نشریه علوم آبزی پروری پیشرفته
سال دوم شماره 1 (بهار 1397)

This study was carried out to evaluate the effect of floating and sinking pellets on growth performance of common carp (Cyprinus carpio). Triplicate groups of 624 carp (average  initial weight 175 g) were stocked in 6 round concrete pond with a density 1/8 kg/m3 and fed to apparent satiation, 4 times a day with interval of 4 h for 75 days. The growth rate of fish was estimated by feeding the extruded and pellet feeds 122.63 and 77.43g respectively. Fish were fed from two type of feed in this culture system had a high survival rate (97-99.5%). Thus, high survival rate of carp in concrete ponds indicate its easy adaptation to new cultural conditions. The results showed that growth and nutrition parametrs included in:weight gain (WG%), specific growth rate (SGR), protein efficiency ratio (PER) increased and food conversion ratio (FCR) decreased significantly when they were fed on floating pellets compared with the fish fed on sinking pellets (p<0/05). Thus, the results showed that carp, despite the oral form and feeding habits of the bed, can easily feed on the floating pellets and have better growth performance.

In this study 180 beluga(Huso huso) weighted 120 ± 10gr with stocking density of 12 fish/tank ,after adaptation with synthetic diet , fed different levels of AFB1(0,25,50,75 & 100ppb/kg of diets) under controlled conditions(T=18±2ºC,DO=7.3ppm). The fish were fed 3% of body weight four times a day for 120 days.Record of physical and chemichal water caracters include : DO , temprature , pH , did weekly . Residue of AFB1 in muscls in different exprements determined by HPLC method . The amount of AFB1 in mscle was between 0.36 -2.90 ppb .Based on international standards these amount is not harmfull for human consumption.

Prosperous of fish aquaculture relied on the mass production of high quality of larvae and juveniles, which is dependent on successful initial feeding, normal development, and growth of larvae. Also, the growth and survival of newly hatched larvae are primarily attained by the impressive digestion, absorption, and utilization of nutrients following the feeding. However, numerous fish species developed for aquaculture show high mortality during early development. For mass fish production, therefore, it is important to decrease mortality. Thyroid hormones have been well known to have an important role in early development of fish and also known to be present in the eggs and newly hatched larvae and can affect fish survival and growth. There are various methods for using thyroid hormones, which consist of injection, implantation, oral administration and immersion. Regarding that, the role of thyroid hormones in development, swim bladder inflation and immunity enhances it can be used widely in aquaculture industry. In this study, the role and applications of thyroid hormones in fish physiology will be discussed, as an important strategy for improvement and development of aquaculture and it was found that the use of thyroid hormones in optimal doses could improve growth and reproductive performance in aquaculture.

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.

The presence of a large diversity of massive macro-algae on the coasts and seas of the southern part of Iran (the Persian Gulf and Oman Sea) include of 167 red algae, 79 green algae, and 80 species of brown algae showed a promise prospective of the biofuel extraction potential from the Persian Gulf marine macro-algae and the production of a powerful phase of clean energy beyond the fundamental national research that hat its production methods have been interpreted in this paper. These marine algae, especially in the bloom seasons have a very large weighty biomass, but except for a few local uses, are released useless on the beaches. Biomass of these algae contains three important components of proteins, carbohydrates, and lipids. The presence of more than 40% of fatty acids in some of these algae can be extracted as oil feedstocks, as well as by biochemical/thermochemical/fermentative microbiological processes that can extract and utilize the total carbon content of algae for the production of safe fuel in the industrial scale. These processes can easily convert these algae compounds into a variety of bio-fuels such as bio-diesel, bio-gas, bio-hydrogen, bio-ethanol, bio-butanol, methane, and charcoal.

Salmo trutta is one of the native fish that is endangered due to the sensitivity to environmental pollutants (entry of various pollutants including domestic, industrial, detergents, petroleum, etc.) of its generation. This study was carried out on 140 fresh salmon trout (Salmo trutta) fish from the mountainous region of Lar Lake in 2008 and 2009. The study their demographic structure. Based on Kruskal-Wallis non-parametric test, the statistical difference in gonadal weight (1.26 ± 0.016), relative weight of gonad (1.21 ± 0.020), Fulton index (1.50 ± 0.017) and Clark index (0.99 ± 0.015) was observed (p <0.05). T-test did not show any statistical difference in indexes such as body weight (153.44 ± 9.60 gr) and fork length (21.72 ± 1.85 cm) in both males and females at different ages (p> 0.05).

In the studies of the comprehensive fishery project of the Hassanloo lake, planktonic studies were considered as basic studies to increase the production of fish in this lake.These studies were carried out  during three phases of  sampling  from 2001 to 2005 to this lake in the West Azerbaijan. Plankton sampels were collected with (P.V.C) tube (lenth, 2m), in  Phytoplankton 1 liter water samples (without filtering )and in Zooplankton 30 liter water sample were filtered with a (30 µm) Zooplankton net , Finally  sampels were fixed with % 4 formaldehyde. in laboratory  sampels after preparetion  were identified and counted under  a invert  Microscope. In phytoplankton research, there were 5 phyla and 52 genera and in zooplankton 3 Phyla and 34 genera were identified in this lake.The production indicate seasonally which the peak of phytoplankton density occured in Summer and the Phylum of Bacillariophyta were abundant and among Phytoplankton genera Synedra,  Diatoma, Nitzschia and Navicula showed dominate in water-body. In general the yearly average of  Bacillariophyta  numbers calculated 2494127 / lit. It had  %38 population  during  year. In Zooplankton study results showed that  Rotatoria had  maximum density in Spring  and among  Zooplankton genera Synchaeta , Keratella , Lepadella and Brachionus showed dominate  in  water-body. In general the yearly average of Rotatoria numbers calculated 1298 / lit and it had %66.3 Zooplankton population during year. Comparison of planktonic observations and physical and chemical data of water, showed that  Hassanloo  lake  have  talents and suitable planktonic species for feeding and rearing their fish. Thus, Natural reserves of this source can be used to increase the value of fishery fish.

Fish ball is a product, comprising a  combination of pure fish meat and authorized additives,  is consumed both raw and cooked. Within the present study ,the major objective of opting for  canned meat production was to determine the most suitable starch content in order to improve tissue quality, sustainability, and sensory quality of fish. In order to optimize the fish soup formulation, two types of wheat and wheat starch were in a separate  and mixed  way in an equal proportion  at levels of 5, 10 and 15% with 80% cornflour meat in 6 treatments. Authorized  additives and natural flavors (onion, garlic, salt, eggs, spices) were used for all groups of intervention  and control. The results revealed that the use of 5% starch in the production of fish soup was not acceptable in terms of color, odor, and texture. The intervention or treatment group  participants with 15% starch samples, due to the high starch content , were only desirable largely because of  the presence of whiteness. As the starches increased, the color of the coat was brighter and more acceptable; however, in terms of texture, being  an important indicator, the intervention or better called treatment failed to keep  its  form maintaining  capabilities. When  two types of starches –with a proportion of  10% and separately – were used in cooking fish balls , there was no significant difference in color, odor, taste and texture indices. The characteristics of evaluation (color, odor, taste and texture) in 10% -combination (5% potato, 5% wheat) treatments were higher than those of  10%- separation of wheat and potato starch. Based on the investigation and the obtained results from the tests conducted , it is grasped that the canned fish ,having been kept without any microbial flavours for two years, was compatible with the established standards. Thus canned fish ball is capable of being kept for two years in 25 c°