Cabdio occidentalis, Jouladeh-Roudbar & Vatandoust & Ghanavi & Freyhof, 2023

Jouladeh-Roudbar, Arash, Vatandoust, Saber, Ghanavi, Hamid Reza & Freyhof, Jörg, 2023, Cabdio occidentalis, a new species from Lake Mashkid basin and the Makran region (Teleostei: Danionidae), Zootaxa 5360 (3), pp. 437-447 : 441-444

Cabdio occidentalis , new species

( Figs. 3–5 )

Holotype. BIAUBM 2-H, 1, 77 mm SL; Iran: Sistan and Baluchestan prov. : Sarbaz at Pirdan ( Fig. 6 ), 26.52831 61.20721.

Paratypes. AJRPC 11 , 1 , 71 mm SL ; FSJF 4120 , 1 , 65 mm SL; data same as holotype .— AJRPC 12 , 1 , 69 mm SL ; FSJF 4121 , 1 , 65 mm SL; BIAUBM 2-P, 63–68 mm SL; MNCN-ICTIO 296.955–296.957, 2, 55 – 72 mm SL; Sistan and Baluchestan province: Mashkid at Govarnagan , 27.17064 62.26233 . MZLU L020 /000008-10, 3, 46– 46 mm SL; same data as holotype .

Material used in molecular genetic analysis. FSJF-DNA 3177 , FSJF-DNA 3183 , FSJF-DNA 3184 , Sistan and Baluchestan prov. : Sarbaz south of Sarbaz, 26.62286 61.25977. (GenBank Accession Numbers: OR294232- OR294234) .

Additional distribution records. 25.6570 61.0500, 26.4735 59.9940, 27.1011 61.8527 (AJR personal observation).

Diagnosis. Cabdio occidentalis is distinguished from all other species of Cabdio by lacking a keel on abdomen (vs. median scales on abdomen behind pelvic-fin base forming a keel, in all other species). It further differs from C. crassus in having 38–42 lateral-line scales (vs. 45–51), 8½–9½ branched anal-fin rays (vs. 11½–12½), and 9–11 branched pectoral-fin rays (vs. 12–14). The new species is further distinguished from C. jaya in having 38–42 lateral-line scales (vs. 52–60), and 8½–9½ branched anal-fin rays (vs. 7½). Cabdio occidentalis is distinguished from C. ukhrulensis in having 38–42 total lateral-line scales (vs 35–37), 9–11 branched pectoral-fin rays (vs 12–13), and 19–23 predorsal scales (vs. 14–16). It is distinguished from C. morar in having 19–23 predorsal scales (vs. 17–18), 7½ scale rows between dorsal-fin origin and lateral-line scales (vs 5½), and 9–11 branched pectoral-fin rays (vs 13–14).

Description. See Table 2 for morphometric data and Figure 2 for general appearance. Body elongate, laterally compressed, body deepest at short distance in front of dorsal-fin origin. Dorsal profile rising from tip of snout to dorsal-fin origin, then gradually sloping towards caudal peduncle. Ventral profile convex up to caudal peduncle; dorsal and ventral profile of caudal peduncle slightly concave. Mouth small, subterminal. Lower jaw straight, with slightly keratinized cutting edge. Dorsal fin origin in front of, or slightly behind pelvic-fin origin. Pelvic axillary scales elongate. Absence of barbel and keel on abdomen. Anus close to anal-fin origin. Head compressed along entire length, its depth greater than its width. Dorsal fin with 2 (9) unbranched and 7½ (6) or 8½ (3) branched rays. Pectoral fin with 1 unbranched and 9 (1), 10 (4) or 11 (4) branched rays. Pelvic fin with 1 unbranched and 7 (9) branched rays. Anal fin with 3 unbranched and 8½ (2) or 9½ (7) branched rays. Caudal fin forked, with 17 (9) branched rays, its lobes about equal length. Lateral line complete, with 40 (1), 41 (4), 43 (3) or 44 (1) scales; 7 (9) scales between lateral line and dorsal-fin origin, and 3 (9) scales between lateral line and anal-fin origin. Circumpeduncular scales 16 (7) or 17 (2), predorsal scales 19 (2), 20 (2), 21 (3), 22 (1) or 23 (1).

Coloration. In life, back light-brown to silvery-brown. Many melanophores on back and upper flank. Flank silvery, often with a yellowish hue, abdomen slightly paler than flank. Fins, especially caudal fin, orange-yellow, hyaline in most individuals. Melanophores on fin membranes in some individuals. In preserved, back yellowish brown. Melanophores on the back and upper flank not distinctive. Flank and abdomen cream to yellow. Fins mostly hyaline.

Distribution. Cabdio occidentalis is known from the Sarbaz, Bahoo Kalat, and Tang-e Sarheh rivers of the Makran region and the Mashkid River, a tributary of the endorheic Lake Mashkid. Both, Makran and Lake Mashkid basin are transboundary areas, and it is expected that C. occidentalis also occurs in the Pakistani part of the Makran region and Lake Mashkid basin. In Pakistani Baluchistan, Mirza (1972) reported Cabdio from several places west of the Indus, as Babar Kach (Nari drainage, Sibi District), Mashkai (Hingol drainage, Kalat District), Panjur (Rakhshan drainage), Turbat (Kech drainage) (both in Makran District) and Zugmayer (1913) reported it from Las Bela, an area just west of the Indus delta.

Etymology. The new species is named “occidentalis ”, Latin for “westerly”, referring to the western-most species of the genus. An adjective.

Figures

FIGURE 2. Phylogenetic reconstruction of the relationships of different Cabdio species based on the Maximum likelihood and Bayesian analysis of the mitochondrial DNA barcode region. Numbers near nodes are UFBoot/SH-aLRT/Posterior Probability values. The tree is drawn to scale with branch lengths depicting number of substitutions per site. The list of sequences is presented in Table 1.

FIGURE 3. Cabdio occidentalis, paratype, AJRPC 12, 69 mm SL; Iran, Mashkid River.

FIGURE 4. Cabdio occidentalis, paratype, FSJF 4120, 65 mm SL; Iran: Mashkid River.

FIGURE 5. Cabdio occidentalis, from top: BIAUBM 2-H, holotype, 77 mm SL; AJRPC 11, 71 mm SL; FSJF 4120, 65 mm SL, Iran: Sarbaz River.

FIGURE 6. Mouth shape of Cabdio occidentalis, left: FSJF 4120, right: FSJF 4121.