AQUATIC PHYSIOLOGY AND BIOTECHNOLOGY
Year:2016 | Volume:4 | Issue:2|Papers Count:6

The objective of the present study was comparing some biological parameters including length, weight, age and sexuality of four species of genus Alosa (A. saposchnikowii, A. sapia, A. kessleri and A. braschnikowi) in coastal zone of Mazandaran province of the Caspian Sea. Monthly random samples were collected during October 2014 and April 2015 (249 samples). The highest total length (27.65±4.32cm) and body weight (262.05±172.25g) belonged to A.braschnikowi. There was a significant correlation between total length and body weight among four species ofAlosa (P<0.001). Sex ratio (male: female) of four species were 1.35: 1, 1.28: 1, 1: 1.4 and 2.38: 1, in respect to above mentioned order. Only the sex ratio of A. saposchnikowii (2.38: 1) was significantly different from the expected 1: 1 ratio (P<0.001). Gonadosomatic Index (GSI) among four species of Alosa was significantly different (P<0.05, F=4.04).Condition factor (CF) between four species of Alosa showed a significant difference (P<0.05, F=4.26). The results showed environmental compatibility of A. braschnikowi was better than other species.

Despite the expansion of nanotechnology in various industries, a proper evaluation of lethal concentration of nanoparticles on fishes has not been investigated. In present study, the toxicity of titanium nanoparticles was studied in juveniles of common carp and roach. For this study, 105 pieces of roach and common carp with total length of 5.46±0.57cm and 7.36±0.30 cm, respectively, were placed in 60L glass water tanks. According to the LC50 test, toxicity of titanium for common carp and roach were obtained as 12523.44±0.47 and 8693.37±1.96 ppm respectively. After 7 days of exposure to sub-lethal concentrations of titanium dioxide, blood samples were taken. The haematological indices showed significant decrease in red blood cells, hemoglobin and hematocrit values (P<0.05) exposed to sub-lethal concentrations when compared to the control group. The results of this study showed that titanium dioxide nanoparticles can have a negative effect on blood parameters and reduced the amount of red blood cells and hemoglobin content of blood which caused fish death.

Aquatic industrial waste is rich in protein and the best way to reach this organic material is using a protease enzyme. Therefore, the selection of a resistant protease from an aquatic species and using a suitable substrate for immobilization is very importatnt. In this study, the purified protease from shrimp Penaeus vanamei was immobilized on multi-walled carbon nanotubes (MWCNTs). After activating MWCNTs with nitric acid, in ordet to binding of enzyme to MWCNTs, enzyme solution with concentration of 7mg/mL was added to MWCNTs and incubated at 10oC for 4 hours. After three washing with phosphate buffer (pH 7.5), the nano-enzyme was dissolved in 1mL of phosphate buffer. Based on the results, the enzyme immobilizations on the MWCNTs enhance significantly the stability to temperature and extreme pH values. The optimum temperature of immobilized enzyme increased from 60 to 80oC and optimum pH did not change. The kinetic indexes of the enzyme (Km and kcat) changed during the immobilization. These results indicate that immobilized Penaeus vanamei protease on MWCNTs could be used for biotechnological applications due to the high stability.

Due to the superior role of silver carp (Hypophthalmichthys molitrix) in the carp polyculture system, this study was conducted to evaluate the effects of catching, handling and transportation on hematological and biochemical parameters of juvenile fish (13.5±1.5g). Hematological and biochemical parameters were measured before catching (without handling), during the catches and 1, 3, 6, 12, 24 and 48 hours after transportation. The biochemical parameters including cortisol, glucose and lactate had significant differences among treated fishes (P<0.05). The cortisol and glucose levels rose quickly since catching up to 12 hours after it and significantly decreased after 24 hours, but it never returned to the normal level. The highest and lowest level of lactate was observed during catches and coming 12 hours. Except monocytes, all hematological parameters including the number of white and red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, neutrophils and lymphocytes had significant differences among treated fishes (P<0.05). The amounts of hemoglobin and hematocrit were significantly increased 12 hours after fishes were caught (P<0.05). The results of hematological and biochemical parameters showed that catching and handling of juvenile silver carp had harassment effects on fish welfare and it is necessary to provide optimum conditions to reduce stress effects.

Conus frigidusis venomous predatory marine gastropod that is placed in Virgiconusclade of the coast of Qeshm and Lark. The species in this clade is morphologically similar and sometimes named wrongly. Therefore, their molecular identification is important. In this study, DNA was extracted by CTAB. The COI gene fragment was used as a barcode to identify the species.After amplification of the gene and its sequencing, phylogenetic trees were depicted using MEGA 6 and MrBayes 3.2 softwares. The results showed that the nucleotide sequence of COI gene fragment of C. frigidus, on the coast of Qeshm and Lark, have only differ in one nucleotide from the Indo-Pacific sequence of C. frigidus. Phylogeny tree of Virgiconus clade represents a dramatic difference of this species with other clade species. Therefore, it seems that the origins of C. frigidus of the Persian Gulf, was from the species from the east coast of the Indian and Pacific Oceans. Identification of species based on COI gene in the species is very useful and precise method when characteristics resemblances among species are high.

In this study, acetylcholinesterase enzyme activity in bivalve Mytilaster lineatus exposed to Deltamethrin sub-lethal concentrations in the lowest (0.5mg/L) and highest (1mg/L) concentrations, respectively, estimated 15.665±0.1291 and 11.912±0.4334mmol/min/mg protein. According to one way ANOVA results, enzyme activity in M. lineatus exposed to 0.5mg/L Deltamethrin did not show significant deference (P>0.05); but when exposed to 0.75 and 1 mg/L Deltamethrin significant effects was observed (P<0.05). At 0.75mg/L concentration of Deltamethrin inhibitory effects on acetylcholinesterase activity was shown which was continued by further increment in Deltamethrin concentration.