سمیرا ناظم رعایا

Continuous monitoring and evaluation of surface water quality is necessary to protect the global ecosystem and human health. One of the most critical ways to estimate water quality is the WQI method. In order to check the water quality of the Maroon Dam lake located in Khuzestan province (15 km from Behbahan city), five sampling stations were selected at the inlet, outlet and inside of the lake. Sampling to measure the water temperature factor (with intervals of five meters by five meters from the surface to the bottom of the lake) and other factors such as dissolved oxygen, pH, biochemical oxygen demand, total phosphorus, total nitrogen monthly and from the surface to a depth of 60 meters (with distances of 20 meters by 20 meters) were carried out from October 2014 to September 2019 and finally the WQI index was calculated using qualitative parameters. The results of this study showed that the trend of changes in WQI index in different months of sampling in different stations in the quality class was medium to relatively good and the range of changes of this index was calculated between 49 in June to 66 in October. The depth measurement of temperature showed that in the lake behind the dam thermal stratification was created in spring (0 to 20 meters), summer and autumn (0 to 40 meters), but in winter, there is no such difference between surface and depth. According to the evaluation of the WQI index values of the reservoir water, it is suitable for all kinds of drinking purposes for domestic animals, agricultural purposes and raising resistant species of fish.

This study aimed to compare reproductive indices of broodstocks between and within (control and selected treatments) four different populations common carp of Hungarian-originated (TATA), North Iran, China-originated (RAN), and South Iran (Khuzestan). Control and selected treatments in each population comprised the average of the broodstock population and those chosen deliberately from 30% above the population mean (apart from shooter fish with excessive growth and out of the normal range), respectively, to calculate the genetic progress. Male and female reproductive indices were checked respectively by evaluating sperm quality (spermatocrit, sperm density per milliliter, percentage of motile sperm, and motility duration) and measuring working and relative fecundity, ovum and hydrated egg diameter, fertilization rate, hatching rate, the larval survival rate, and larval size after hatching. The results showed that, despite the high fecundity in the South Iran population, it has the lowest egg diameter and larval survival rate (p<0.05). Although the China-originated (control and selected treatments) population had the lowest sperm volume, sperm density per milliliter, and percentage of spermatocrit among different populations, the selected-treatment had the highest motile sperm percentage and the motility duration, which resulted in the most elevated fertilization rate belonging to it (p<0.05). The highest survival rate 24 hours post-hatching was observed in China-originated (control and selected) and North Iran-control, and the lowest in TATA (control and selected), North Iran-selected, and South Iran populations (p<0.05). China-originated control population gained the highest larval survival rate 72 hours after hatching. Although it did not differ significantly with the North Iran (control and selected) and TATA-control (p>0.05) populations, it has meaningful difference with the South Iran, TATA-selected, and China-originated-selected (p<0.05). The larval size in TATA-selected, North Iran-control, and South Iran is significantly smaller than other populations (p<0.05). There is no considerable difference in larval length size of the North Iran population between the control and the selected treatments, but it is significantly more in control than selected treatments in the China-originated and TATA populations. This finding illustrated that the selective breeding of broodstocks did not affect the reproductive indices within populations and the larval survival rate in F1. However, it improved the larval size. China-originated and North Iran populations performed satisfactorily in male and female reproductive indices, respectively, and it is worth bringing into mind hybridization between the two populations in future studies.

This study aimed to evaluate the effect of diets containing the white-button mushroom powder (WBMP) on growth performance and some hematological and biochemical indices of juvenile Persian sturgeon (Acipenser persicus). For this purpose, one hundred fifty-three juvenile of Persian sturgeon (47.78 ± 0.39 g) were distributed into nine experimental fish culture tanks with a total volume of 500 liters, filled with 300 liters of water. The fish were fed with diets containing 0.5% white-button mushroom powder (T1), 1% white-button mushroom powder (T2) and 0% white-button mushroom powder (control) as experimental diets for eight weeks. At the end of ‎the experimental period, no significant differences were observed in growth and feed‏ ‏utilization parameters between treatment and compare to the control diet (p>0.05). ‎Hematological parameter such as number of white blood cells was significantly ‎lower in the fish fed with the diet containing 1% WBMP compared to the control diet (p<0.05). The neutrophil percentage was significantly ‎higher in the fish fed with the diet containing 0.5 % WBMP compared to the control diet (p<0.05) as well. MCV, MCH, RBC, Hb, Hct, MCHC, lymphocyte, and monocytes were not different among the treatments (p>0.05). WBMP supplementation significantly increased serum glucose and cortisol in T1 and T2 (p<0.05). The current study results reveal that supplementation of diet with 0.5 and 1% WBMP causes negative effects on some blood and stress indices in juvenile Persian sturgeon. It seems that more studies are needed to determine the role of WBMP in sturgeon health and nutrition.

Bacterial diseases are a major challenge and warning to the development of aquaculture industry. Vibriosis is caused by bacteria of the genus Vibrio, especially Vibrio alginolyticus, in warm and temperate regions, which cause severe damages to the marine fish production economy every year. The aim of the present study was to isolate and identify this bacterium from farmed marine fish with bacterial septicemia symptoms in the farms of the southern provinces of the Iran. A total of 130 fish were sampled and isolated bacterial samples by conventional methods. Isolates were examined for biochemical and molecular properties using specific primers of 16 S rRNA and Collagenase genes to identify Vibrio sp. and alginolyticus species by polymerase chain reaction, respectively. Molecular analysis showed that 109 isolates out of 119 suspected isolates of Vibrio genus were confirmed as Vibrio genus; also, 48 isolates belonged to V. alginolyticus. It is concluded that the cause of more than 44% of cases of vibriosis is caused by infection with V.alginolyticus. For the LD50 determination, 250 Asian sea bass were used and the lowest LD50 calculated for Vibrio alginolyticus isolates was 1.83× 10 8 fish/CFU. The results showed a significant role of vibriosis as well as a high percentage of V. alginolyticus in bacterial septicemia in the studied fish.

Regarding the importance of aquaculture industry development, it is necessary to focus on inbreeding in artificial propagation to prevent genetic diversity reduction and problems arising from low genetic variation. Indeed, lack of facilities and the rules related to the responsible transportation of live aquatic animals, and carelessness on health- diseases control in farms has led to some diseases outbreaks which have imposed high costs for farmers, including huge losses or cure. Therefore, it is required to identify the species and population traits before initiating any culturing or breeding programs and evaluate them with molecular genetic methods to synchronizing study with biological characteristics such as reproductive potential, growth rate, and mortality. Achieving broodstocks and fry owning genetically relatedness is a principal issue in each hatchery. This article tries to discuss the significance of genetic diversity assessment by microsatellite marker for broodstocks' genetic relatedness, with an emphasis on Asian sea bass.Keywords: diversity, pedigree, Asian sea bass, marker

This study aims to assay the main protease (pepsin and trypsin) activity and pepsinogen relative gene expression, as well as histological development of digestive tract in Sobaity from hatching up to 40 days post- hatch (DPH). The results showed that exocrine pancreas, including zymogen granules, differentiated during yolk sac absorption and further developed at 14 DPH. The early appearance of trypsin before mouth opening is attributed to a genetically programmed process. The trypsin activity showed fluctuated pattern (with two peaks at 16 and 30 DPH), coincident with food intake, and related to diet shifting during larval feeding. The most obvious differentiation in the digestive tract was the formation of an incipient stomach surrounded by striated muscle fibers and the development of the gastric glands at 12 DPH. The stomach fully developed at 25 DPH with the transition from striated to smooth muscle cells. The pepsinogen relative gene expression was not detectable before 12 DPH and meaningfully detected at 14 DPH. The pepsinogen expression augmented exponentially coinciding with shifting diet from live to microdiet. Pepsin activity trend was considerably parallel to pepsinogen and started two days after pepsinogen, subsequently increased sharply during the weaning period (25-30 DPH) up to the end of the study. The study concluded that the appearance of the incipient stomach at 12 DPH, early pepsinogen expression, and ontogenetic development of pepsin and trypsin, make it possible to feed Sobaity larvae by inert diet before 25 DPH to reduce the live food consumption and improve the weaning efficiency.

By increasing the world population, agriculture development as a trustee of human food suppliers has more importance, so the extension plays a serious role as the link between research and the field. Aquaculture is the knowledge-, technology- and skill-demanding business that requires extension services for capacity development of human resources. The producers’ training in increasing raw products productivity and marketing are some of the key roles in promoting fishery products. Preparing paste and smoked products, different kinds of fillet and packaging which help in maintaining the quality and easy to use of fish are some of the main processing methods for improving fishery product marketing. This study aims to introduce silver carp’ value-added product including high-quality fillet, smoked fillet, fish ball, and fish burger in Ahvaz city, and then assessing the people’s feedback to these products. The results of completed questionnaires indicated that more than 70% and 50% of responders were satisfied of pastry product (fish ball and fish burger) and silver carp hot smoked fillet, respectively. Moreover, the most satisfaction (60%) among raw products belonged to silver carp minced toward fillets. The results of this study anticipate the bright future for the processing industry in Khuzestan province. Also, the importance of extension is highlighted in the opening up of products to different classes of people.

In this article, it tries to highlight the importance of the ornamental fish species industry in the world and Iran. It implicates the gene transfer method being able to produce aquarium fish species possessing special characteristics. Then, a variety of genes and promoters which can create colorful aquarium fish are defined. Finally, we recommend that researchers use the gene transfer biotechnology to produce worth and more attractive aquarium fish species because the ornamental fish are not for food purpose and the potential of producing ornamental fish is present due to species diversity and breeding center in Iran.

Prebiotics are non-digestible food components that are fermented by specific members of intestinal bacteria in the host gut, providing health benefits for the host. These components have received particular attention in aquaculture. They act via various mechanisms, such as changes in bacterial communities, end-products of prebiotics fermentation, preventing pathogen adhesion to host cells, modulating the immune systems and effect on gut morphology. In the last years, a large number of studies have reported positive effects for the use of prebiotics in fish. This article concentrates on prebiotics’ potential as functional components as well as their known mechanisms of their action. In addition, a number of studies on prebiotic beneficial effects in marine fish aquaculture as one of valuable source to supply protein demands have been reviewed. It seems factors such as prebiotic dosage, age, size, species, water temperature and duration of administration are influencing prebiotic mode of action.

Aquatic transgenic organism is an organism with a foreign gene or non-coding deoxyribonucleic acid (DNA) fragment is artificially introduced and stably integrated in their genomes. Since the first report in 1985, a wide range of transgenic fish and marine bivalve mollusks and crustaceans have been produced by microinjecting or electroporating homologous or heterologous transgenes into newly fertilized or unfertilized eggs and sperm. For producing transgenic organism many factors has been included. The first and the most important factor is aquatic species for gene transfer. In species selecting for gene transfer the target of research and species preservation with a high safety conditions and facilities should be concerned. The second factor is construct of target gene should be programmed for make it and need for these studies. For example gene construct in gene transfer method should have open reading frame of gene target. Also gene construct should have regulatory factors for regulating stable or transient gene expression or affect growth and development in organism. In the third step, recombinant construct should be transfer into sperm or embryo for stable gene expression. In the end stage, individuals received target gene should be traced. in addition, application of transgenic technology for producing  transgenic fish and other aquatic organisms with beneficial traits such as somatic  body growth, resistance to diseases and producing useful product for human, domesticated animal, poultry and aquatic organisms  have been increased by biotechnology.

One of the principal problems in marine fish larval rearing which includes financial loss is related to increased mortality in the stage while larvae have to shift feeding on formulated from live food. The reasons for applying weaning are high production costs, increased bacterial load and unreliable nutritional value of live foods. The commercial dry feeds can address this concern and decrease the larval production costs and consequently generate a highly profitable investment. In this paper, it was tried to consider recommendation which helps the aquaculturists to pass this larval stage successfully. Attention to the larval development stage, larval behavior, feeding strategies and considering the factors such as effective health management and monitoring the environmental conditions which affect the success of this change are met to discuss.

Regarding increasing the world population, the marine aquaculture will play a key role in supplying the protein requirement of the human. Therefore, the need for achieving to more production in this industry is necessary and unavoidable. Larvae and fry production also depend on broodstocks, while one of the major bottlenecks in marine fish breeding is to prepare gene pool of breeders having special genetically characteristics. These brood stocks may carry specific genes such as higher growth rate ability or resistance to disease. Since the conventional breeding is a long time and expensive protocol, applying the modern biotechnologies such as transgene would lead to achieving selective broodstocks. In this paper, it tries to introduce successful examples of transgenic marine fish produced worldwide. Moreover, it involves discussion about the important genes transferred to fish leading to raised production, reduced costs, and consequently more profitable investment.

This research was conducted to study the body shape changes and morphological development of spare Sobaity (sobaity sea bream) (Sparidentex hasta), a valuable economical species, during early development from hatching up to 35 days post hatching (DPH) using geometric morphometric technique. A total number of 531 larval specimens were collected from different days. For extracting body shape data, the left side of specimens was photographed. Then nine homologous landmark-points were defined and digitized on 2D pictures using tpsDig2 software. Landmark data after GPA, based on procreates analysis analyzed using Relative Warp. The results showed that change of body shape in spare Sobaity during early development includes increasing depth and length of head, development of caudal region and increasing body depth, respectively. The cluster analysis was performed based on body shape of larval specimens using Ward’s algorithm, to identify clusters between age or size groups and the results revealed that larval stages of Sobaity can be divided into five stages including (1) early larvae, (2) larvae, (3) post larvae, (4) younger juvenile and (5) juvenile. Also, based on our finding, the body shape changes of this species during early development is due to adjusting of vital priority.

In this study، the possibility of early weaning and its effect on growth، survival rate and quality of Sobaity Sea bream (Sparidentex hasta) larvae from 25 (control group) to 18 (treatment group) days post hatch (DPH) were investigated. For growth rate measurement، sampling was done prior to starting test on 0، 2، 4، 10، 14، 16، and 18، and afterward on 25، 32 and 39 DPH; and for survival rate، cannibalism rate and also larval quality on 39 day post hatch. The result showed that thought from the starting of weaning to the end of rearing، the Specific growth rate (SGR) was significantly higher in control group than early treatment (p<0. 05)، there was no significant difference on SGR between two treatments during the whole rearing period. Relative growth rate (RGR) did have the equal progress among sampling days in control treatment، but there was significant increased pattern in early treatment (p<0. 05). Early weaning did not have significant effect on survival rate، cannibalism rate، and quality of larvae (p>0. 05). These results showed that the early weaning of Sobaity Sea bream S. hasta larvae on 18 DPH was possible without having undesirable affects on SGR، survival rate and quality loss which is more economic for farmer.