Paraschistura, Prokofiev, 2009

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 552-554

Paraschistura

Paraschistura is a poorly known group of medium-sized or small loaches, distributed from the Karkheh in Iran through- out southern Iran and Pakistan to the Indus and the Hari, Morghab, and Helmand in Afghanistan, Iran, Pakistan, and Turkmenistan. It is anticipated that some species of India’s large loach diversity may belong to this genus. The genus Paraschistura was first described in 2009, and 24 species are currently recognised, 16 of which are found in West Asia. The genus Metaschistura is a synonym. Several osteological characters diagnose Paraschistura . In Iran, all species except P. aredvii , P. nielseni , P. ilamensis , and P. susiani can be readily identified by a prominent black spot at the base of the first dorsal rays. The diversity of Paraschistura species in Iran has been well-studied, but knowledge of diversity in Afghanistan, Pakistan, and Turkmenistan is very poor. It is anticipated that further unidentified species will be discovered in these regions.

Further reading. Mirza et al. 1981 ( Pakistan); Prokofiev 2009 (description); Freyhof et al. 2015 (revision in West Asia, Metaschistura synonym, phylogeny).

Key to species of Paraschistura in Iran

1a - Body completely scaleless. ………………2

1b - Scales present at least on caudal peduncle; scales on flank and caudal peduncle often isolated and deeply embedded. ………………4

2a - Flank with marbled colour pattern without distinct bars or with bars dissociated in a row of midlateral blotches and saddles on back or with 11–14 irregularly shaped and set dark-brown bars on flank, usually dissociated into two adjacent narrow bars or individual bars with a central open space. ……………… P. turcmenica

2b - Flank with 10–12 regularly shaped and set, dark-brown bars. ………………3

3a - Body depth 11–15 % SL; pelvic origin below vertical of first branched dorsal ray; no dorsal adipose crest. ……………… P. kessleri

3b - Body depth 14–17 % SL; pelvic origin shortly before vertical of first branched dorsal ray; a short dorsal adipose crest. ……………… P. lindbergi

4a - Lateral line complete or almost complete, reaching to caudal base. ………………5

4b - Lateral line incomplete, reaching a point before caudal base. ………………7

5a - Caudal peduncle with a prominent dorsal adipose crest supported by 22–25 procurrent caudal rays; snout blunt. ……………… P. cristata

5b - Caudal peduncle without dorsal, adipose crest, if with crest, then without procurrent caudal rays; snout long and pointed. ………………6

6a - Processus dentiformis absent in upper jaw. ……………… P. alta

6b - Processus dentiformis in upper jaw small and pointed. ……………… P. makranensis

7a - Predorsal flank scaleless, scales present on caudal peduncle, also on back in populations from Sirjan and Jazmurian. ………………8

7b - Predorsal flank and back covered by scales. ………………9

8a - Pelvic origin situated behind vertical of dorsal origin. ……………… P. abdolii

8b - Pelvic origin situated in front of or below vertical of dorsal origin. ……………… P. kermanensis

9a - Suborbital flap or groove absent in male. ………………10

9b - Suborbital flap or groove present in male. ………………13

10a - Dorsal origin situated in front of vertical of pelvic origin. ……………… P. aredvii

10b - Dorsal origin situated above or very slightly behind of vertical of pelvic origin. ………………11

11a - Distance between anus and tip of pelvic 4–7 % SL. ……………… P. naumanni

11b - Distance between anus and tip of pelvic 7–10 % SL. ……………… P. delvarii

12a - Suborbital groove present in male. ……………… P. nielseni

12b –Suborbital flap present in male. ………………13

13a - Suborbital flap, triangular, not overlapping horizontal slit below flap; lateral line usually reaching beyond dorsal base; bold black spot at base of first dorsal rays; snout pointed. ………………14

13b - Suborbital flap roundish or elongate, overlapping slit below flap; lateral line not reaching or reaching to dorsal base; very faint black spot at base of first dorsal rays or spot absent; snout blunt. ………………15

14a - Flank with 11–18 dark-brown bars; pelvic reaching to about 1–2 eye diameter in front of anus. ……………… P. bampurensis

14b - Flank with 7–8 dark-brown bars; pelvic reaching to or beyond anus, to anal origin in some individuals. ……………… P. hormuzensis

15a - Male with an elongated suborbital flap pointed downward; caudal–peduncle depth 1.6–1.8 times longer than deep. ……………… P. ilamensis

15b - Male with a short, blunt, and roundish suborbital flap; caudal–peduncle depth 1.4–1.6 times longer than deep. ……………… P. susiani