Feeding habits of the scalloped spiny lobster, Panulirus homarus (Linnaeus, 1758) (Decapoda: Palinuridae) from the South East Coast of Iran

Certain ecological aspects of the feeding habits of 260 scalloped lobsters Panulirus homarus collected during monthly dives off the southeast coast of Iran were considered. Parameters under consideration included: water temperature, salinity, turbidity, pH, dissolved oxygen and macrobenthose of the lobsters habitat. The mean number of empty stomachs varied from 25% to 62%. Statistical analysis revealed no monthly or seasonal significant difference in the frequency of non-empty stomachs (P>0.05). 1 to 6 prey items were distinguishable in each non-empty stomach. Monthly mean of point counts of prey obtained was from 8.76±4.18 to 154.95±73.62, without any significant difference by Tukeys’ HSD test. Bivalves often had the maximum amounts of Fi and Pi amongst different prey items. Pearson χ2 test did not show any significant difference between frequency of occurrence of each prey item with different length classes, sex, moulting condition and presence of eggs in females (P>0.05). Ivlev electivity index of crabs, gastropods and bivalves was close to 1 and sloped to -1 for polychaetes and echinoderms. This index revealed crabs, bivalves and gastropods were more important in the diet than sediment throughout the year. Frequencies of food occurrence suggest bivalves as the main food; crabs, gastropods, barnacles and algae as secondary food and polychaetes, fish, echinoderms and Ascidiacea as incidental food for P. homarus in the area. Spearmans’ correlation coefficients of stomach fullness against different length classes, sexes, moulting and ovigerous females were not significantly different (P>0.05). There was only a significant Pearsons' correlation between the number of point for bivalves in the stomach against body weight (P<0.05)

Biotechnics of live feed (Chironomidae) culture for using in feeding of cultured aquatics

Larvae of the chironomid midges (blood worms) are known as use full live food for cultured aquatics. There are endemic blood worms in sediments of the earthponds of Bafgh area at center of Iran. This study tended to identification of two chironomid species, Chironomus aprilinus Meigen, 1830 and Dicrotendipes sudanicus Freeman, 1959 & 1961, from Iran as a new record. Culture of blood worms was successful in glass thanks with 16h. Light, at 24-26°C temperature. Eggs were incubated after 14 days. Suitable concentration of harvesting is 1-2 egg masses (1250eggs/m2). Enrichment of earth ponds or plastic thanks including sedime is offered for culture of chironomid larvae. Collectors prepared with low cost materials are useful for collection of egg masses. May, June and July are the best time for egg collection. Large blood worms are mainly available in winter. Results of body analysis of the larvae indicated high dry matter with good quality

Tilapia culture in aquaponic system

Iran is one of ten disaster countries in terms of water crisis. Also, deficit of agricultural soil is a limiting agent for development of agronomy. Moreover, production of organic crops is very important for health nutrition. Tilapia is an important commercial fish because of its fast growth, tolerance to environmental conditions and diseases, possibility of intensive culture, low costs of production and marketable flavor. Production of aquatic and agricultural crops in an aquaponic system would ask these expectations. Aquaponic system that includes combination of hydroponics and water recycling systems was examined for modulated culture of tilapia and agricultural crops at the present study. Tilapia fries with 6.2g and 5.9g mean weight and stocking density of 40/m^3 were respectively stocked in two 2.5m^3 tanks at September 2013 for 9 months. Fish culture in the two tanks tended to 17.2kg/m^3 and 19kg/m^3 fish production with 658g and 596 mean final weigth, 98% and 100% survival and 1.4 and 1.6 food conversion rate (FCR), respectively. Plants were implanted using grow beds, floating rafts and nutrient film methods. Monthly production of mint, basil, lettuce, cucumber, tomato, pepper were 1.14, 0.5-0.8, 1.32, 2.7-4, 2.03-3.4 and 1.1 kg/m^2 crops, respectively

An investigation on feasibility of introduction of tilapia to aquaculture industry of inland brackish waters at desert areas of Iran

Use of underground inland water for fisheries aims is improved all over the world. Tilapia is the first candidate for brackish water fish culture and an economic fish based on its biological characteristics. Tilapia was entered to Iran for the first time in November 2008. Bafq area at the center of Iran was licensed by Environment Organization, because of closed underground water resources of the area. Studies showed desired growth and adaptation of Nile tilapia in brackish water earth ponds and fiber glass tanks with high survival and low FCR. Limnological factors were suitable for tilapia culture. All male samples were made using certain doses of methyl testosterone in defined period. Optimum level of protein, fat and energy were determined for the best growth and food performance of cultured tilapia. Environmental program was presented to prevent environmental problems. However, studied shoed tilapia culture had not negative effects in the area. Economical performance of tilapia culture project was desirable. Tilapia was successfully introduced to some private fish farms in June 2011. Tilapia culture may improve in center of Iran after environmental surveys

Cage culture of tilapia in some water resources (farm and agriculture ponds) of Bafq, Iran

Tilapia is the second cultured fish in the world. Up to 135 countries produces tilapia. Intensive culture systems of tilapia such as cage culture are recently developed because of limitations of water resources. In Iran, studies about tilapia were started in National Research Center of Saline Water Aquatics from November 2008 and some aspects of tilapia aquaculture and culture systems are surveyed. Investigation about cage culture of Nile tilapia, Oreochromis niloticus was performed in two culture periods of 2012 and 2014 in fresh and brackish water conditions of Iran for the first time. Stocking densities of fish in the cages were 25, 50, 75, 100, 125 and 150 fish/m^3. 100g fish stocked reached 272-331 g during 80 days in the first study. However, 50g fish stocked reached 329-450 g during 145 days in the second study. Results of cage culture of tilapia in fresh and brackish water conditions showed ranges of FCR: 1.56-3.72 and 1.08-1.87, DGR: 1.63-2.91 and 2.14-2.92 g/day, SGR: 0.63-1.12 and 1.29-1.54, production: 5.98-38 and 7.17-41.6 kg/m^3, respectively. Stocking densities 75-125 fish/ m^3 were appropriate especially in fish reared in brackish water cages

Pathogen monitoring in indoor systems of tilapia aquaculture in Bafq, Iran

In recent years, aquatic diseases have damaged aquaculture industry in different areas of the world. Although tilapias are known as resistant fish against different pathogens, but there are some reports about infectious diseases of tilapia. Tilapia aquaculture in Iran is in the beginning stage. So, planning for hygiene observations and preventing of disease prevalence must be considered. Tilapia hatchery and indoor systems of National Research Center of Saline water Aquatics were monitored for infectious disease from October 2012 to February 2014. Unusual locomotion/feeding or uncommon signs in the shape or body surface of cultured tilapias, fries and eggs or exceed mortalities were mentioned for bacterial, fungal, parasitic or viral pathogens. Infectious agents in this study were bacteria Streptococcus and Edwardsiella, the fungi Penicillium and Aspergillus and parasitic monogeneans Gyrodactylus and Dactylogyrus. No viral agent was diagnosed. Although recorded pathogens were rarely observed during the study but much attention must be paid for hygiene monitoring and instruction performance

Non-destructive measurement of chloride ions concentration in concrete – A comparative analysis of limitations and prospects

In this work, the different techniques for non-destructive in situ measurement of chloride ion concentration are presented. Non-destructive (ND) in situ measurement is crucial for reliable and continuous determination of chloride ion concentration in concrete. Over the last 20 years, several studies have been performed on ND measurements. These were mainly focused on the application of electrochemical and electromagnetic techniques. Each technique has its advantages and disadvantages. Depending on the requirement of assets managers and constructors and considering the limitations, these techniques can be well applied. The main concepts and comparative analysis, in view of possibilities and limitations, of these non-destructive techniques are presented in this paper