females) of basipodite length, endopodite apically with 1-2 thin-flexible and spiniform setae; laterally 0-1 seta. Exopodite of uropod III rod-shaped, distal article of exopodite 83-115% (males) and 18-73% (females) of proximal exopodite article length. Proximal article with 4-5 groups of plumose, thin-flexible and spiniform setae along inner margin and 4 groups of thin-flexible and spiniform setae along outer margin. Distal article with 3-6 apical setae; lateral setae only in males (Fig. 9).