Tariqilabeo iranicus, Esmaeili & Sayyadzadeh & Masoumi & Hashemi & Echreshavi, 2025

Tariqilabeo iranicus , new species urn:lsid:zoobank.org:act:03F19EB4-780E-4D94-A646-212CBC59B043

( Figs. 2–7 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 )

Holotype. ZM-CBSU TQ007 , 71 mm SL; Iran: Hormuzgan Province: Jask city, Jagin River, Makran basin , 25°45’ 35.31”N, 58°12’ 9.28”E; Esmaeili, Hashemi, Masoumi, Echreshavi, Karami & Abbasi, 04 March 2024. GoogleMaps

Paratypes. ZM-CBSU TQ008 , 13, 34–68 mm SL; same as holotype. GoogleMaps ZM-CBSU TQ001 , 6, 27–36 mm SL; Iran: Hormuzgan Province: Jask city, Gabrik River, Makran basin , 25°46’19.27”N, 58°28’1.09”E.; Esmaeili, Hashemi, Masoumi, Echreshavi, Karami & Abbasi, 04 March 2024 GoogleMaps .

Material used in molecular genetic analysis. All from Iran, Hormuzgan province. ZM-CBSU M3752 , M3775 , M3776 ; Jask city, Gabrik River, Makran basin, 25°46’19.27”N, 58°28’1.09”E. (GenBank accession numbers: SUB15140466 ZM_CBSU3752 PV197641 ; SUB15140466 ZM_CBSU3775 PV197642 ; SUB15140466 ZM_CBSU3776 PV197643 ). GoogleMaps ZM_CBSU M3657 ; Nikshahr, Nikshahr River, Makran basin , 26°16’ 53.99”N, 60°10’ 27.84”E (GenBank accession numbers: SUB15140466 ZM_CBSU3657 PV197644 ) GoogleMaps .

Diagnosis. Tariqilabeo iranicus sp. nov. is superficially similar to its closest congener, T. diplochilus , but can be distinguished by having a silvery spot on the operculum (vs. absent), snout shorter than postorbital length (vs. longer) [snout/postorbital length ratio: 36.6–44.9/41.6–49.8 % SL vs. 39.4–45.9/38.2–44.7% SL, and a K2P nearest neighbor distance of 4% in the COI barcode region. Tariqilabeo iranicus sp. nov. is distinguished from T. latius by having 22–24 gill rakers on first arch (vs. 37–39) [data based on Talwar & Jhingran 1991, and Sayyadzadeh et al. 2015] and 34–36 lateral-line scales (vs. 39–41) [data based on Talwar & Jhingran 1991, and Sayyadzadeh et al. 2015]; from T. adiscus by having 2 pairs of shorter barbels (rostral barbel: 10.0–11.5% HL vs. 12.2–16.8% HL; maxillary barbel 3.8–4.5% HL vs. 5.6–10.5% HL), 22–24 gill rakers on first arch (vs. 19–22), and 2–3 scales between anus and anal fin (vs. 3–5); from T. periyarensis by having 22–24 gill rakers on first arch (vs. 15–17) and absence of horny tubercles on snout and cheek in males (vs. presence) [data based on Menon & Jacob 1996: figs. 1–3]; from T. burmanicus by having 22–24 gill rakers on first arch (vs. 50–53) [data based on Talwar & Jhingran 1991], 12–14 circumpeduncular scale rows (vs. 16) [data based on Ciccotto & Page 2016]; 34–36 lateral-line scales (vs. 35–38) [data based on Ciccotto & Page 2016]; and presence of maxillary barbels (vs. absence) [data based on Talwar & Jhingran 1991, and Jayaram 1999]; from T. wattanah by having 22–24 gill rakers on first arch (vs. 20–24), presence of midlateral stripe (vs. absence) and absence of tubercles on head (vs. presence, occasionally extending onto humeral, breast, and predorsal regions) [data based on Ciccotto & Page 2016: figs. 8,11]; from T. macmahoni by having (vs. lacking) fringes on rostral fold [data based on Ciccotto & Page 2016]; and from T. bicornis by having 2–3 scales between anus and anal-fin origin (vs. 4–5), 12–14 circumpeduncular scale rows (vs. 16); and absence of rostral flap on snout (vs. presence) [data based on Zhang & Kottelat 2006, and Ciccotto & Page 2016].

Description. For general appearance see Figures 2–7 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 . Morphometric data are provided in Table 3 View TABLE 3 . Body elongated, compressed laterally along caudal peduncle. Dorsal head profile rising gently, slightly convex, more or less continuous with dorsal body profile. Ventral profile more or less straight up to anal-fin origin. Head small, flat, compressed, with slightly convex or flat interorbital region. Snout prominent, rounded, shorter than postorbital length. No rostral flaps on tip of snout. Eyes positioned dorsolaterally on anterior half of head. Nostril nearer to eye than to tip of snout. Rostral cap well-developed with fimbriae superficial on upper jaw and covering upper lip. Mouth inferior and wide, its opening slightly arched; upper lip very thin with no papillae, widening at corner of mouth connecting upper jaw to lower jaw; lower lip free on anterior and lateral edges, anterior edge with papillae; posterior edge connected to underside of head with no modified mental disc), horny jaw sheaths thin. Sublachrymal groove uniformly narrow from corner of mouth to rostral barbel, not expanding anteriorly to make rostral lobe. Barbels in two pairs; rostral barbel anterolaterally located, thicker at the base and shorter than eye diameter [rostral barbel: 10–11.5% HL, maxillary barbel 3.8–4.5% HL vs. eye diameter 21–25% HL]; maxillary barbel at corner of mouth, shorter than rostral barbel.

Dorsal fin with 3 unbranched and 8½ branched rays; distal margin concave; origin closer to snout tip than to caudal-fin base, inserted anterior to vertical through pelvic-fin origin; first branched ray longest, tip of last branched ray extending vertically to or slightly in front of anus when adpressed. Pectoral fin with 14–16 rays, reaching to 3–4 scales anterior to pelvic-fin origin, its length shorter than head length. Pelvic fin with 9 rays, reaching to anus; origin closer to anal-fin origin than to pectoral-fin origin, inserted below base of third or fourth branched dorsal-fin ray. Anal fin short, with 3 simple and 5½ branched rays; first branched ray longest; distal margin straight or slightly concave; origin slightly closer to pelvic-fin origin than to caudal-fin base. Caudal fin forked with 9+8 branched rays; tip of lobes pointed. Total gill rakers on first branchial arch 22–24. Lateral line complete, with 34–36 scales. Transverse scale rows above lateral line 3½–4½; between lateral line and pelvic-fin origin 3½–4½ and between lateral line and anal-fin origin 3½–4½. Circumpeduncular scale rows 12–14. Predorsal scales 11–14. Anus positioned 2–3 scales in front of anal-fin origin. Scales between posteriormost pelvic-fin base and anus 7–8. Scales on flank regularly arranged. Scales on chest and abdomen smaller than flank scales.

Coloration: In 70% ethanol: dorsal half of body olive green to dark brown; lighter in small specimens. Most specimens with dark brown stripe on midline of dorsum. A dark brown stripe on midline of flank, more distinct in juvenile specimens. Belly whitish or pale grey. Dorsal surface of head dark brown; cheeks and ventral surface of head whitish, lateral portions of head above cheek yellowish with brown spots. A silvery spot on operculum, more distinct in small specimens (<50 mm SL) [ Fig. 6 View FIGURE 6 ]. Fins mostly hyaline with irregularly set black spots on rays, but dorsal and caudal fins rays partly dusty grey or black. In life: ventral half of body silvery, while dorsal half greenishyellow. Black speckles overlaid on head and body. Fins hyaline with black spots on rays of dorsal and caudal fins.

Distribution and habitat: Tariqilabeo iranicus sp. nov. is currently known from the Gabrik, Jagin and Nikshahr River drainages in the Makran basin, Iran ( Fig. 8 View FIGURE 8 ). There is no previous record of this species from the Jagin and Gabrik Rivers ( Jouladeh-Roudbar et al. 2020; Çiçek et al. 2024; Fricke et al. 2024; Sayyadzadeh & Esmaeili 2024). The type locality was below a dam, and the flow may have been completely blocked by this dam in dry seasons. The population was found on a small stretch of the Jagin River. At the type locality, the river was shallow, about 20 m wide, with a substrate consisting of coarse gravel, small boulders, and precast concrete, with moderate flow and semi-transparent water. At the sampling site of the Gabrik River, the river was about 10–20 m wide, with a substrate consisting of coarse gravel and small boulders, with low flow and muddy water due to rainfall. Drought, unmanaged water use, habitat fragmentation, and pollution are the main threats to this fish. Its biology is unknown.

Etymology. The species is named for Iran, from where it is described, and assumed endemic to.

English name. Iran Latia

Comparative Remarks

For a long time, there have been several taxonomic issues regarding the status of genera included in the cyprinid tribe Labeonini (e.g., Akrokolioplax , Gonorhynchus , Crossocheilus ) ( Zhang & Kottelat 2006; Yang & Mayden 2010; Yang et al. 2012; Kottelat 2016; Ciccotto & Page 2016, 2017). This tribe, widely distributed in the freshwaters of tropical Africa and Asia, is adapted to fast-flowing streams and rivers and displays exclusive morphological modifications associated with their lips and other structures around the mouth, which have long been used as diagnostic characters ( Ciccotto & Page 2016).

Based on morphological characters (see Zhang & Kottelat 2006; Sayyadzadeh et al. 2015; Ciccotto & Page 2016) and genetic analyses using nuclear and/or mitochondrial genes) (e.g., Yang et al. 2012; Sayyadzadeh et al. 2015) including the present study, we consider the following taxa as valid species: T. adiscus , T. diplochilus , T. bicornis , T. burmanicus , T. latius , T. macmahoni , T. periyarensis , T. wattanah , and T. iranicus sp. nov. Nevertheless, Kottelat (2016) conservatively retained Akrokolioplax and rejected the inclusion of A. bicornis in the genus Tariqilabeo because of i) the limited number of taxa used in the phylogenetic analysis of Yang et al. (2012), ii) the unresolved issues with the identity of T. burmanicus , iii) additional species having rostral flaps apparently homologous with those of Akrokolioplax , and iv) the changes in the reconstructed molecular phylogenetic trees when more species or genes are included in the analysis ( Kottelat 2016).

However, Ciccotto & Page (2017) rejected Kottelat’s (2016) criticism and, based on Yang et al. (2012), and the morphological diagnoses of the species of Gonorhynchus (now Tariqilabeo ) provided by Ciccotto & Page (2016), considered T. bicornis a valid name and Akrokolioplax as a junior synonym of Tariqilabeo . Another taxonomic issue is the recognition of T. latius and T. diplochilus . Due to the morphological similarity of these two putative species, Ciccotto & Page (2016) suggested that populations distinguished as T. latius and T. diplochilus may represent a single species displaying clinal morphological variation across a vast geographic distribution range. Presently, as access to samples across the distribution range of T. latius in South Asia including Ganges, Brahmaputra, and Meghna Rivers ( Nepal, Bhutan, India and Bangladesh), and T. diplochilus from Indus, Sistan and Helmand Rivers ( Afghanistan, Pakistan, and India), is difficult, we rely on the molecular data and observed morphological differences by Yang et al. (2012), Sayyadzadeh et al. (2015), and Ciccotto & Page (2016). Based on these studies, we consider them as two distinct species, pending the availability of further information. Despite the wide geographic distribution range of T. diplochilus in south and West Asia, from India to Iran (Indus, Sistan, and Helmand Rivers), which may promote divergence via allopatric speciation, all populations are considered as a single species. As suggested by Ciccotto & Page (2016), the collection of samples from throughout the distribution range of T. diplochilus is required to obtain additional morphological characters and molecular data (multiple nuclear and mitochondrial genes) to check for population-level differences, or whether they are indeed two distinct species.

Another nominal taxon from Asia is Crossochilus latius punjabensis which was originally described by Mukerji (1934:53, fig. 7) from Katas Nallah, Salt Range and Khewra Gorge in Punjab, at an elevation of about 2000 feet. When describing this lndus basin form as a distinct subspecies, Mukerji provided the following distinctive characters to differentiate it from the typical Crossocheilus (now Tariqilabeo ) latius , described from the Tista River (Brahmaputra basin): i.e., deeper body (body depth greater than dorsal-fin height vs. body depth lesser than dorsal-fin height), smaller eye (eye diameter 4.2 to 4.7 times in head length vs. 3.6 to 3.7).

Bănărescu (1986) regarded the nominal typical form, Crossocheilus latius , as a subspecies ( C. latius latius ) and classified Mukerji’s C. latius punjabensis as a junior synonym of C. latius diplocheilus . The primary differences between these two subspecies are the number of lateral-line scales (36–38, rarely 35 or 39 in the former vs. 39–41, rarely 38 in the latter) and circumpeduncular scale rows (18–20 in the former vs. 16 in the latter). Bănărescu (1986) pointed out that the differences given by Mukerji (1934) are valid, except the body depth, which shows the same values in both subspecies. However, the least body depth as percentage of standard length (% SL) is higher, and the ventral-anal distance as percentage of standard length (% SL) is lower in the Indus basin subspecies. Bianco & Bănărescu (1982), and Talwar & Jhingran (1991) considered C. latius punjabensis as junior synonym of Crossocheilus latius , while Kullander et al. (1999) regarded it as a junior synonym of Crossocheilus diplochilus . Currently, it is treated as a synonym of Tariqilabeo diplochilus ( Jouladeh-Roudbar et al. 2020; Çiçek et al. 2024).