Cobitis

Mousavi-Sabet, Hamed, Vatandoust, Saber, Esmaeili, Hamid Reza, Geiger, Matthias F. & Freyhof, Jörg, 2015, Cobitis avicennae, a new species of spined loach from the Tigris River drainage (Teleostei: Cobitidae), Zootaxa 3914 (5), pp. 558-568 : 558-568

Key to species of Cobitis in the Caspian Sea and Tigris basins

1a – Z4 consisting of indistinct minute dark grey roundish dots............................................... C. kellei

1b – Z4 consisting of distinct, large dark blotches, usually horizontally elongated on anterior body, roundish or vertically elongated on caudal peduncle.................................................................................... 2

2a – Two large, roundish black spots on upper and lower caudal-fin base.................................. C. melanoleuca

2b – No spot or one black spot on upper caudal-fin base........................................................... 3

3a – One large, roundish black spot on upper caudal-fin base............................................... C. keyvani

3b – No spot or a small, usually comma-shaped black spot on upper caudal-fin base..................................... 4

4a – Subdorsal scales with a large focal zone (about ½ of maximum scale diameter)..................................... 5

4b – Subdorsal scales with a small focal zone (about or less than 1/10 of maximum scale diameter).......................... 6

5a – Very small black spot on upper caudal-fin base, usually absent........................................ C. amphilekta

5b – Small, usually comma shaped black spot on upper caudal-fin base......................................... C. taenia

6a – Z4 consisting of 12–17 dark-brown blotches; individuals larger than 65 mm SL with 5–6 rows of dark spots on dorsal and caudal fins.................................................................................... C. avicennae

6b – Z4 consisting of 20–30 dark-brown blotches; individuals larger than 65 mm SL with 3–4 rows of dark spots on dorsal and caudal fins..................................................................................... C. faridpaki