Paraschistura delvarii spec . nov . – a new species of stone loach from the Persian Gulf basin , southern Iran ( Teleostei : Nemacheilidae )

Paraschistura delvarii, new species, from the Mond River drainage in the Persian Gulf basin, differs from other species of the genus in Iran by having a combination of the colour pattern consisting of marbled colour pattern without distinct bars on the flank, shallow and elongated body, incomplete lateral line extending to the dorsal-fin base, absence of dorsal adipose crest, bold black spot at base of first dorsal-fin rays, scatter scaled body, short and blunt snout, and suborbital groove in males.


Material and Methods
After anaesthesia, all fishes were fixed in 5% formal dehyde and stored in 70% ethanol.The morphological measurements were made by a dial caliper and recorded to the nearest 0.1 mm.All measurements were made point to point, never by projections.Methods for counts and measurements follow kottelat & freyhof (2007).Standard length (SL) was measured from the tip of the snout to the end of the hypural notch.The length of the caudal peduncle was measured from behind the base of the last anal-fin ray to the end of the hypural notch, at mid-height of the caudal-fin base.The last two branched rays articulating on a single pterygiophore in the dorsal and anal fins are noted as "1½".In the present study, the Paraschistura species from Afghanistan, Pakistan and Turkey are excluded from comparison as: (1) due to the wide geographical separation and morphological differ ences with regards to the congeners in southern Iran, (2) we had no access to the type specimens or type locali ties, and (3) based on original descriptions and available literatures (vatandoust & eagderi, 2015; freyhof et al., 2015) they are already superficially very different from the species discussed here.Also in Iranian endemic spe cies, P. susiani is compared based on original descrip tion.
Abbreviations used: SL, standard length; HL, lateral head length; GUIC, Collection of the Ichthyology Mu seum, Department of Fisheries Sciences, Faculty of Na tural Resources, the University of Guilan, Guilan prov ince, Iran; VMFC, Vatandoust and MousaviSabet Fish Col lection, Tehran.
Iran Colouration.In live specimens (Fig. 5) body is cream yellow above lateral line and becomes faint from lateral line to ventral surface, with dark to pale brown marbled pattern on flank and back, without distinct bars at least in the study specimens (less than 52.1 mm in total lenght).An obvious dark spot at the base of dorsal fin.A thick and obvious black bar at caudal-fin base.Upper part of  head, opercula and snout covered by dark brown small blotches.Dorsal and caudal fins with irregular dark spots, except distally so the fin margin is white.The lateral line is light, sometimes in marked contrast to the rest of the flank.In preserved specimens body is whitish with ir regular dark brown marbled pigmentation in dorsal and lateral parts.The belly is white, and all fins are hyaline (in preserved specimens).
Distribution.Paraschistura delvarii sp.nov., is known from upstream tributaries of Gharaghaj River, Mond River drainage, the Persian Gulf basin, in Fars province, south ern Iran.
Etymology.The species name delvarii is in honor of "Rais-Ali Delvari" (1882 -1915), the anti-colonialism in Bushehr province, the region where the Mond River drainage (type locality of P. delvarii) is located.RaisAli Delvari now remembered as the national hero of Iran.

Remarks
The presence of Paraschistura in the Persian Gulf basin was firstly reported by banarescu & nalbant (1966), who identified it, as Nemacheilus bampurensis (Para schi stura bampurensis).After that, nalbant & bianco (1998) separated the Paraschistura specimens from the Persian Gulf basin as distinct taxa and described them as a new species, Paraschistura nielseni.There are two main drainages in the Persian Gulf basin including Shapour Dalaki and Gharaghaj-Mond rivers.Paraschistura delva rii sp.nov., is described from GharaghajMond drainage, while P. nielseni is found in Shapur-Dalaki drainage.
Beside color pattern and elongated body, Para schi stura delvarii sp.nov., is distinguished from P. nielseni which is described from the same basin, by longer snout and barbels, and caudal fin with irregular dark spots (vs. 3 distinct rows).In the Mond River drainage, Oxynoemacheilus persa (Fig. 6) occurs in sympatry with