In recent years, policy-makers have sought the development of appropriate tools to prevent and manage introductions of invasive species. However, these tools are not well suited for introductions of non-target species that are unknowingly released alongside intentionally-introduced species. The most compelling example of such invasion is arguably the topmouth gudgeon Pseudorasbora parva, a small cyprinid species originating from East Asia. A combination of sociological, economical and biological factors has fuelled their rapid invasion since the 1960s; 32 countries (from Central Asia to North Africa) have been invaded in less than 50 years. Based on a combination of monitoring surveys (2535 populations sampled) and literature reviews, this paper aims to quantify and characterise important invasion parameters, such as pathways of introduction, time between introduction and detection, lag phase and plasticity of life history traits. Every decade, five new countries have reported

Aphanius Nardo, 1827 (Actinopterygii, Cyprinodontidae) is a widely distributed genus in the Mediterranean and Persian Gulf area and includes several endangered species. The otolith morphology in Aphanius is known to represent a valuable tool for the taxonomy, and is also indicative for the genetic diversity of a particular population. The present study focuses on the otoliths of the endangered A. ginaonis (Holly, 1929), which is endemic to the Geno hot spring in southern Iran. The taxonomic status of A. ginaonis has repeatedly been questioned, and some scholars have argued that it merely represents a morphological variation of the widespread A. dispar. We present a comparison of the otolith morphology of A. ginaonis (52 specimens) with that of A. dispar (Rüppell, 1828) from the Mehran River Basin (southern Iran) (17 specimens) and an A. dispar population from the Persian Gulf coast of the United Arab Emirates (32 specimens). Our data obtained from SEM pictures, otolith morphometry and statistical analyses suggest that A. ginaonis represents a valid species. In A. ginaonis individuals with a standard length exceeding 23 mm, the otolith variables lengthheight and rostrum length represent useful complementary diagnostic characters discriminating this species from other Aphanius species. Besides ontogenetic variation, we found extremely high otolith form variability in A. ginaonis, including some otoliths with a morphology distinctly deviating from the basic morphology type. We hypothesize that these variations may be a result of the artificial introduction of A. dispar into the Geno hot spring during the last years and subsequent hybridisation.

The Arabian cyprinodontid Aphanius dispar (Ru¨ppell, 1829) is known to show considerable morphological variation. It has remained unknown, however, whether this variation is a result of environmental differences or allopatric divergence owing to geographical isolation. In this study, 11 populations of A. dispar from three geographically separated basins were analysed, that is, the Makran Basin (I, one river system), the Hormuzgan Basin (II, five rivers and three hot springs) and the Helleh Basin (III, two hot springs) in southern Iran. Statistical analyses do not indicate significant differences between the fishes from river and hot spring habitats (T-test, p < 0.05), which is also supported by the Canonical Discriminant Analysis (CDA). Nevertheless, morphometric and meristic characters of the fishes, as well as otolith morphology and morphometry, demonstrate that six phenotypic characters discriminate the A. dispar populations of the three basins, that is, (1) predorsal distance (Prdd.SL), (2) head length (HL.SL), (3) pelvic fin length (Lplf.SL), (4) number of pelvic fin rays, as well as relative length of both the (5) medial part and (6) rostrum of the otolith. In addition, these characters display a consistent pattern of variation, thus providing support for the assumption that the phenotypically different A. dispar populations are a result of geographical isolation and not related to environmental differences. It is likely that the geological history of the drainage systems caused isolation event(s) that may date back to the Pleistocene (1.8 million years before present). The high phenotypic differences might suggest that the A. dispar populations from the three studied basins represent separate subspecies or even species.

A new species of tooth-carp, Aphanius arakensis sp. n., is described from the Namak Lake basin in Iran. The new species is distinguished by the congeners distributed in Iran by the following combination of characters: 10–12 anal fin rays, 28–32 lateral line scales, 10–13 caudal peduncle scales, 8–10 gill rakers, 12–19, commonly 15–16, clearly defined flank bars in males, a more prominent pigmentation along the flank added by relatively big blotches in the middle and posterior flank segments in females, a short but high antirostrum of the otolith that has a wide excisura, and a ventral rim with some small, drop-like processes, and 19 molecular apomorphies (17 transitions, two transversions) in the cytochrome b gene. It was suggested based on the phylogenetic analysis that the new species is sister to Aphanius sophiae from the Kor River and that Aphanius farsicus from the Maharlu Lake basin is sister to Aphanius arakensis plus Aphanius sophiae. A noticeable feature of the Aphanius diversity in Iran is the conservatism of the external morphology as well as morphometric and meristic characters, while distinctive differences are present in genetic characters, otolith morphology, and male color pattern. Transformation of the latter was probably driven by sexual selection.

No abstract

A substantial number of species within the tooth-carp Aphanius Nardo, 1827 (Cyprinodontidae, Teleostei) has been re-corded from the endorheic drainage systems of Iran, and several isolated populations in these systems may deserve species status. Descriptions of these species and populations have been based mainly on morphological and molecular data; how-ever, the characters related to the fish scales have not up to now been intensively studied and employed for the identifica-tion of the species belonging to this genus. The objective of this study is to test as to whether (i) scale surface morphology, (ii) scale surface microstructure, and (iii) scale size can be used to discriminate species and/or populations and, (iv) to discuss the possible causes of the observed differences. To achieve these objectives, scales of three species of the genus Aphanius from endorheic basins in SW Iran, viz. A. sophiae (nine populations from the Kor River Basin), A. farsicus (four populations from the Maharlu Lake Basin) and A. pluristriatus (a single population from the Mond River Basin) have been studied using SEM images, scale measurements, and uni- and multivariate statistics. It is opined that scale surface mor-phology and microstructure cannot help in distinguishing the species, but can be employed to discriminate certain popu-lations of A. sophiae (those from Safashahr, Kharameh, Tashk, Gol). In addition, scale size and J-indices, respectively, represent a valuable tool for species separation, which corroborates earlier studies for the use of these indices in taxonomy. Major driving forces of the differentiation within A. sophiae probably include habitat fragmentation resulting from the geological history and local adaptations. Thus the differentiation results from a balance between both genetic and envi-ronmental effects.

Morphologically similar populations of Aphanius that are currently considered as A. sophiae inhabit the endorheic Kor River Basin in the Zagros Mountains. Using genetic analysis based on mtDNA (cytochrome b), combined with examination of morphology (morphometry, meristics, otoliths), we discovered that what is thought to be A. sophiae is actually two distinct species, one of which is described as A. shirini sp. n. The males of the new species can be distinguished from those of all other Iranian inland Aphanius species by having only 7–10 clearly defined white flank bars, which is the lowest number of flank bars among the Iranian inland Aphanius species. Both males and females differ from all other Iranian inland Aphanius species by having a significantly longer caudal peduncle and a smaller dorsal fin depth. Based on the PhyML and Bayesian likelihood trees, A. shirini is sister to A. vladykovi from the Karoun Basin in the Zagros Mountains. Our results indicate that an ancient exorheic Kor River Basin existed in the Late Miocene and Pliocene. The close phylogenetic relationship between A. shirini and A. vladykovi suggests that the pre‐Pliocene drainage in the ancient Kor River Basin was directed to the north‐west (to the Karoun Basin), and not to the south‐east as in the present‐day Kor Basin. Both A. shirini and A. vladykovi represent the highest altitude records for Aphanius. We conclude that the splits of A. shirini and A. vladykovi can be linked to tectonic events in the Middle to Late Miocene, which created the highest altitudes (>3000 m) in the Zagros Mountains, and led to isolation of populations. The present‐day endorheic Kor Basin is known to have formed in the Late Pleistocene or Early Holocene, and the ‘young’ age of A. sophiae is clearly related to this history. Our results contribute to elucidate the link between geological history and the present‐day species diversity in the tectonically still active Zagros Mountains of Iran.

Two new species of Aphanius are described from the Kol drainage in southern Iran (Aphanius darabensis n. sp.) and the endorheic Kavir Basin in northern Iran (A. kavirensis n. sp.), and compared with eight closely related species. Aphanius darabensis n. sp. is sister to A. shirini, from which it is distinguished by molecular characters (cytochrome b) and the combination of three morphological characters: 9-18 flank bars in males (vs. 7-10), females with irregular vertical patches of brown color on the flank (vs. prominent dark brown blotches of round or irregular shape), and symmetrically-shaped triangular to trapezoid otoliths with a rostrum distinctly longer than the antirostrum (vs. quadrangular to trapezoid otoliths with short and equally sized rostrum and antirostrum). Aphanius kavirensis n. sp. is closely related to a group containing A. sophiae, A. mesopotamicus and A. pluristriatus, from which it is distinguished by cytochrome b characters and the combination of three morphological characters: females with irregularly arranged large blotches of dark brown color on the flank, short pectoral fin in both sexes (13.4-18.1% SL in males, 11.2-18.3% SL in females), and asymmetrically shaped triangular to trapezoid otoliths with a pronounced predorsal region. Our tree based on the cytochrome b data demonstrates that the Iranian inland and inland-related Aphanius species (IIRAS) form a monophyletic clade with three subclades (A. vladykovi -, A. shirini -, A. sophiae subclades). The A. sophiae subclade, which is the most diverse of the three subclades, can be further divided into three lineages (A. isfahanensis -, A. farsicus -, A. sophiae lineages). The temporal diversification of the IIRAS clade is discussed and two evolutionary groups of Aphanius are depicted. Aphanius vladykovi, together with A. shirini, A. darabensis n. sp. and A. isfahanensis characterize the "old" evolutionary group. Their divergences may have happened 10-5 m.y. ago (Late Miocene-Early Pliocene). Aphanius farsicus, A. arakensis, A. sophiae, A. mesopotamicus, and A. pluristriatus, together with Aphanius kavirensis n. sp., represent the "young" evolutionary group, which developed in the Late Pleistocene (100,000-11,700 y. ago) and Early to Middle Holocene (c. 11,700-4,000 y. ago).