Threatened Fishes of the World: Aphanius Isfahanensis Hrbek, Keivany & Coad, 2006 (Cyprinodontidae)
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AQUA19(2):AQUA 02/05/13 09:50 Pagina 67 aqua, International Journal of Ichthyology Threatened fishes of the world: Aphanius isfahanensis Hrbek, Keivany & Coad, 2006 (Cyprinodontidae) Yazdan Keivany Department of Natural Resources (Fisheries Division), Isfahan University of Technology, Isfahan, Iran, 84156; Tel: (311) 391-3572 – Fax: (311) 391-2840. E-mail: [email protected] Received: 12 February 2013 – Accepted: 26 March 2013 Abstract Sommario The systematics, morphology, ecology and biology of an La sistematica, la morfologia, l'ecologia e la biologia del Isfahan endemic toothcarp, Aphanius isfahanensis Hrbek, nono Aphanius isfahanensis Hrbek, Keivany e Coad, 2006 Keivany & Coad, 2006 (Cyprinodontidae) are summa- (Cyprinodontidae), endemico dell'Esfahan, sono riassunte. rized. This fish is not listed in IUCN’s Red Data Book, Questo pesce non è elencato nel Libro Rosso dell'IUCN, but it should be due to criteria such as restricted distribu- ma dovrebbe esserlo a causa di criteri quali la distribuzione tion, destruction of spawning grounds, dam construction, limitata, la distruzione delle zone di riproduzione, la co- and environmental pollution. This vulnerable species has struzione di dighe e l'inquinamento ambientale. Questa considerable ecological importance, but there are little specie vulnerabile ha una notevole importanza ecologica, data on its biology. The limited data on its distribution, ma ci sono pochi dati sulla sua biologia. Quelli disponibili ecology, reproduction and threats are summarized and sulla sua distribuzione, l'ecologia, la riproduzione e le mi- discussed. nacce sono riassunte e discusse. Zusammenfassung INTRODUCTION Zu dem in Isfahan, Iran, endemischen Zahnkärpfling The species of the pupfish genus Aphanius Nardo, Apha nius isfahanensis Hrbek, Keivany & Coad, 2006 (Cy pri - 1827 (Cyprinodontiformes) are widely distributed nodontidae) werden Systematik, Morphologie, Ökologie along the late period Tethys Sea coastlines (Smith und Biologie zusammengefasst. Die Fischart wird in der Roten Liste gefährdeter Arten der IUCN nicht aufgeführt, et al., 1995). The distribution includes coastal sie sollte aber hinzugefügt werden, wenn man die einge - areas of the Mediterranean region to Red Sea and schränkte Verbreitung, die Zerstörung der Laichgründe, den the Persian Gulf. Inland distribution is restricted negativen Einfluss von Dammbauten und die Umweltver- primarily to the Mediterranean and the Near East schmutzung zum Maßstab nimmt. Die anfällige Art ist von orogenic belt, including Iran (Hrbek et al. 2002). erheblicher ökologischer Bedeutung, doch gibt es nur spär- Distribution, taxonomy and biology of Aphanius liche Daten über ihre Biologie. Die wenigen vorhandenen in Iran have been subject of several works (Coad, Daten zu Verbreitung, Ökologie, Fortpflanzung und Gefähr - 1996, 2000; Keivany and Soofiani 2004; Esmaeili dung werden zusammengefasst und diskutiert. et al. 2006; 2007; 2009; 2012; Bibak et al. 2012; Résumé Golmoradizadeh et al. 2012). However, only basic La systématique, la morphologie, l’écologie et la biologie data on A. isfahanensis Hrbek, Keivany & Coad, d’un Cyprinodontidé endémique d’Isfahan, Aphanius isfaha- 2006, exist (Hrbek et al. 2006, Esmaeili et al. 2008; nensis Hrbek, Keivany & Coad, 2006 (Cyprinodontidae) Torabian et al. 2010; Alavi-Yeganeh et al. 2011). sont résumées. Ce poisson ne figure pas dans le livre des Distribution: This species is restricted to Zayan- listes rouges de l’IUCN, ce qui pourrait être dû à des critères dehrud River in Isfahan Basin, central Iran. So far, comme la distribution réduite, la destruction de zones de it is known only from three localities, the type reproduction, la construction de barrages et la pollution locality, Varzaneh Bridge, Zarrinshahr and environnementale. Cette espèce vulnérable a une importan - ce écologique considérable, mais il y a peu d’informations Gavkhoni Wetland (Hrbek et al. 2006, Torabian et sur sa biologie. Les quelques données sur sa distribution, son al. 2010) (Fig. 1). éco logie, sa reproduction et ses menaces sont résumées et Identification: Aphanius isfahanensis is distin- discutées. guished at genetic level from all other species of 67 aqua vol. 19 no. 2 - 26 April 2013 AQUA19(2):AQUA 02/05/13 09:50 Pagina 68 Threatened fishes of the world: Aphanius isfahanensis Hrbek, Keivany & Coad, 2006 (Cyprinodontidae) Aphanius with 82 molecular apomorphies, 19 Habitat and ecology: The type locality is near transversion, 2 transver-sions/transitions and 61 the town of Varzaneh on the lower reaches of the transitions, which show fixed character states dif- Zayandehrud River, about 30 km up river from the ferences to homologous characters analyzed in terminal swamp, the Gavkhuni Wetland. Water other species from Iran (Hrbek et al. 2006). temperature was 27°C, pH 6.7, brackish (EC 10.9 Males of A. isfahanensis (Figs 2a, 3) can be distin- mS), dissolved solids 5450 ppm, dissolved oxygen guished from those of all other Iranian species by 12.3 mg/L. Current was slow and there was no having a distinct black edge on the dorsal, anal and cover from riparian vegetation. This fish is now pelvic fins. The dorsal fin is covered with a high found in a park pool in Esfahan City (Fig. 5). density of black blotches. Females of A. isfahanen- The typical habitat consists of slow-running sis (Fig 2b) can be distinguished from females of A. waters with rich aquatic vegetation, where the sophiae and A. vladykovi by having flank-bars rather fishes exhibit cryptic behavior, remaining among than spots. It can also be distinguished from A. per- aquatic vegetation during most of the day and sicus by less well-defined bars terminating at a mid- being rarely seen in the open areas. In most areas, flank stripe and a relatively light grey stripe at the this species occurs in sympatry with the introduced caudal fin base rather than a black spot or blotch. Gambusia holbrooki Girard, 1859. It feeds mainly Aphanius isfahanensis can be distinguished unam- on aquatic insect larvae and associated algae. Max- biguously only from A. vladykovi by a lower lateral imum age is less than 3 years and maximum line scale count (Hrbek et al. 2006). recorded total length is 45 mm. Counts of male flank bars are significantly fewer Spawning occurs mainly in April to July. The than in A. sophiae. The bars are broad with inter- development of larvae and juveniles is known from spaces about equal or slightly narrower. The bars both field observations and breeding in aquaria. extend from behind the head to the tail. Anterior Larvae hatch at about 7 mm total length and bars fade on the belly, whereas, posteriorly on the exhibit the general morphological characteristics of caudal peduncle, they encircle the body. The eye is the genus. Adult morphology is acquired at about bounded ventrally and postero-ventrally by a thin 15 mm total length. Maturity attained at about 30 line of black pigment. The anal fin has a broad, mm total length (Keivany et al. 2013). The blackish margin with the rest of the fin light absolute fecundity ranges between 120-390 eggs cream-colored. The caudal fin rays and membranes with a diameter of up to 1.5 mm. The sex ratio is are sparsely pigmented and the whole margin may 0.8F:1M (Torabian et al. 2010). be blackish, but in most fish pigment is restricted Threats: The type locality, near the end of the to the upper and lower margins. Zayandehrud River in Varzaneh, and the Gavkhoni Wetland are experiencing drought for much of the year, especially in recent years, and Zarrinshahr local- ity, is subject to pollution. Most of the creeks which were the major habitat of this species have been totally destroyed or turned into concrete canals. a b Fig. 1. Distribution map of Aphanius isfahanensis in Fig. 2. Photos of Aphanius isfahanensis dead specimens. Zayandehrud River. a) a male; b) a female. Photo by Y. Keivany. aqua vol. 19 no. 2 - 26 April 2013 68 AQUA19(2):AQUA 02/05/13 09:50 Pagina 69 Yazdan Keivany Fig. 3. Photo of a male Aphanius isfahanensis in an aquarium. Photo by H. Bleher. BRIEF DISCUSSION tionary force in this group of fishes. However, sex- The geological history of Iran has been shaped by ually selected color patterns are often convergent geological events associated with the closing of the among species of Aphanius. Tethys Sea. Sampling and analysis of central popu- Unfortunately, the published data on different lations of Aphanius revealed at least nine deeply aspects of A. isfahanensis is limited. Therefore, divergent species (Hrbek et al. 2002; Hrbek et al. effort on the part of scientists and governments 2006; Teimori et al. 2011; 2012). All lineages should be made in understanding the biology, ecol- investigated are allopatrically distributed in sepa- ogy and behavior of this vulnerable species. One rate hydrological basins. key objective in working with endangered species is A noticeable feature of the ichthyofauna of the to increase the number of individuals of the species Near East is the relative high degree of conser- concerned by artificially/controlled reproduction vatism of external morphology in spite of substan- in captivity. Unfortunately, there is no policy for tial genetic divergence. In analysis of the Iranian preserving this species in Zayandehrud River. members of the eastern clade of Aphanius (Hrbek I recommend the protection of these three locali- & Meyer 2003) there are no fixed external mor- ties and preservation of habitats of the species, phological characters that would distinguish A. especially in Zarrinshahr area. These areas may be isfahanensis from its closest relatives. Aphanius isfa- threatened by projected plans for the alignment hanensis can be distinguished by non-overlapping and diversion of Zayandehrud River, which is the lateral line scale number only from A. vladykovi. major source of water for the channels and wells of Species of Aphanius also often differ in male color the area. I also recommend the introduction of the pattern since sexual selection is the major evolu- species to suitable nearby water bodies and educa- tion of local communities.