NEW TECHNOLOGIES IN AQUACULTURE DEVELOPMENT (JOURNAL OF FISHERIES)
Year:2015 | Volume:8 | Issue:4 |Papers Count:13

Effects of different thawing method i. e. in a refrigerator, in water, at air ambient temperature and in a microwave oven on chemical (TBA, FFA, FA), biochemical (pH, Th. L) and sensory indices were carried out on frozen whole Caspian sea Kutum (Rutilus frisii kutum) carcasses. The values of PUFA, PUFA/SFA. EPA+DHA/C16: 0 and pH of thawed samples decreased significantly while TBA, FFA, SFA and MUFA increased compared to the fresh fish (unfrozen) as control samples. Also, sensory evaluation all of thawed samples showed a significant (P<0. 05) quality loss compared to the fresh fish as control samples. The lowest chemical, biochemical values and gill odour score were determined in water thawed samples. Therefore, based on this study thawing in water is most suitable for frozen whole Caspian Sea Kutum and it plays an important role in maintaining the quality of whole Caspian Sea Kutum.

Fish cage culture due to global demand in recent years has increased dramatically and now as the fastest way in response to global needs, especially in developing countries. Forecasts show that in developing countries, fish consumption up to 57% from 1997 (62. 7 million tons) to 2020 (98. 6 million) increase. Studies in Iran, did not receive continuous on the cage culture. The study area was the southern part of Caspian Sea. The study objectives include determining areas and introduced species of fish farm with an emphasis on depth and some physical and chemical parameters (temperature, salinity and dissolved oxygen) in various layers of the water and were in different seasons. The results showed that in the south central area of the Caspian Sea in Mazandaran province, as has been the best part. Also, the use of floating cages less than 20 meters in depth, it is necessary that the temperature of the fish used 26 ° C is tolerated in the summer. Otherwise it must be immersed in the cage and the establishment of more than 20 m depth is used.

Immunogen is a commercial prebiotic that, it’ s the product of a natural combination contains several substances such as beta-glucan and mannan-oligosaccharides that are used as a food supplement in aquaculture. This study was designed to examine some immunological parameters of (Barbus grypus). 360 pieces of fingerling with an average weight 35± 2 gr were randomly divided into for treatments (three replicates per treatment). Treatments respectively were diet with feed containing a immunogen with surface zero, 0/5, 1 and 1/5 for during 12 week and on days 30, 60 and 90 to measure serum laysozyme, total serum immunoglobulin levels and the bactericidal serum activity. The results showed that prebiotic immunogen causing laysozyme activity levels of treated fish showed that fish fed with 1 and 1/5 percent immunogen are higher than the control group, but the increase was not statistically significant (P>0. 05). Bactericidal serum activity in the treatment of 1/5 percent immunogen in some stage of sampling was significantly increased compared with control (P<0. 05). But the rate of total serum immunoglobulin did not show any significant difference (P>0. 05). The results showed that different levels of immunogen prebiotic were effective on Improve the immunity response of fish (increasing activity laysozume and bacteria serum activity) So, prebiotics can be used as suitable food supplements for the dietary Barbus grypus.

In this survey were studied identification, distribution, density and biomass of zooplankton (holoplankton) in 4 seasons and different depths in 2009. Samples were taken by plankton net (100 micron mesh) from 8 transects (from Astara to Turkmen port) and various depth (5 m, 10 m, 20 m, 50 m and 100 m) and were fixed with formalin 4%. In this survey, we identified 4 groups that including Copepoda, Rotatoria, Protozoa and Cladocera from holoplankton. The most abundance and biomass of zooplankton were 8743 ind/m3 and 38. 71mg/m3 in spring (in 5m depth), 7924 ind/m3 and 71. 23 mg/m3 in summer (in 10 m depth), 7773ind/m3 and 41. 75 mg/m3 in autumn (in 5m depth) and 20025 ind/m3 and 323. 80 mg/m3 in winter (in 5m depth). The abundance decreased from surface to deep depths. Non-parametric statistical analysis based on Kruskal-Wallis showed that there were significant differences between zooplankton abundance in different stations and depths in different seasons (P<0. 05).

In this study, fish burgers of common carp (Cyprinus carpio) were investigated for quality changes during frozen storage (-18 ° C). Chemical composition (protein, fat and moisture), chemical indices of spoilage (peroxide value, thiobarbituric acid, volatile nitrogen and pH) and organoleptic properties were analyzed in zero-phase (one day after freezing) and end of every month of frozen storage (phases 1, 2, 3, 4, 5 and 6). Panelists scored for color, odor, flavor, genera acceptability and texture, using a five-point hedonic scale. During frozen storage, total lipid content of fish burgers significantly decreased at the end of frozen storage (P≤ 0. 05). Peroxide values (PV) of fish burgers significantly increased at the end of fourth month (P≤ 0. 05) then decreased until the end of the storage period (P≤ 0. 05) and reached to 12. 82 (meq O2/kg). During frozen storage TVB-N and TBA values increased significantly and reached to maximum level of them 28. 33mg N/100g and 0. 42 mg malonalde hyde/kg, at the end of sixth month, respectively. All of the sensory parameters had decreased significantly at the end of storage period (P≤ 0. 05). The most precise indices for shelf-life determination of common carp fish burger is sensory evaluation and TVB-N (about 25 mg in 100 g fillet). According of sensory evaluation and TVB-N value, shelf life of the common carp fish burger during frozen storage was set to be five months at-18 ° C.

In order to survey on the incidence of Lernea sp. on the big head carp (Aristhichthys nobilis), in rearing ponds of Shushtar, lies in Khuzestan province during warm season, 275 fish were captured from four ponds by fishing net and transferred to laboratory of veterinary medicine, Kazerun Branch of Islamic Azad university by Containers of formaldehyde 10%. After identifying the Lernea sp. by identification keys, biometric operations were performed on infected fish. The results showed that from 275 fish, 78 fish were infected by lernea sp. which formed 36. 28% of the captured fish. Results showed that there was no significant relationship between total length and body weight with number of lesions on the body and also between lesions and coefficient factor (P>0. 05).

This study was conducted to determine effective factors on shell selection behavior of hermit crab Clibanarius signatus in 6 selected stations which were located in the intertidal zones of Hormuz Island. Seasonal sampling was conducted during the summer 2010 to spring 2011. Samples of each station were fixed in 70% ethanol separately and transported to the laboratory. Shells occupied by each of the samples were identified at the species level. 5 biometric factors in hermit crab (cephalothorax length, shield length, cheliped length, cheliped height and hermit weight) and 5 biometric factors (shell length, shell width, aperture length, aperture width and shell weight) in occupied shells in each of the seasons and the correlation between the measurements was assessed by the Pearsonʼ s test. The hermit crabs shell utilization in the spring, summer, autumn and winter, were respectively 20, 17, 25 and 22 species. The number of occupied shells in different seasons showed that shell selection in this hermit crab species is not based on species-specific gastropods. The highest correlation was found between shell width and cephalothorax length in the hermit crab. Results showed a significant correlation between all factors measured that confirmed the shell selection behavior in C. signatus is fully optimized and appropriate shells are available (P<0. 01).

To determine and measurement of organochlorine pesticides (OCPs) were done from sediments samples in southern part of Caspian Sea (coastal part of Mazandaran province) with emphasis on fish feeding from benthic animals during spring and summer seasons (2008) in 10 m depth at Tonekabon, Noushahr, Babolsar and Amirabad stations. The results of OCPs compounds shown that the maximum concentration of OCPs compounds such as Lindane, DDT, DDE, Dieldrin, Heptachlor, -BHC, -Endosulfan and Endrin were 4. 43, 0. 76, 0. 74, 0. 74, 0. 22, 0. 11, 0. 1, 0. 04 mg/kg of d. w., respectively. The minimum concentration of OCPs compounds that detected such as DDT, DDE, Dieldrin, -BHC, Lindane, -Endosulfan and Heptachlor were 0. 06, 0. 03, 0. 05, 0. 04, 0. 05, 0. 03 and 0. 06 mg/kg of d. w., respectively. The statistical results on stations group shown that there are not any correlations coefficient between mean ranking with different OCPs compounds and different stations (P>0. 05). But, in evaluation with seasons group shown that the two chemicals such as DDT and Dieldrin have strong positive correlation coefficient and DDE compound has very strong positive correlation coefficient. The maximum percentage of chemicals compounds and OCPs concentration were detected in agricultural season.

In this study, the effect of Sabrzard extract (Aleo vera) on growth of Shyrbot (Barbus grypus) was investigated. For these purpose three concentrations of Aloe vera extract, 0. 1, 0. 2 and 0. 5% (in triplicates) were mixed with the feed and the fish were fed with this diet for 60 days. Control group was fed with the control diet without Aloe vera extract. Growth parameters include weight gain, increase of length, condition factor, feed consumption, feed conversion, specific growth rate, protein efficiency ratio and food efficiency were measured. Results indicated that feeding Shyrbot with Aloe vera extract 0. 2% lead to significant increase in the quality index, specific growth rate and weight gain (P<0. 05). Also feeding with extract 0. 5% lead to increase of quality index (P<0. 05). Effect of oral administration of different doses of Aloe vera on feed conversion, protein efficiency ratio, feed efficiency comparison between treatments and control group were different significantly (P<0. 05). Altogether we can say that the better doses of Aloe vera in diet for growth excitement are 0. 2 and 0. 5%.

This study investigated the relationship between some physic-chemical characteristics of the water ponds with different density of warm water culture fishes. We selected 10 fish ponds with different densities of warm water culture fishes, including densities of 2200, 2400, 2600, 2920 and 2950 (part of a hectare). Water characteristics such as Nitrite, pH, Ammonium, Phosphorus, Dissolved Oxygen, Salinity, Ammonia Nitrate, Transparency and Alkalinity were measured. These parameters were estimated by standard methods. One way ANOVA of data showed significant difference between the different densities in most water quality parameters, there was no significant difference between the mean phosphorus, salinity, hardness, transparency and ammonium concentrations. Based on these results, the density had effect on water parameters.

Vacuum deep-fat frying is a new technology that can be used to improve quality attributes of fried food because of the low temperatures employed and minimal exposure to oxygen, In this research atmospheric and vacuum frying of Golden Mullet (Liza auratus) Fillet were compared, Tow pressure levels (70, 1 and 101, 325 kPa), with three thermal driving forces (Δ T=50, 70 and 90 ° C, constant difference between the oil temperature and the boiling point of water at the working pressure) were used for frying, The effect of frying pressure conditions and frying temperature on drying process and oil absorption of Golden Mullet (Liza auratus) Fillet was investigated, Moisture loss and oil absorption of fried Golden Mullet fillet were significantly affected by frying pressure and frying temperature, The results showed that the moisture content decreased with increasing frying pressure and frying temperature and fat content increases, Interestingly, a strong relationship between water loss and oil content was observed in both technologies, Vacuum frying was shown to be a promising technique that can be used to reduce oil content in fried Golden Mullet (Liza auratus) fillet,

Progesterone, stroeid hormone, have very important role in controlling of reproduction and sexual maturity of fish. This survey aimed to investigate changes in progesterone hormon in female of Labeo rohita during years of 2011 to 2012 in different seasons climatic from Khuzestan province. In order to determine the amount of sex hormones in plasma samples, 40 fish-breeding of Labeo rohita (1200± 80 g) was carried out they were stocked in three 1700 m2 each earthen ponds with the sexual ratio 1: 1. In each season blood was collected from 10 Labeo rohita (from caudal pedacle) then hormone was assessing with radioimmunoassay method (RIA). Mean of weight of fishes in spring, summer, autumn and winter were 1207. 5± 69. 58, 2464± 387. 01, 2718± 378. 42 and 2511. 25± 102. 5 g. The mean concentration of progesterone in female fishes in spring, summer, autumn and winter were 0. 027± 0. 04, 0. 16± 0. 02, 0. 86± 0. 01 and 0. 56± 0. 05 ng ml-1 respectively (P<0. 001). The highest and lowest of progesterone were in autumn and summer of Labeo rohita (P<0. 001).