IRANIAN JOURNAL OF ICHTHYOLOGY
Year:2017 | Volume:4 | Issue:1 |Papers Count:7

Nemacheilid loaches of the genus Paraschistura has been widely distributed from the Tigris drainage in Turkey, east throughout Iran and Pakistan to the Indus River and the Hari, Murghab and Helmand endorheic basins in Afghanistan, Iran, Pakistan and Turkmenistan. Herein, Paraschistura specimens from seven stations in Hari river basin were captured using hand-net and COI sequences of Paraschistura cristata and Paraschistura turcmenica were presented for all recognized species. Moreover; 119 sequences from ten species of Paraschistura in Genbank were added in order to assess of the phylogenetic position of the Paraschistura specimens and compare resulting tree with other studies. Molecular data obtained from Maximum likelihood (ML) tree and Bayesian tree (BI) were congruent and clearly indicate two main clades in phylogenetic tree and the genus Paraschistura in the Hari River basin, are considered as P. cristata and P. turcmenica.

The osteology of the caudal skeleton in representatives of 41 genera in 39 families of eurypterygian fishes was studied. The caudal skeleton of eurypterygian fishes consists of five or six hypurals, a parhypural, one to three epurals, one or two pairs of uroneurals, ural centra 1 and 2, last preural centra and associated neural and haemal spines, and procurrent and principal rays. Eurypterygians like other teleosts have a diural caudal skeleton (two ural cen-tra). Primitively in basal Acanthomorpha and Acanthopterygii, the caudal elements are autog-enous and several intercaudal and postcaudal cartilages support these isolated elements. Basal groups usually have six autogenous hypurals, three epurals, two pairs of autogenous neurals, autogenous ural centrum 2, and autogenous haemal and neural spines on the last centra. In some basal groups such as Myctophidae, many of the caudal elements are fused, because of the presence of primitive conditions in related taxa, the fusion in such a groups should be re-garded as secondary and independent from that in higher taxa. In higher groups, there is a tendency for the elements to fuse together and to the centra and caudal cartilage are lost due to lack of function. In specialized groups such as some Scorpaeniformes, all the elements are fused and the caudal cartilage is lost.

Recent development in the nanotechnology industry and increase in the number of products manufactured by nanoparticles has inevitably contributed to the discharging of nanomaterials into the aquatic ecosystems. To improve the harmful effects of these toxic materials diverse complements like dietary nucleotides (NT) have been proposed. The effects of dietary NT on silver bioaccumulation in gill and muscle tissues were described after exposure to various concentrations of water-borne silver nanoparticles (AgNPs) and/or silver nitrate (AgNO3) in the present investigation. Specimens of striped catfish, Pangasianodon hypophthalmus, were divided into two groups fed with two different diets (control and NTsupplemented 0. 75%) over a period of 10 weeks and were subsequently exposed to various concentrations of AgNPs and AgNO3 under static-renewal conditions for 10 days as follow: 1μ g/L AgNPs, 1μ g/L AgNO3, 20μ g/L AgNPs and 20μ g/L AgNO3. After the exposure period, samples of gill and muscle tissue were taken to measure silver bioaccumulation via atomic absorption spectrometry. Silver bioaccumulation in gills was about 5-10 times higher than those measured in the muscles. By increasing silver concentrations in the water, its accumulation in the tissues increased significantly. Generally, AgNO3tended to accumulate more than AgNPs in both tissues and all used concentrations. Fish fed on dietary NT showed lower silver accumulation levels in both tissues; although, the lower accumulation was more clear in gills in comparison to the muscles. It could be concluded that adding NT to the diet of striped catfish could significantly boost the fish defense against silver accumulation, but it is recommended to do some detailed studies to find out its mechanism.

Cytological status of ovarian activities in Gudusia chapra (Hamilton, 1822) were studied during different phases of reproduction. An asynchronous development was observed in the ovaries. Variations in the ovary weight and gonadosomatic index (GSI) were also observed. Diameter of oocytes were investigated during growth, maturation and spawning phases. It was further revealed that peak of spawning period was during March to April, with a second spawning time in July.

This study was conducted to evaluate the effects of purple coneflower (Echinacea purpurea) (EP) on growth and blood parameters in juvenile sterlet (Acipenser ruthenus). One hundred and eighty fish (mean weight 75± 1SDg) divided into 12 tanks (n=15) after adaptation period. Base diet was supplemented with 0 (control), 0. 5, 1 and 2g/Kg EP to formulate experimental diets. Fish were fed daily at a rate of 3% of body weight. After 60 days, all fish were weighted for growth analysis and blood samples were collected to assess hematological parameters. Results showed that growth indices were not significantly affected by EP extract (p>0. 05). There was no notable differences in hematological parameters, including red blood cell, white blood cells, hemoglobin, lymphocyte and neutrophil percentage in treatments compared to the control group (p>0. 05). Total protein, albumin, globulin and albumin to globulin ratio did not reveal any differences between experimental and control groups (p>0. 05). Lysozyme and Immunoglobulin M in fish fed with EP were higher, compared to the control group (p<0. 05). It could be concluded that diet supplementation with EP improved immune system function in A. ruthenus, but had no effect on growth in this species.

This study aimed to examine the effects of Chlorella vulgaris (CV) on the hematological and immune parameters of Koi carp (Cyprinus carpio). An experiment was designed with five treatments, including diets with 0, 2, 5, 7 and 10% of C. vulgaris each with three replicates for 8 weeks. At the end of experiment, the hematological and, immune system parameters were measured and analyzed. The results revealed that supplementation of C. vulgaris in diets resulted in higher percentage of haemoglobuling (Hb), haematocrit (Hct), red blood cells (RBC) and white blood cells (WBC). In addition, a significant increase in the levels of IgM, lysozyme and C4 complement levels were found in fish fed CV at different levels showing a positive effect by this microalgea on the immune status of Koi carp. Based on the results, supplementation of CV particularly at 5% of its dry powder in diet of Koi carp can play an important role in the stimulation of fish immune system.

In this study, presence of the snapper, Lutjanus indicus Allen, White & Erdmann, 2013 (Lutjanidae) is reported for the first time from the Visakhapatnam coastal waters, East coast of India and detailed characteristics of the collected specimens (158-296 mm SL) are provided. In addition, significant color differences, especially a series of eight narrow yellow to brown stripes on the side, obliquely rising dorsally and posteriorly on body which are useful for separating the two closely related congener species (L. indicus and L. russellii) are presented. Here, we confirm the occurrence of Lutjanus indicus in Indian coast and extend the range of the occurrence of this species to Bay of Bengal.