Iranian Journal of Ichthyology
Volume:1 Issue: 2, Jun 2014

More than 32 alien (exotic) fish species belonging to 10 orders and 12 families (Cyprinidae, Gobiidae, Salmonidae, Anguilidae, Mugilidae, Centrarchidae, Heteropneustidae, Gasterosteidae, Cichlidae, Poecilidae, Adrianichthyidae and Pleuronectidae) were reported from Iran of which 25 species are confirmed by specimens. Some of the alien fishes (e.g., Cyprinus carpio, Carassius auratus, Pesudorasbora parva, Xiphophorus hellerii and Gambusia holbrooki) have already established breeding populations, acting as invasive species. Some others are regularly stocked by the Iranian Fisheries Company (e.g., Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Ctenopharyngodon idella) and few others are occasionally recorded from natural waters. Amatitlania nigrofasciata and Tilapia zillii are two alien cichlids recently reported from Iran. Aquaculture, sport fishing, control of malaria, ornamental purposes, research activities, demonstration in national fairs and accidental introduction are the main reasons for these introductions. Pseudarasbora parva was introduced accidentally along with other exotic carps and now is widely distributed in inland waters. The intentional introduction of alien species is an extraordinarily complex issue and requires taking into account a broad number of variables. Understanding the risks that alien species, especially aquatic invasive species (AIS) pose, comparative studies on the ecology and life history strategies of the introduced and invasive species and closely related indigenous species with similar ecological life traits, monitoring the rate of invasion, and the causal relation between population dynamics and species invasion and public awareness, could be effective management strategies to minimize the bio-invasion impacts.

The osteology of the suspensorial and opercular series in representatives of 49 genera and 41 families of eurypterygian fishes were studied. The suspensorium consists of the palatine, ectopterygoid, endopterygoid, metapterygoid, quadrate, symplectic, and hyomandibular bones. The hyomandibular foramen is present at the base of the anterior head. The opercular series consists of the preopercle, subopercle, interopercle, and opercle. In most Eurypterygii, the preopercle is L-shaped and bears an open or closed preoperculomandibular canal.

Fish species diversity, distribution and abundance were studied in the Sardabrud and Chalus rivers, in the Southern Caspian Sea Basin, during 1992 and 1993 in five and four stations respectively, by monthly collections using electrofishing device. In total, 3200 fish specimens, including 15 species in Sardabrud River and 12 species in Chalus River, were investigated. The fish comprised of 13 genera and 5 families: Petromyzontidae, Cyprinidae, Cobitidae, Salmonidae and Gobiidae; the majority being Cyprinidae. This is the first report of Pseudorasbora parva in Sardabrud River. The Shanon’s index for Sardabrud River ranged from 0 to 1.77 and for Chalus River from 0 to 1.91. Fish species diversity was significantly correlated with altitude (r2= 0.96 and P

In this study, the systematic position of Acanthalburnus microlepis from Kura and Aras basins is clarified and some notes on the taxonomy of the Acanthobrama species distributed in Turkey are given. Based on the morphological and osteological analyses, a high similarity between A. microlepis and Acanthobrama members is found. Some taxonomic information yielded from the examination of recent collections from Dicle (Tigris), Fırat (Euphrates), Asi (Orontes), Ceyhan, Seyhan rivers and Berdan Stream near Tarsus is also included. Accordingly, Acanthobrama marmid is distributed only in Dicle-Fırat system (presumably also in Sinnap Stream from Kuveik Drainage) and the populations from Asi, Seyhan and Berdan Stream (Tarsus) regarded as a separate subspecies as A. marmid orontis Berg, 1949 should be considered full species according to phylogenetic species concept and Ceyhan population represents a new species.

It is postulated that building of Manjil and Tarik dams on Sefidrud River has led to morphological divergence of Siah Mahi, Capoeta gracilis of up-and downstream populations due to isolation. To test this, a total of 97 individuals of C. gracilis were collected from three sampling sites, including upstream of Manjil dam, upstream of Tarik dam and downstream of Tarik dam, in November 2013. A 13-landmark morphometric truss network system was used to investigate the hypothesis. Principal component analysis (PCA), canonical variates analysis (CVA), linear discriminant function analysis (DFA) and clustering analysis (CA) were used to examine morphological differences among the populations. Univariate analysis of variance showed significant differences among the means of the three groups for 48 standardized morphometric measurements out of 78 characters studied. In, DFA the overall assignment of individuals into their original groups was 77.8%. The PCA scatter plot of individual component scores between the first and second factors showed 97 fish specimens grouped into three areas but with a relativity low degree of overlap among the three populations. Cluster analysis indicating different populations of C. gracilis in up- and downstream Manjil and Tarik dams in Sefidrud River. The present study indicated the presence of morphologically different populations of C. gracilis in up and downstream of Manjil and Tarik dams in Sefidrud River, probably, is due to their limited downstream dispersal and elimination of upstream migration altogether, due to the construction of the dams.

This study was conducted to evaluate the morphological responses of two different species including Capoeta gracilis and Alburnoides eichwaldii due to construction of the Tarik dam in the Sefidrud River using geometric morphometric technique. For this purpose, a total of 80 specimens of C. gracilis and 60 specimens of A. eichwaldii were collected from upstream and down-stream of dam. The left sides of specimens were photographed and14 and 18 landmark-points were digitized on 2D pictures of and C. gracilis and A. eichwaldii, respectively. The landmark data were submitted to GPA to remove non-shape data, analyzed by discriminate functional analysis and Ttest hotelling. The results showed no differences between the upstream and downstream populations of C. gracilis, but a significant difference found in A. eichwaldii in terms of body shape. The observed differences were related to head, snout, caudal peduncle regions and eye diameter that could be an adaptation to altered habitat and hydrological conditions of upstream and downstream due to damming. Different response of two studied species displayed that fishes can respond in different way to anthropogenic modifications of riverine ecosystem.

One of the most important methods for evaluating changes in an ecosystems is studying the biodiversity changes. This study sought to examine the changes of biodiversity in two different fishing grounds of the Persian Gulf. For this purpose, two fishing grounds were selected, Abumusa, Tonb and Siri as subarea 1, and Kish westward as subarea 2. The catching data were obtained from two fishing vessels in January 2010 and July 2011. To evaluate changes in diversity of the populations, Simpson index, economic diversity index, Shannon index and the Hill index were used. The species diversity in subarea 1 was higher than that in subarea 2. The percentage of total frequency was higher for Tunnus tonggol (53.34 and 37.64) and Euthynnus affinis (40.76 and 27.34) in both subareas. However, the economic diversification index was higher in subarea 2 and the evenness index was higher in subarea 1.