NIPHARGUS CYMBALUS, NEW SPECIES AND N. JOVANOVICI S. KAR. 1931 IN GREECE (CONTRIBUTION TO THE KNOWLEDGE OF THE AMPHIPODA 298)

Two members of the family Niphargidae (Amphipoda, Gammaridea) from Greece are treated in this study: From the subterranean waters in Epirus is described and figured new species Niphargus cymbalus, sp. n. [type locality: wells in Glikorizo, Epirus, Greece] and its taxonomic position regarding other members of this genus are discussed. Niphargus jovanovici S. Karaman, 1931 [loc. typ.: Skoplje, Macedonia] is established at the first time from two localities of Greece [Viotica in Attica and Amarinthos on Euboea island] and taxonomical characteristics of these populations regarding these from Macedonia are analyzed.


INTRODUCTION
The subterranean fauna of Amphipoda in Greece is very rich but only partially investigated, presented by several families and genera with various number of species.Among the family Niphargidae, genus Niphargus Schiödte 1849, was presented by nearly 16+ species known from continental Greece and Greek islands (G.Karaman, 2017).During our recent studies of Niphargus samples collected by Italian scientists in Greece, we established one new species from the subterranean waters in Epirus region, Niphargus cymbalus, sp.n. and presence of Niphargus jovanovici S. Karaman 1931 known from Macedonia, in two localities in Greece.

MATERIAL AND METHODS
The studies material was preserved in the 70% ethanol.The specimens were dissected using a WILD M20 microscope and drawn using camera lucida attachment.All appendages were temporarily submersed in the mixture of glycerine and water for study and drawing.Later, all appendages have been transferred into Liquid of Faure on permanent slides.The body-length of examined specimens were measured by tracing individual's mid-trunk lengths (from tip of head to end of telson) using camera lucida.All illustrations were inked manually.Some morphological terminology and setae formulae follow G. Karaman's terminology (Karaman, G. 1969;2012) regarding the last mandibular palpus article [A= setae on outer face; B= setae on inner face; C= additional setae on outer face; D= lateral marginal setae; E= distal long setae] and propodus of gnathopods 1 and 2 [S= corner S-spine on outer face; L= lateral slender serrate Lspines; M= facial M-setae; R= subcorner R-spine on inner face].Terms "setae" and "spines" are used based on its shape, not origin.The study was realizes based on morphological, ecological and zoogeographical research.
Maxilla 2 is with well developed lobes bearing numerous distal marginal setae each, facial setae absent (fig.5C).
Coxa 7 is entire, broader than long (ratio: 57:25) (fig.4E).Gnathopods 1 and 2 are relatively small, nearly as large as corresponding coxa (fig.2A, D).Gnathopod 1: article 2 along proximal part of anterior and posterior margin, with rows of long setae, in distal part is with shorter setae (fig.2A); article 3 at posterior margin with one bunch of setae; article 5 is slightly shorter than propodus (ratio: 42:49), along anterior margin with distal bunch of setae, along posterior margin with numerous long setae.Propodus trapezoid, slightly longer than broad (ratio: 83:75), along posterior slightly inclined margin appear 5 transverse rows of setae (fig.2B); palm is slightly convex, inclined rather less than half of propodus-length, defined on outer face by one corner Sspine accompanied laterally by 2 serrate L-spines and with 2 facial M-setae, on inner face appear one subcorner R-spine (fig.2C).Dactylus reaching posterior margin of propodus, along outer margin are attaches 4 single median setae (fig.2B), at inner margin appear several short setae.
Gnathopod 2 is distinctly larger than gnathopod 1 (fig.2D).Article 2 is in proximal part with long setae and in distal part with shorter setae; article 3 at posterior margin with one bunch of 2 median setae; article 5 is slightly shorter than propodus (ratio: 48:60), along anterior margin with one bunch of distal setae, along posterior margin with numerous setae.Propodus is trapezoid, poorly longer than broad (ratio: 100:94), along posterior margin with 7 transverse rows of setae (fig.2E); palm slightly convex, inclined nearly 1/3 of propodus-length, defined on outer face by one corner S-spine accompanied laterally by 2 L-spines and 2 long facial M-setae, on inner face by one subcorner R-spine (fig.2F).Dactylus reaching posterior margin of propodus, along outer margin are attached 4 single median setae, along inner margin appear several short setae.
Pereopods 3 and 4 are relatively slender.Pereopod 3: along anterior slightly concave margin of article 2 appear 2 long setae in proximal part and 2-3 short setae in distal part, along posterior margin are attached 2 proximal long setae and several short setae (fig.3A).Articles 4-6 are of different length (ratio: 60:40:50), articles 4 and 5 along both margins with single spine-like setae; article 6 along posterior margin with 4 single short spines, at tip with one long and 2 short setae.Dactylus is much shorter than article 6 (ratio: 24:50), at inner margin with one weak spine, at outer margin with one median plumose seta; nail is shorter than pedestal (ratio: 30:45) (fig.3B).
Pereopod 4: article 2 with long setae in proximal part and short setae in distal part; articles 4-6 of different length (ratio: 54:40:47); articles 4-5 along both margins with short setae and spine-like setae; article 6 at posterior margin with 4 groups of single short spines and setae (fig.3C).Dactylus is much shorter than article 6 (ratio: 21:47), at inner margin with one slender spine near basis of the nail, along outer margin with one median plumose seta; nail is shorter than pedestal (ratio: 30:36) (fig.3D).
Uropod 1: peduncle with dorsoexternal and dorsointernal row of strong spines (fig.5H); inner and outer ramus are of equal length; inner ramus is with 4 lateral and 3-4 distal strong short spines; outer ramus is with nearly 6 lateral short spines and distal bunch of 4 short spines.
Uropod 2: peduncle is with 2 distal strong spines; outer and inner ramus are of equal length; outer ramus is poorly curved upwards, bearing one lateral and 4 distal short spines; inner ramus is straight, bearing 2 lateral and 4 distal short spines (fig 5H).Uropod 3 unknown [based on the taxonomic characteristics of the body, we suppose that uropod 3 should be short and strong, with short distal article of outer ramus].
Telson is not elongated, slightly longer than broad (ratio: 85:74), incised over ¾ of telson-length; each lobe is provided with 3 distal spines (the longest spine reaching half of telson-length), lateral and facial spines are absent; one short plumose seta is attached at external distal tip of each lobe (fig.1J).One pair of 2 unequally long plumose setae is attached along outer margin nearly the middle of each lobe.

REMARKS AND AFFINITIES
Niphargus cymbalus differs from all known species of genus Niphargus known from Greece by very large ovoid basipodit of pereopods 5-7, but this character is present in various other species from adjacent regions.
At the first glance, N. cymbalus is rather similar to Niphargus lourensis Fišer et al. 2006, described from Greece (loc.typ.: spring of Louros River) by short uropod 3, absence of lateral and facial spines on telson, shape of gnathopods), but N. lourensis differs by much more narrowed basipodit of pereopods 5-7, higher number of setae on maxilla 1 inner plate, etc.
By the shape of basipodit of pereopods 5-7, lobate coxa 4, acute epimeral plates and almost pectinate outer plate spines of maxilla 1, N. cymbalus is rather similar to Niphargus skopljensis S. Karaman, 1929, known from Macedonia [loc.typ.subterranean waters in Skoplje], but N. skopljensis differs remarkably from N. cymbalus by presence of only one median seta on dactyls of gnathopods 1 and 2, by fully pectinate outer plate spines of maxilla 1, by different shape of propodus of gnathopods 1 and 2, etc.
Another species with very large ovoid lobed basipodit of gnathopods 1-2 is Niphargus factor Karaman & Sket, 1990 known from Bosnia and Herzegovina [loc.typ.: Vjetrenica cave near Trebinje], but this species differs from N. cymbalus by very long and slender dactylus of all pereopods, long and narrow telson, narrow propodus of gnathopods 1-2, etc.
To this group belongs also Niphargus hebereri Schellenberg 1933 described from Croatia [loc.typ.: wells in Rovinj, Istra], species very similar to N. cymbalus by various characters (epimeral plates, pereopods, maxilla 1), but this species differs from later by different shape of propodus in gnathopods 1-2, by longer and narrow telson, unequal rami of uropod 2, etc.
DERIVATIO NOMINIS.The name cymbalus regards the association of broad pereopods of this species with the musical percussion instrument cymbal.

REMARKS.
Niphargus jovanovici has been discovered and described by S. Karaman in 1929 from the wells in Skoplje, and later was mentioned by some authors from various other localities in Macedonia only.Pesce & Maggi (1983) generally mentioned N. jovanovici for Ionian islands and northern Greece, but without any locality or description.
Among the studied samples of Niphargus collected by various samplers from Greece, we established the presence of N. jovanovici in samples from Amarinthos and Levadia.Taxonomic characters of these specimens agree mainly with these from Macedonia.
Urosomal segment 1 on each dorsolateral side with 1 seta, urosomal segment 2 on each dorsolateral side with one slender spine, urosomal segment 3 naked.
Maxilliped inner plate short, with 2 distal spines and single setae, outer plate short, with 6 distolateral (mesial) pointed spines, palpus article 4 with one seta at inner margin near basis of the nail.
Propodus of gnathopods 1 and 2 is ovoid, that of gnathopod 1 is hardly longer than propodus of gnathopod 2 (fig.5 I, J).Palm of gnathopod 1 propodus is with convex margin bearing on outer face one corner S-spine accompanied by one lateral L-spine and 3 facial M-setae, on inner face appear one longer R-spine.Palm of gnathopod 2 propodus is on outer face with one S spine accompanied laterally by one L-spine and 2 facial M-setae, on inner face by one longer Rspine (fig.6A).Dactylus of gnathopods 1-2 is with 2-3 short outer marginal median setae (fig.5 I, J).
Uropod 1 peduncle is provided with dorsointernal and dorsoexternal row of spines.Rami of uropod 1 are of equal length, with several lateral spines and long distal spines (fig.6E).
Uropod 2 is with equal rami bearing long distal spines (the longest spines are almost as long as rami themselves) (fig.6F).
Uropod 3 is relatively short, with inner ramus scale-like bearing distal spine and plumose seta; outer ramus 2-articulated: first article along outer margin with 4 bunches of spines, along inner (mesial) margin with 4 bunches of longer slender spines mixed with single plumose setae (fig.6G); second auricle is short, without plumose setae or spines.
Telson is slightly longer than broad (ratio: 54:45), incised only slightly over half of telson-length; each lobe is provided with 2 slender distal spines and one short plumose seta, accompanied laterally by 3 very long plumose setae (fig.6H).
Specimen from Viotia (juv.5.5 mm) agree with specimen from Amarynthos, but propodus of gnathopod 1 is hardly more narrow than that of gnathopod 2, with dactylus bearing 1-2 short median setae along outer margin.Distal spines on rami of uropods 1 and 2 are rather longer than these in specimen from Amarinthos.

VARIABILITY
Dactylus of gnathopods 1-2 in specimens of N. jovanovici from Macedonia is provided usually with one median seta only, but the specimen from spring near Kumanovska reka-River is provided with 1-2 median setae along outer margin.Evidently, this character is rather variable within N. jovanovici.
The length of distal spines on rami on uropods 1 and 2 is also rather variable within specimens from various localities in Macedonia and Greece.

CONCLUSIONS
Based on present research, the number of known species of genus Niphargus is elevated to 17+ species.
It was very useful attempt to divide large amount of Niphargus species (now over 300 taxa) into smaller entities based on certain morphological characters.The further study of these taxa based also on other characters, will clear taxonomical position of all these species to each other and within genus Niphargus.