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Shirbot (barbus grypus) belongs to Cyprinidae family and it is considered as one of the most important commercial species in Iranian aquaculture. It has a large presence in the west and southwest water resources of Iran specially Khuzestan Province rivers. However, there is lack of cellular information about this species. In this study, the genetic structure of barbus grypus from Dez and Karoun regions was investigated by 7 polymorphic microsatellite loci. According to the results, the Fst value was 0.025 which indicates the low genetic differentiation between the populations. In Hardy-Weinberg equilibrium investigation, most of the loci showed deviation from equilibrium. The number of alleles, observed and expected heterozygosity were, 7-20, 0.16-1(the average: 0.7) and 0.736-0.933(the average: 0.856), respectively. This indicates the allelic diversity and genetic variation of investigated populations is at favourable level. Also, analysis of molecular variance showed there is low genetic variation among populations and most of the observed variation is within the populations. Results derived from genetic distance indicated that Shirbot populations are separate from each other in the investigated regions.

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To determine genetic diversity of Paracobitis hircanica in Tilabad, Touskestan and Zaringol rivers of Golestan province, six microsatellite markers were utilized all of which showed polymorphism. Investigation of genetic differentiation revealed the Fst of 0.028, indicating low genetic differentiation among the samples of the studied regions. Also, investigation of Hardy-Weinberg equilibrium showed significant deviation from Hardy-Weinberg equilibrium in 16 samples of 18 tests of population-loci mostly due to the observed heterozygosity deficiency. The number of alleles and observed heterozygosity was 8-16 (the average of 11.94) and 0.03-1/00 (the average of 0.52), respectively, which are slightly higher than the amount reported for fresh water fish. Results indicated that P. hircanica has high allelic richness and considerable genetic diversity in the investigated regions. Additionally, analysis of molecular variance revealed that most of the observed diversity was within populations and there is low diversity among the populations. Results from genetic distance represented that there is probably separate populations of P. hircanica in Golestan Rivers

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This study was carried out to identify the taxonomic composition of fish larvae collected bimonthly in waters of Bushehr to Genaveh in six stations (Five creeks: Shif, Lashkari, Ramleh, Farakeh, Dubbeh, and one station in the seashore) in norhtern Persian Gulf, Iran, from June 2013 to April 2014. Fish larvae were sampled usinga Bongo-net (diameter, 60 cm; mesh size, 300 µm).A total of 21440 fish larvae representing 30 families (which included two subfamilies, eightgenuses, nine species and eight types), one group to the levels of order and two types were recognised. The identified taxa were: Apogonidae, Blenniidae, Callionymidae, Carangidae, Clupeidae, Cynoglossidae, Diodontidae, Engraulidae, Gerreidae, Gobiidae, Haemulidae, Hemiramphidae, Leiognathidae, Mugilidae, Mullidae, Nemipteridae, Pegasidae, Platycephalidae, Scatophagidae, Sciaenidae, Scombridae, Sillaginidae, Soleidae, Sparidae, Sphyraenidae, Synanceidae, Syngnathidae, Terapontidae, Triacanthidae, Tripterygiidae, and Tetraodontiformes. Among them, Soledae (including 6 types) and Gobiidae (including 3 types) were the most diverse families. What is more, Pegasus volitans (Pegasidae), Cyclichthys orbicularis (Diodontidae), Trachurus indicus (Carangidae), and Hippichthys penicillus (Syngnathidae) were reported for the first time in Iranian waters.

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Golden grey mullet, Liza aurata, is a non-endemic species with high commercial value in the Caspian Sea. This species showed sever mortality during recent years due to viral nervous necrosis. In the present study, six microsatellite loci (Mcs16Em, Mcs15Am, Muso10, Muso19, Muso22 and Muso27) were used to assess and compare the genetic structure of golden grey mullet in Gharesou and Gomishan regions (28 samples for each region) as well as dead samples from Gharesou region (28 samples). The polymorphism was observed in all loci. In the study of genetic diversity indices, the mean number of alleles and observed heterozygosity were obtained as 14.33 and 0.82, respectively. In addition, no significant difference of allelic diversity and heterozygosity was also observed between studied samples. 10 out of 18 tests showed significant deviation from Hardy-Weinberg equilibrium. The average amounts of inbreeding (Fis), genetic differentiation (Fst) and gene flow (Nm) indices were obtained as 0.07, 0.033 and 8.40, respectively. Furthermore, the lowest genetic distance and the highest genetic similarity were observed among the samples of Gomishan and Gharesou in that according to UPGMA dendrogram based on genetic distance, the samples from Gharesou and Gomishan were considered as a separate group from the dead samples. 

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Kutum (R. kutum) is regarded as the most important commercial bony fish in the southern Caspian Sea. Restocking of this fish is done by releasing the larva produced by artificial propagation. In the present study, genetic diversity and structure of wild populations (caught in Gorgan bay and Gomishan wetland) and hatchery population used for restocking were investigated and compared using ten microsatellite loci. The microsatellite loci showed high polymorphism. The mean number of alleles was 9.4, 8.9 and 8 for Gomishan wetland, Gorgan bay and hatchery samples, respectively. The mean observed heterozygosity was 0.80 for Gomishan wetland samples, 0.798 for Gorgan bay samples and 0.728 for hatchery samples. Despite the lower levels of allelic diversity and heterozygosity of hatchery samples, no significant difference was observed in this respect. Twenty six cases out of 30 tests showed significant deviation from Hardy-Weinberg equilibrium. Moreover, high deficiency of heterozygosity was observed in some of loci. The mean values of Fst and Rst as the indices of genetic differentiation were obtained 0.018 and 0.044 respectively indicating low differentiation between the samples. The highest value of genetic distance was observed between Gorgan bay and hatchery samples. According to UPGMA dendrogram, the wild samples were separated from the hatchery ones. According to the obtained results, wild populations of Kutum had proper allelic and gene diversity in the investigated regions. However, considering the persistence of restocking programs by artificial reproduction, it is necessary to establish appropriate strategies to maintain and improve the observed diversity in wild populations.

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The present investigation considered retina structure in embryos, larvae and adult Alburnus chalcoides. Histological samples of retina were provided from adult fish, different stages of embryonic and larval development. Eye primordia formed from ectoderm at 16 hours after fertilization (16hAF) and then developed to eye cups. Initial eye cup which contained undifferentiated retina began to form before 26hAF. Epithelial pigmented cells were first to be distinguished from other cells at 36hAF where as pigmentation initiated by delay at 68hAF. Larvae were hatched with undifferentiated retina at major part (~72hAF). First distinct stratification was observed at 96hAF (1DAH) with 5 strata including: retina pigmented epithelium, photoreceptor cell layer, inner nuclear layer, inner plexus layer and ganglion cell layer. At 144hAF (3DAH) outer plexus layer was distinguished. The stratification was completed at early 4DAH when photoreceptor cell layer divided into two layers i.e. outer plexus layer and photoreceptor layer,. Retina was stratified completely before yolk sac depletion was completed at late 7DAF. The strata order in adult was similar to 4DAH larva, but its thickness was different. As inner nuclear layer thickness was decreased but photoreceptor layer thickness was increased.
 

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The zinc element (Zn) is one of the micronutrients and an essential element of the body which has some deleterious and irreparable effects on growth in case of lack it. Thus, we aimed to assess IGF-1 in goldfish with Zn deficiency and to investigate the effect of Zn supplementation on these parameters. Goldfish  (Carassius auratus)  juvenile  (3.5 g)  were fed purified diets based on casein as a protein source and containing different levels of supplementary zinc sulfate (0, 25, 75 and 150 mg ZnSO₄/kg diet) for 60 days. The results showed that fish fed with a diet supplemented with 150 mg kg^-1 Zn had a significantly (P < 0.05) greater specific growth rate and lower feed conversion ratio than those fed with the diets of 0, 25 and 75 mg kg^-1 ZnSO₄. The results revealed that administration of zinc sulfate significantly (P < 0.05) up regulated Insulin-like growth factor-1 (IGF-1) gene expression. IGF-1 gene expression was significantly (P < 0.05) higher in zinc sulfate fed fish at the end of trial. Collectively, our results indicate that ZnSO4 stimulates Insulin-like growth factor-1 secretion from the liver at the post-transcriptional level.
 

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The present study examines the developmental stages of the eye retina in Caspian kutum during the pre-hatch stage to end of the larval stage. Fertilized eggs of Caspian kutum were obtained from Shahid Ansari Center for Reproduction of teleost fish (Guilan province, Iran). Sampling was done for one month until the larval stage completed and the yolk sac completely depleted. Samples were studied by optical and electron microscopy. On day3 (68hpf) post fertilized embryo the primary optic structure was observed. The undifferentiated neural epithelium was placed around the lens placode originated from ectoderm. At (120hpf) 5dpf, the eye was spherical and the optic cup was formed. The first retinal stratification was initiated at the (216h.dpf) 9dpf and  cone cells appeared in the retina, while rod cells that only function in low light conditions, appeared after hatching at the fourth post hatching day. Cellular arrangement continued until several days after hatching. Along with the growth and development of the eye, the lens grew by addition of secondary lens fiber cells proliferated from lens epithelium cells. Also the primary lens fiber losing nuclei and other membranous intracellular organelles. The results obtained from the diameter of the lens and the cone density represented that visual acuity of Caspian kutum larvae increased at the end of larval stage.
 

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In this study 12 specimens were collected from Bandar Jask, Qeshm Island and Bandare Lengeh in Hormozgan Province. DNA extraction was performed using Phenol-Chloroform method. A partial DNA sequence of Cytochrome oxidase subunit I gene (COI) was used to evaluate genetic diversity. The sequence of Cytochrome oxidase subunit I gene was done using specific primers designed based on sequences registered in NCBI GenBank. The diversity of 619 bp of COI was estimated. Gene sequencing of samples were compared with using MEGA5 and Bioedit7 software. Also, polymorphism or haplotype frequency was evaluated using dnaSp7 software. Results showed that there was low genetic distance equals to among all population and 9 haplotypes among samples were determined.