---

Kura bleak, Alburnus filippii, a member of the family Cyprinidae, is found in the rivers of Aras and Sefidrud, and the Anzali lagoon of Iran. The current study was conducted to provide a detailed osteological description of this sp-ecies since there was not adequate information in this regard. In order to attain this goal, 20 specimens were collected from the Ahar Chay River by electrofishing device, and fixed in 10% buffered formalin. The specimens were cleared, stained with alizarin red S and alcian blue for osteological examination and a detailed description of its skeletal structure was provided. The results showed that this species can be distinguished from other members of this genus in Iran by a combination of osteological characters, including having pointed process of the maxillae, dorsal tilting of the coronoid process, protruding of the anterior margin of the hyomandibular, fan-shaped anterior part of the basihyal, pointed end of the pre-vomer posteriorly, small fourth infraorbital and 11 pterygiophors in the dorsal fin.

---

This study was conducted to understand the morphological variation of four populations of Schizothorax pelzami from Iranian inland waters. For this purpose, a total of 81 specimens were collected from the Bidvaz, Cheshmeh-Ali, Kalat and Aal rivers. After anesthesia, all specimens were fixed into buffered formalin and transferred to the laboratory. Then, the left sides of all individuals were photographed. To extract the body shape data, 14 landmarks-points were defined and digitized on 2D image using TpsDig2 software. To eliminate size, direction and position from data, the Generalized Procrustes Analysis (GPA) was performed. Then, PCA, MANOVA/CVA and cluster analysis were used for further investigation. The results showed that there was no significant difference but some overlapping among the studied populations on the basis of PCA analysis was observed. The CVA graph separated the studied populations from on another. The main differences in body shape of the studied populations were related to the position of the snout, the depth of head and body, and the length of caudal peduncle. The observed changes can be considered to be an adaptation to their habitat, which has been influenced by different environmental parameters.
 
 

---

 
Atta Mouludi-Saleh¹, Soheil Eagderi¹, Keyvan Abbasi² & Manoochehr Nasri^3
1Department of Fisheries, Faculty of Natural Resources, University of Tehran, Karaj, Iran; ²Inland Waters Aquaculture Research Center, Iranian Fisheries Sciences Research Institute, Agricultural Research, Education and Extension Organization, Bandar Anzali, Iran; ³Department of Fisheries Science and Engineering, Faculty of Agriculture and Natural Resources, Lorestan University, Khorramabad, Iran
Correspondent author: Soheil Eagderi, soheil.eagderi@ut.ac.ir
 
Abstract: Due to the presence of taxonomic ambiguity regarding Petroleuciscus ulanus and Alburnus atropatenae and the tendency to treat them as synonyms of each other, this study was conducted to validate these two species by comparing their morphometric and meristic characters in the Mahabad-Chai River, Urmia Lake basin. A total of 64 specimens of P. ulanus and 68 specimens of A. atropatenae were sampled and were then investigated for 17 morphometric and 7 meristic characters. Measurements were standardized to eliminate the effects of size due to allometric growth pattern, then their normality and abnormality were examined. Standardized data were analyzed using t-test, Mann-Whitney, principal component analysis (PCA) and discriminative function analysis based on P-value of Hotelling's t-test (DFA/Hotelling's T-test) methods. The results showed that the two species were significantly different in 11 morphometric and 2 meristic traits (P<0.05). DFA analysis also showed significance differences between the two studied species. Our results refute the synonymy hypothesis of Petroleuciscus ulanus and Alburnus atropatenae on the basis of morphometric and meristic traits. Therefore, based on the results of this study, the taxonomic identities of these two species are valid.
 

 

---

Gambusia holbrooki Girard, 1859 is considered as one of the non-native and invasive species in the inland waters of Iran. This species occurs in most inland basins and aquatic bodies of Iran and has even been found in brackish waters. Extensive adaptations of this species to its different habitats caused numerous changes in its biological characteristics and morphological traits. The present study was performed to investigate the sexual dimorphism of G. holbrooki in the Gamasiab River, Kermanshah Province, Iran. 59 fish specimens were collected from the river in September 2017. After taxonomic confirmation and sex determination, 29 morphological traits were measured in fish samples using a caliper and their meristic traits were recorded. In total, 37 characters (including 8 meristic traits and 29 morphometric traits) were examined. After obtaining morphological data, Principal Component Analysis (PCA) and Discriminant Function Analysis (DFA) were utilized to compare morphological traits between male and female individuals. The results showed that the 59 specimens were comprised of 30 malea and 29 femalea. On the basis of the results, all morphological traits, except the caudal peduncle length, dorsal fin base length and a post-anal length, showed significant sexual dimorphism (p <0.05). The results of DFA and PCA analysis showed that males and females were completely different from each other in terms of morphometric traits. These findings indicate that there is a sexual dimorphism in G. holbrooki of the Gamasiab River. The sexual dimorphism observed in this fish species is due to the sexual selection and increase of reproductive success.

 

---

This study was conducted to investigate the ecological niche overlap of two sympatric species, Paracapoeta trutta and Capoeta damascina in the Iranian part of the Sirvan River, Persian Gulf basin. For this purpose, during the winter of 2021, sampling was done from eight stations (each with three repetitions). After identification, samples were released into the same sampling sites. Then some 10 environmental factors including depth, water velocity, river width, pH, temperature, electrical conductivity (EC), total dissolved solids (TDS), Altitude, slope, and dissolved oxygen were measured and recorded. Investigating the habitat suitability indices of P. trutta  were recorded as pH 7.5-8, temperature about 10°C, TDS 150mg/liter, EC 400μS/cm, altitude 1150 m, depth 15cm, river width about 9m, velocity 1 m/s, slope 2% and dissolved oxygen 9mg/l and for C. damascina as pH 6-6.5, temperature about 10°C, TDS 180 to 200mg/l, EC 300μS/cm, altitude 1150m, depth 25cm, river width about 6m, velocity 0.5 m/s, the slope is 2% and the dissolved oxygen 8mg. The results of the ecological niche overlap showed that two species based on studied environmental factors had the highest overlap value for dissolved oxygen (0.646) and the  value for temperature (0.293). The average ecological niche overlap was 0.432 for the two species.