Paraschistura makranensis, Eagderi & Mousavi-Sabet & Freyhof, 2019

Eagderi, Soheil, Mousavi-Sabet, Hamed & Freyhof, Jörg, 2019, Paraschistura makranensis, a new loach from the Jegin River drainage in southern Iran with comments on P. ilamensis and P. pasatigris (Teleostei: Nemacheilidae), Zootaxa 4668 (2), pp. 258-270 : 261-263

Paraschistura makranensis , new species

( Fig. 2–8 )

Holotype. IMNRF-UT-1093-16, 33 mm SL; Iran: Hormuzgan prov.: Jegin River at Jegin , 26°09’43.1” N 57°53’30.0” E.

Paratypes. IMNRF-UT-1093, 2, 27–32 mm SL; IMNRF-UT-2093, 3, 26–30.4 mm SL; FSJF 3684 , 2 , 23–27 mm SL ; VMFC PM-P, 14, 27– 39 mm SL; same data as holotype .

Material for molecular genetic analysis. IMNRF-UT-2093- CO1-3, 3, same data as holotype; (Genbank accession numbers: MN 258033 , MN 258034 , MN 258035 ).

Diagnosis. Paraschistura makranensis is distinguished from all other Paraschistura species in Iran by a combination of characters, none of them unique. It is distinguished from its congeners in Iran except P. delvarii , P. turcmenica , and some populations of P. naumanni by having a plain brown or slightly mottled colour pattern on the flank (vs. flank with bars, at least on the caudal peduncle), and from all species except P. cristata by having a complete (vs. incomplete) lateral line.

It is further distinguished from P. bampurensis and P. cristata by having 7½ branched dorsal-fin rays (vs. usually 8½, rarely 7½ or 9½), and a shorter caudal fin (14–16% SL vs. 17–19% SL); from P. alta by presence (vs. absence) of a small and pointed processus dentiformis in the upper jaw, and an emarginate (vs. deeply forked) caudal fin. It is further distinguished from P. cristata by having a shallow dorsal adipose keel on the caudal peduncle without procurrent rays (vs. a prominent dorsal adipose crest supported by 22–25 procurrent rays) and presence (vs. absence) of a suborbital flap in males.

The new species is further distinguished from P. delvarii by presence (vs. absence) of a shallow dorsal adipose keel on the caudal peduncle, and absence (vs. presence) of flank scales anterior to the dorsal-fin origin. It is further distinguished from P. ilamensis , P. susiani and P. nielseni by absence (vs. presence) of scales on the back and flank anterior to the dorsal-fin origin.

Paraschistura makranensis is further distinguished from P. naumanni by having the pelvic-fin origin located posterior to the dorsal-fin origin (vs. pelvic-fin origin situated below or slightly anterior to the vertical through the dorsal-fin origin), and absence (vs. presence) of scales on the back and flank anterior to the dorsal-fin origin. It is further distinguished from P. kermanensis by presence (vs. absence) of a suborbital flap in males and having the pelvic-fin origin situated posterior to the vertical through the dorsal-fin origin (vs. in anterior to or below). It is further distinguished from P. kessleri , P. turcomana and P. turcmenica by presence (vs. absence) of caudal peduncle scales, and presence (vs. absence) of a suborbital flap in males.

Description. For general appearance, see Figures 2–6 . Morphometric data are provided in Table 3 . Small and slender species with relatively short head. Body deepest midway between nape and dorsal fin origin, depth decreasing slowly towards caudal-fin base. Greatest body width at centre of pectoral-fin base. Section of head roundish, flattened on ventral face. Caudal peduncle compressed laterally, 1.2–1.4 (mean 1.3) times longer than deep. Pectoral fin reaching approximately 50–65% of distance from pectoral-fin origin to pelvic-fin origin. Pelvic axillary lobe absent, or if present fully attached to body. Pelvic-fin origin below second or third branched dorsal-fin ray. Pelvic fin not reaching to anus. Anal-fin origin about one eye diameter posterior to anus. Anal-fin origin at vertical through mid-distance between dorsal- and caudal-fin origins. A shallow dorsal adipose keel without procurrent rays on caudal peduncle. Margin of dorsal fin straight or slightly convex. Caudal fin deeply emarginated. Largest known specimen 40 mm SL.

Dorsal fin with 7½ and anal fin with 5½ branched rays. Caudal fin with 8+8 branched rays. Pectoral fin with 9–10 (usually 9) and pelvic fin with 6–7 branched rays. Scales absent on back and flank anterior to dorsal-fin ori- gin. Only small, isolated, deeply-embedded scales on caudal peduncle. Lateral line complete, reaching to or almost touching caudal-fin base. Anterior nostril opening at tip of a pointed and flap-like tube. Nostrils separated by a narrow space, posterior tip of anterior nostril not overlapping posterior nostril when folded backwards. Male with a suborbital flap.

Mouth small, strongly arched ( Fig. 7 ). Lips moderately thick, with many deep furrows. A median interruption in lower lip. Upper lip with median incision. Processus dentiformis small and pointed. A shallow median notch in lower jaw. Barbels short, inner rostral barbel not reaching base of maxillary barbell, outer one reaching to or slightly beyond base of maxillary barbel, reaching vertical through anterior nostril. Maxillary barbel reaching vertical through distal part of eye.

Coloration. Body plain grey or pale brown, slightly mottled with yellow belly in life ( Fig. 6 ), yellowish in preserved individuals ( Figs. 4–5 ). Head dark-grey on top and side, cheek silvery cream. A prominent, irregularlyshaped, dark brown blotch at posterior extremity of caudal peduncle, notched or interrupted by 1–2 white streaks shortly above mid-height in some individuals. Dorsal and caudal fins hyaline, with elongated spots on rays. A prominent, usually large black, spot at base of unbranched dorsal-fin rays. Dorsal and caudal fins hyaline with faded black spots and stripes on rays, absent in some individuals. Pectoral, pelvic and anal fins hyaline.

Etymology. The species name makranensis refers to Makran, an ancient Persian word referencing the area along the coast of the Oman Sea. An adjective.

Distribution. Paraschistura makranensis is known from the upper Jegin River drainage ( Fig. 9 ).

Remarks. The descriptions of P. pasatigris ( Freyhof et al. 2015) and P. ilamensis ( Vatandoust & Eagderi 2015) were published almost simultaneously and both species occur in the same watershed. We were able to compare materials from both type localities as well as molecular characters (COI) of both species and found no differences between them. We therefore conclude that these two names represent a single species. To clarify the synonymy, the Principle of Priority (ICZN Article 23) is applied ( ICZN 1999). Paraschistura ilamensis became available online on 25 June 2015 with no mention of its online archiving in ZooBank, i.e., the online publication does not meet the criteria for archiving on ZooBank (despite it being archived on 25 June 2015 in Zenodo; https://zenodo.org/ record/845474#.XJ4EzdgyXIU). The description itself was printed and distributed on 30th June 2015, thus Para- schistura ilamensis is available only from this printed description ( ICZN 1999). The description of P. pasatigris was printed and distributed on 2nd July 2015 (F. Pfeil, pers. com), therefore P. ilamensis has two days’ priority over P. pasatigris and P. pasatigris has to be treated as a junior synonym of P. ilamensis .

Figures

FIGURE 2. Paraschistura makranensis, IMNRF-UT-1093-16, holotype, 32.7 mm SL; Iran: Jegin River.

FIGURE 3. Paraschistura makranensis, paratypes; a, IMNRF-UT-1093-15, 31.7 mm SL; b, IMNRF-UT-1093-17, 27.0 mm SL. Iran: Jegin River.

FIGURE 4. Paraschistura makranensis, VMFC PM-P, paratypes; from above: 35 mm SL; 35 mm SL; 34 mm SL; 34 mm SL; Iran: Jegin River.

FIGURE 5. Paraschistura makranensis, VMFC PM-P, paratypes; from above: 35 mm SL; 35 mm SL; 34 mm SL; 34 mm SL; Iran: Jegin River.

FIGURE 6. Paraschistura makranensis, VMFC PM-P 35.0 mm SL; Iran: Jegin River.

FIGURE 7. Paraschistura makranensis, IMNRF-UT-1093-15, paratype, 31.7 mm SL; Iran: Jegin River.

FIGURE 8. Paraschistura makranensis, showing suborbital flap; IMNRF-UT- 1093-15, paratype, 31.7 mm SL; Iran: Jegin River.

FIGURE 9. Type locality of Paraschistura makranensis: Jegin River near Jegin, Iran.