Evaluation of Feeding Indices of Catfish Arius Dussumieri in Oman Sea (Sistine & Baluchistan) (original) (raw)

Effect of different arsenic and phosphorus concentrations on osmolytes contents of Isatis cappadocica

Arsenic is considered as one of the most important environmental contaminant compound. Some plant species can grow in arsenic contaminated soil and they are able to reduce arsenic toxicity. Nowadays, phytoremediation as a new and friendly environmental technique employs the use of plants to remediate contaminated soil. Previous studies showed that Isatis cappadocica is an arsenic hyperaccumulator plant. Accordingly, we conducted this experiment to compare the interaction of arsenic and phosphorus on osmolytes content of I. cappadocica for better understanding the mechanisms applied by this species. Therefore, the plants were grown for 6 weeks in a medium, embedded with combinations of 50, 200, 800 & 1200 μmol l−1 arsenic and 5, 50, 200, 800 & 1600 μmol l−1 phosphorus, respectively. The osmolytes content and the arsenic concentration of harvestable parts were determined. The highest concentration of arsenic was obtained in plants treated with 1200 μmol l−1 As and 5 μmol l−1 phosphoru...

Monitoring water quality and eutrophication phenomenon of Azad Dam using Iranian Water Quality Index and Carlson's Trophic State Index

ISFJ, 2017

Water reservoirs have an important role in providing water for drinking and agriculture. It is necessary to protect these resources. This study was conducted to determine water quality of Azad Reservoir (Kordestan-Sanandaj) based on Iranian Water Quality Index (IRWQI) and Carlson's Trophic State Index (TSI). Sampling was carried out at five stations during different months in 2015-2016. Results showed that trophic status of Azad dam was mesotrophic based on chlorophyll-a parameters and eutrophic to hypertrophic based on other variables (TP, SDD and DO % at bottom layers). Mean of Carlson's Trophic State Index represented mesotrophic state (high quality) at Azad dam. Based on IRWQI, water quality of dam was classified as excellent quality. Although, mean of indices indicated the suitability of this lake for drinking and agriculture activities but due to declining water quality and increasing trophic level in some months, it is necessary to apply appropriate management strategies for maintaining water quality in the reservoir.

Effects of stocking density and feeding frequency on the growth parameters and hematocrit of the Rutilus rutilus caspicus juvenile

Nova Biologica Reperta, 2018

Feeding frequency and stocking density are important factors affecting growth and maturation of cultured fish. The aims of this investigation were to determine the effects of stocking density (10, 20, 30 and 40 fish per aquarium) and feeding frequency (2, 3 and 4 times on daily) on growth parameters and hematocrit of the Rutilus rutilus caspicus juveniles. The experiment was continued for 45 days in two replicates. The results of this study showed that growth parameters, including weight gain (WG), feed conversion ratio (FCR) and specific growth rate (SGR) were affected significantly by stocking density(P<0.05), but not significantly affected by feeding frequency (P>0.05). The highest WG and SGR were recorded with the lowest stocking density (10 fish / aquarium). The least FCR was obtained in density of 10 fish/aquarium, FCR value was significantly higher with high stocking density (P<0.05). Also, interactions between stocking density and feeding frequency were no significant on growth parameters (P>0.05). Density and feeding frequency had no significant effect of hematocrit concentration (P>0.05). On the other hand, interactions between stocking density and feeding frequency significantly affected hematocrit levels (P<0.05). The lower level of hematocrit was observed in density of 10 fish/aquarium at two times / day feeding frequency. The results of this study indicated that density is significantly affected the growth, but increasing of feeding frequency there is not effect on growth in the Rutilus rutilus caspicus.

Stock enhancement and estimation of growth rate of green tiger prawn (Penaeus semisulcatus) and banana shrimp (Fenneropenaeus merguiensis) released in the Persian Gulf

2013

Present study was conducted in the Persian Gulf (Iranian waters) from 2009 to 2012. The main objective of the research was economical evalution of the stock enhancement of banana prawn (Fenneropenaeus merguiensis) and green tiger shrimp (Penaeus semisulcatus) in the studied area. Also tagging effects on the growth and mortality of tagged shrimp were studied. In banana prawn, broodstock shrimps were hatched in June. In July 2010 and 2011some of the juvenile of this species were marked by red fluorescent liquid injection and released were made at night in the estuaries of Tiab, Kolahi and Koolgan in the Hormozgan province. 84000 juveniles of banana prawn in 2010 and about 50000 in 2011 were released in this area. In Bushehr province waters, adults shrimp were reared and when juveniles reached to optimum size, some of them were tagged by red and blue coloures and were released in the coastal waters of Bandargah and Delvar. Tagging and releasing program of green tiger prawn was performe...

بررسی محتویات روده میگوی پاسفید (Litopenaeus vannamei)در طی یک دوره پرورش در استخرهای خاکی دلوار بوشهر

2015

In this research, gut contents of white leg shrimp Litopenaeus vannamei were investigated for 113 days culture period at earthen ponds in Delvar of Bushehr, by sampling every 15 days. Results showed that artificial food had highest weight percentage in gut contents (foregut, midgut, and hindgut) following in order by detritus, zooplankton, phytoplankton, and macrobenthic. In the beginning of culture period, macro-bentic were observed in larval gut contents while other food items were throughout culture period. The maximum occurrence of detritus in gut contents was at 26 and 40 days-old larvae while highest phytoplankton was obtained at 86-days-old larvae in end of culture period. The zooplankton had approximately similar amounts throughout culture period in different parts of gut, while macro-benthic only observed at 26-old-days larvae with maximum amount at foregut and midgut. The mean highest gut fullness attained at foregut (0.95 %) and lowest at hindgut (0.20 %). The dominant color of gut content was green-brown in all parts of gut that could be due to consumption of natural pond products. This study illustrated that most consumed food items in L. vannamei was prepared by natural pond foods. In addition, detritus and plankton have most important in L. vannamei during culture period.