Capoeta aculeata (Valenciennes, 1844)

Freyhof, JÖrg, Yoğurtçuoğlu, Baran, Jouladeh-Roudbar, Arash & Kaya, Cüneyt, 2025, Handbook of Freshwater Fishes of West Asia, De Gruyter : 116-117

Capoeta aculeata

Common name. Largescale scraper.

Diagnosis. Distinguished from other species of Capoeta in Iranian Tigris and endorheic basins by: ● 36–44 total lateral-line scales / ○ 14–15 predorsal scales / ○ one pair of barbels / ○ flank beige, golden or brown without small black spots, juveniles and some adults with large black blotches / ○ last unbranched dorsal ray soft or moderately ossified, with small serrae / ○ usually 8½ branched dorsal rays / ○ 16–17 circumpeduncular scale rows / ○ 6–8, usually 7 scale rows between dorsal origin and lateral line / ○ 5–8, usually 6 scales between anal origin and lateral line / ○ 4–7, usually 5–6 scales between pelvic origin and lateral line / ○ 17–22 gill rakers / ○ 38–39 total vertebrae. Size up to 370 mm SL.

Distribution. Iran: Tigris drainage, endorheic Kor and Esfahan basins. Qom, Qareh Chai, Jaj, Khar, Ab-e Kamar drainages in Lake Namak basin. Hable, Nam and Bidvaz drainages in Western Kavir basin.

Habitat. Streams, rivers, and springs with moderately fastto slow-flowing water. From reservoirs, they migrate to rivers to spawn.

Biology. Feeds on detritus, periphyton, and occasionally small invertebrates.

Conservation status. LC.

Remarks. Capoeta aculeata had been described from Iran without details of type locality. Capoeta bergi , described from the Lake Namak basin, was treated as a synonym. Capoeta alborzensis was described from the Lake Namak basin based on the assumption that the type locality of C. aculeata is in Kor basin and C. bergi is not an available name. No type material of C. aculeata was examined for that study. Later research identified the populations from the Lake Namak basin as C. aculeata and treated C. gracilis from the Esfahan basin and C. macrolepis from the Tigris and endorheic Kor as valid species. Again no type material was examined. We consider C. aculeata , C. macrolepis , C. gracilis , C. bergi , and C. alborzensis as conspecific as they are very closely related, with an COI distance <1 %, and none of morphological characters proposed to distinguish them could be confirmed.

Further reading. Coad & Krupp 1994 (re-validation); Jouladeh-Roudbar et al. 2015b (distribution); Ghanavi et al. 2016 (phylogeny); Jouladeh-Roudbar et al. 2016a (description as C. alborzensis ); Zareian et al. 2017 (phylogeny, morphology); Jouladeh-Roudbar et al. 2020 (distribution as C. alborzensis ); Coad 2021a (biology, morphology).

Intrapopulation variation in mouth shape. In some, but not all, Capoeta species, there is a remarkable diversity of mouth shapes. In some individuals of the same size, the jaw is almost straight, while in others, it is horseshoe-shaped or strongly curved. These differences in mouth shape have been interpreted as sexual dimorphism. However, examination of a larger series has shown that mouth shape is unrelated to sex and that different mouth shapes occur at all ages and body sizes and reflect individual differences. The differences in mouth shape do not represent distinct morphs, and all intermediate mouth shapes are observed. Different mouth shapes may be related to ecological adaptations or feeding strategies that allow individuals within the same population to exploit a variety of food resources or habitats. However, this remains speculative and needs to be demonstrated by studying individual feeding behaviour, diet analysis and trophic signatures, such as stable isotopes.

Capoeta caelestis ; GÖksu drainage; Türkiye; wide- and narrow-mouth forms.

Capoeta anamisensis ; Minhab drainage, Iran; 120 mm SL.