Iranocichla persa, Esmaeili, Hamid Reza, Sayyadzadeh, Golnaz & Seehausen, Ole, 2016

Esmaeili, Hamid Reza, Sayyadzadeh, Golnaz & Seehausen, Ole, 2016, Iranocichlapersa, a new cichlid species from southern Iran (Teleostei, Cichlidae), ZooKeys 636, pp. 141-161 : 143-153

Iranocichla persa sp. n. Figs 3, 4, 5

Holotype.

ZM-CBSU IP66, 89 mm SL; Iran: Hormuzgan prov.: Shur River approx. 30 km east of Bandar Abbas, 27°17'40.10"N 56°29'15.68"E; H. R. Esmaeili, M. Masoudi, H. Mehraban, A. Gholamifard & N. Shabani, 12 March 2013.

Paratypes.

All from Iran: Hormuzgan prov.: ZM-CBSU IP64, 2, 65-87 mm SL, same data as holotype. ZM-CBSU IP67-ZM-CBSU K1120, 20, 65-86 mm SL; Khorgo (Khorgu) hot spring approx. 50 km north east of Bandar Abbas, 27°31'21.3"N 56°28'12.7"E; H. R. Esmaeili, M. Masoudi, H. Mehraban, A. Gholamifard & N. Shabani, 12 March 2013. - ZM-CBSU IP59, 5, 74-88 mm SL; Rudan river at Ziarat Ali village, approx. 30 km north of Rudan, 27°45'44.42"N 57°14'34.33"E; H. R. Esmaeili, M. Masoudi, H. Mehraban, A. Gholamifard & Shabani, 11 March 2013. -ZM-CBSU IP141, 5, 82-102 mm SL; Rudan river at Ziarat Ali village, approx. 30 km north of Rudan, 27°45'44.42"N 57°14'34.33"E; M. Masoudi & H. Mehraban, 9 April 2014. -FSJF 3468, 63-81 mm SL; Khorgo Hot spring approx. 50 km north east of Bandar Abbas, 27°31'21.3"N 56°28'12.7"E; H. R. Esmaeili, M. Masoudi, H. Mehraban, A. Gholamifard & N. Shabani, 12 March 2013.

Materials used for molecular analysis.

All from Iran: Hormuzgan prov.: ZM-CBSU M919, M920, M940, M941; Khorgo hot spring, 27°31'21.3"N 56°28'12.7"E (GenBank accession numbers: KY034435, KY034436, KY034437, KY034438). - ZM-CBSU M1120, M1121, ZM-CBSU-IH59, ZM-CBSU-IH60, ZM-CBSU-IH61; Rudan River at Ziarat Ali village, 27°45'44.42"N 57°14'34.33"E (GenBank accession numbers: KY034442, KY034443, KY034439, KY034440, KY034441). -ZM-CBSU-IH64, ZM-CBSU-IH65; Shur River, 27°17'40.10"N 56°29'15.68"E (GenBank accession numbers: KY034444, KY034445).

Diagnosis.

Iranocichla persa is distinguished from Iranocichla hormuzensis by its nuptial coloration in males. In Iranocichla persa , the lower part of the head and breast are orange (vs. black), the background colour of the flank is grey with an orange hue (vs. black), each scale is furnished with an iridescent patch and these patches take up more space (vs. less) than the space between them, a poorly developed or invisible (vs. distinctive) " Tilapia -mark" in the dorsal fin, and very clear white spots making almost wavy bars or stripes on the caudal fin (vs. without or with very few white spots). Both species are also distinguished by multiple fixed molecular characters in mitochondrial ND2, D-loop (see Schwarzer et al. 2016).

Description.

See Figure 3-5 for general appearance. Morphometric data are provided in Table 1. A small species with greatest body depth at approximately fifth dorsal-fin spine. Dorsal body profile convex from anterior part of dorsal fin to caudal peduncle. Ventral body profile straight or slightly convex between pelvic and anal fins. Dorsal head profile straight, slightly concave between nostrils and interorbital space. Head and eyes large. Mouth terminal, tip of upper and lower jaws at same vertical line (isognathous). Upper lip noticeably thickened, buccal region enlarged ventrally, oral teeth uniform in size and not enlarged medially.

Dorsal-fin base long, its origin at a vertical of pectoral-fin base, base of last dorsal-fin ray at vertical of posterior part of anal-fin base. Posterior dorsal-fin tip reaching to a point slightly in front of caudal-fin origin when folded back. Dorsal fin with 14-17 spines and 9½-10½ branched rays. Anal fin with 3 spines and 6½-8½ branched rays. Pelvic fin with 1 spine and 5 branched rays, not reaching to anus. Pectoral fin long with 11-12 branched rays, third branched ray being longest, reaching to vertical of 9th-11th dorsal-fin spine. Caudal fin truncate or slightly emarginated with 8+8 or 9+8 branched rays. Upper lateral line with 17-24 pored scales, starting from posterior tip of operculum to a vertical of 3rd-4th branched dorsal-fin ray. Lower lateral line with 9-13 pored scales, reaching from a vertical of 3rd-4th branched dorsal fin rays to caudal-fin base. Scales cycloid or having very small ctenius-like structure, regularly arranged on flanks except that in a few larger individuals (≥85 mm SL; 3 out of 9 specimens), where scale rows are interspaced by irregularly set smaller scales, particularly on the upper flank. Head without scales in some individuals, dorsal and anal fin bases without scales, no scale between the pectoral and pelvic fin bases and none on the belly and isthmus anterior to the pelvic fin. Upper margin of operculum without scales or with 1-2 large scales next to each other and subopercular bone without scales or with one scale at middle. Cheek without scales or with 1-3 rows of 1-7 almost non-imbricate scales. 11-12 rows of small scales on caudal-fin base, extending distally along more than half of the fin ray length in some individuals and extending distally along equal or less than half in some others.

Teeth in oral jaws regularly or irregularly arranged, 3-4 rows in both jaws (of the four examined, two individuals with 3 rows in upper and 4 in lower jaw). Number of rows decreases laterally to one row at rictus. Teeth in outer row widely spaced, spaces often nearly as wide as the crown, mostly bicuspid, major cusp with a protracted flank, but a few teeth tricuspid. Teeth in inner row tricuspid, central cusp largest (see Figs 6-8).

Sexual dimorphism.

Nuptial males with an orange breast and lower part of head and few roundish white spots on cheek and operculum. Females have a longer head on average (33-38% SL vs. 34-37% SL), a wider interorbital distance (26-39% HL vs. 27-33% HL) and shorter pelvic fin (16-20% SL vs. 17-23% SL) as compared to males.

Colouration.

In life. Background colour silvery grey or yellowish, a dark grey narrow saddle between eyes and a dark grey band at nape between uppermost parts of operculum. A dark grey, faint mid-lateral stripe between posterior eye margin and caudal-fin base and a second, often indistinct, dorso-lateral stripe between nape and " Tilapia mark". Dorso-lateral stripe often dissociated into a marbled pattern. Mid-lateral stripe often dissociated into a series of vertically elongated large blotches at intersection with vertical bars. Body with 6-11 (mode 8) faint, wide, vertical bars, first bar at level of third dorsal-fin spine, last bar on posterior-most caudal peduncle. Bars most prominent above midlateral line, faded below. Bars almost or fully absent in nuptial males. Dorsal fin hyaline or grey with black " Tilapia mark" on posterior part of dorsal fin (absent in nuptial males). Caudal, anal, pelvic and pectoral fins grey or hyaline. Caudal fin with a series of 5-6 narrow vertical bars in some males, uniformly grey in other males and in all females.

Nuptial males with a prominent orange hue on flank. " Tilapia mark" absent. Lower head to upper eye margin orange, in some individuals with very small dark brown spots. Roundish white iridescent spots on cheek and operculum, Breast pale or orange. Breast and belly with very small dark brown spots in some individuals. Forehead and nape black in some individuals. Lips black at outer margin and orange at inner margin. Body except breast and nape with a prominent iridescent spot or small blotch on each scale. White blotches narrow, comma shaped, vertically elongated, most prominent on or restricted to posterior scale margins on upper flank above a horizontal line between pectoral-fin origin and posterior anal-fin base or a bit above that line. Below that line, iridescent spots and blotches on posterior scale margin roundish or ovoid, often irregularly shaped. On caudal peduncle and body behind a vertical line between last dorsal-fin spine and anal-fin origin, white spots narrow, restricted to posterior scale margin or along complete free scale margin, forming a reticulate pattern on caudal peduncle. Some individuals with irregularly x-shaped white blotches on anterior flank, roundish or ovoid on belly and comma-shaped, short vermiculate or roundish on dorsal and posterior flank. Dorsal fin with orange margin in most nuptial males, black in others. Dorsal fin rays hyaline, grey or black. Spines, membranes with white roundish or vertically elongated blotches, some fused to forward slanted narrow bars. Caudal fin grey or black with very clear white spots making almost wavy bars or stripes on the caudal fin. Anal fin grey with black distal anterior edge, with a few white, roundish, elongate or comma shaped blotches, most prominent on proximal and posterior parts of anal fin, absent on distal and anterior parts. Pelvic fin grey, light blue or black with few or no white spots or blotches. Pectoral fin hyaline or with black rays.

Distribution.

Iranocichla persa is known from the Shur (Fig. 9), Hasanlangi and Minab River drainages flowing to the Persian Gulf at the Strait of Hormuz (Fig. 1).

Etymology.

The species is named for Persia, the ancient name of Iran.

Remarks on populations from the Kol River drainage.

The Kol River drainage is situated geographically between the Mehran River drainage, inhabited by Iranocichla hormuzensis , and the Shur River drainage, inhabited by Iranocichla persa (Fig. 1). The Kol popula tions (Figs 4, 10) show some morphological characters resembling Iranocichla hormuzensis and others resembling Iranocichla persa . Nuptial males from the Kol River drainage resemble Iranocichla hormuzensis in having a black breast and lower part of the head (vs. orange in Iranocichla persa ). On the other hand, nuptial males from the Kol River drainage resemble Iranocichla persa in having only a much faded " Tilapia -mark" in the dorsal fin or none at all (vs. bold in Iranocichla hormuzensis ) (see Figs 3, 4, 10, 11), and in having very clear white spots making almost wavy bars or stripes on the caudal fin (vs. without or with very few white spots in Iranocichla hormuzensis ) (Figs 4, 11). There is one exception, these are fishes from the Faryab hot spring, which is a quite isolated small spring situated in the upper most reaches of the Kol River drainage (Fig. 1). In the Faryab hot spring, males resemble the nuptial coloration of those from Mehran River, albeit being nearly black with iridescent blue spots on caudal and dorsal fin being connected to stripes. However, our two males in breeding dress from this hot spring were smaller than those sampled from any of our other sites and larger male individuals from Faryab are needed to rule out an ontoge netic effect on the presence of " Tilapia -mark". The nuptial males from the Shur and Minab River drainages have an orange edge to the dorsal fin. Nearly no differences in individual morphometric and meristic characters were found between the populations from the Kol and those from the Shur and Minab River drainages (Tables 1-3). The Kol populations resemble the latter and differ from Iranocichla hormuzensis in having a slightly more decurved dorsal head profile and a less pointed snout (Fig. 4).

From a genetic point of view, according to Schwarzer et al. (2016), who used ND2 and D-loop sequences, the western Kol River populations combined (Kol, Gode-Gaz, Faryab, Tange-Dalan) but also Gode-Gaz and Faryab each on its own, were genetically more diverse than Iranocichla populations of other drainages, having 15 different haplotypes, none of which was shared with any other drainage system and making two clades separated by a minimum of 4 mutations. All of them belonged to clade B of Schwarzer et al., but while one of the clades was unique to the Kol drainage populations, sharing a relatively recent common ancestral haplotype with the Iranocichla persa haplotype clade, the other Kol river clade was shared with Iranocichla persa , albeit with many distinct haplotypes. Based on these results, Schwarzer et al. (2016) concluded that the nearly complete lack of haplotype sharing between the rivers, combined with distinct differences in male nuptial coloration, suggests the existence of two younger allopatric species within Clade B (Kol, Shur and Minab River systems): a red headed species in Shur, Hasanlangi and Minab (described as Iranocichla persa here) and a dark black one in the Kol river. The divergence of these forms is more recent and the western Kol populations appear to be para- or polyphyletic assemblages in their mitochondrial genes, possibly suggesting an old stable population or a case of more recent secondary contact and admixture with gene flow from the Shur River into the Kol River. The eastern arm of the Kol river harbours only one of the two haplotype clades, but Schwarzer et al. (2016) had limited sampling from that river arm. Note that the persistence of two divergent haplotype clades only in the western arm of the Kol River does not seem to be associated with any obvious phenotypic polymorphism within these sites, hence we do not see evidence for more than one species in any one river.