فصلنامه بوم شناسی آبزیان
سال ششم شماره 2 (پیاپی 602، پاییز 1395)

The Sampling one-year period from October 92 to October 93 on a monthly basis was conducted using gillnets and baited traps. 70% of gillnet catches during flood tide consisted of adults. Sub-adults and juveniles were 28 % and 4.5%, respectively. Similarly, during ebb tide consisted of 51.7%, 24.2%, and 24.1%, respectively. It suggests that gillnets are not sized selective gear. In contrast, baited traps only caught adults and sub-adults with the percentage of 90.5% and 9.5%, respectively. The CW∞ and K of males were slightly higher than females namely 21.147 and 1.38 for males and 21.023 and 0.83 for females. The mortality estimates are as follows: natural mortality (M) male = 2.48 and fishing mortality (F) male =1.2, while M female =1.78 and F female = 0.75. The results show that S. serrata population is still less than underexploited.

Along with the development of urbanization over the past century, water consumption in urban areas rose sharply. Produce large amounts of waste in cities around the world on the one hand, and restricted access to freshwater resources, on the other, increase the requirement to regard for recycling of domestic wastewater. Especially in the Middle East region, that has an arid and semiarid climate. A major problem in urban wastewater purification treatment systems using conventional is chemical oxygen demand and high organic carbon content in the effluent, which creates environmental restrictions for the reuse of treated wastewater. So today, the use of algae in the biological treatment of wastewater is considered as a global strategy. In the present study, for the first time, we evaluated the performance of a BIODROF system that in this system the algal biofilm is added to its bacterial part for decrease COD and TOC content in domestic wastewater. In this regard, a biological treatment system was designed, that consists of four sectors including oil separator, Sediment Retention part, suspended solids trap and BIODROF system as part of the fourth. After inoculation system with algae-bacterial biofilm, municipal wastewater for biological treatment process was added to the system. The results of the testing period of 9 days showed a higher removal efficiency of COD and TOC compared to similar studies at the same time. The uptake efficiency for COD and TOC was at least up to 95% and 92% of their initial concentration respectively. Finally, we can say that the symbiosis of algae and bacteria with favorable conditions for gas exchange in BIODROF system, could be a good reason for the better performance of our system compared to similar systems.

This study aimed to determine the effects of dietary prebiotic Immunogen on the compensatory growth of koi carp (Cyprinus carpio) fingerlings (n= 300; 3.60 ± 0.12 g), following one-week starvation. The experiment was conducted within 60 days with three treatments. In treatment C, fish were fed with non-prebiotic diet and with no starvation period, while in treatment G1, fingerlings starved for one week then fed with 2.0 g of Immunogen per kg diet, and in G2, fingerlings received no prebiotic following one-week starvation. The results showed that the highest final weight and specific growth rate (SGR) were observed in the control followed by G1 (P<0.05). The lowest feed conversion ratio (FCR) was recorded in treatment C. Numbers of red blood cells were similar in all treatments (P>0.05). Hemoglobin and hematocrit were maximum in C. G1 contained the highest number of white blood cells (WBC) (13690±550). In WBC differential counts, significant differences were observed only in neutrophils and lymphocytes (P<0.05). The minimum number of neutrophils and the maximum number of lymphocytes were observed in G1. Based on the results, although the addition of 2.0 g of prebiotic Immunogen in the diet of koi carp fingerlings could not improve their growth performance, it could give rise the better results compared with G2 which fed with no prebiotic after starvation. Furthermore, the fingerlings in G1 showed the best results in terms of immunity.

Pollution of aquatic environments by toxic trace metals has been taking place because of discharge of untreated effluents from many industrial processes. Conventional methods used for removing dissolved heavy metal ions from wastewaters have significant disadvantages including incomplete metal removal, requirements for expensive equipment, high energy requirements and generation of toxic sludge or other waste products that require disposal. In the present study, G. corticata algae waste biomass was investigated from aqueous solutions the removal of cadmium and copper, and the effects of different parameters such as pH, the initial concentration of pollutants, adsorbent dosage and contact time were studied. The results show that the Maximum uptake capacity for cadmium metal was in pH 6, metal concentration 10 mg/L, biomass 0.4 g/L and contact time 80 min and copper metal were in pH 5, metal concentration 10 mg/L, biomass 0.4 g/L and contact time 40 min. The study equilibrium results, for both metal, followed the isotherm data fitted to Langmuir with Correlation Coefficient (R2) 0.98 for cadmium and 0.97 for copper. The maximum capacities (qmax) were for cadmium 197.4 mg/g and copper 194.4mg/g. Therefore, G. corticata algae waste biomass suggested as suitable biosorbent to remove heavy metals from cadmium and copper-polluted aquatic ecosystem.

The growth performance and survival rate of spats of winged pearl oyster (Pteria penguin) fed with two microalgae, Isochrysis aff. galbana and Chaetoceros calcitrans, as well as the combination of both species over a period of 60 days, was evaluated. The microalgal density was considered 50000 cell.ml-1 in all treatments. The spats divided into 5 different groups; (1) spats fed exclusively with I. aff. galbana; (2) those fed with the ratio of 70:30 I. aff. galbana and C. calcitrans; (3) spats fed with 50:50 I. aff. galbana and C. calcitrans; (4) those fed with 30:70 I. aff. galbana and C. calcitrans; and (5) individuals fed exclusively with C. calcitrans. Results demonstrated that total length was significantly higher in treatments 2, 3, and 4 in compare to 1 and 5. However, heel length was same for all treatments. The thickness of treatment 2 was significantly higher than both treatments 1 and 5. This value was not different between treatments 3 and 4 with 1, but significantly higher than that of treatment 5. Survival rate was same for all treatments. According to the obtained results, feeding with a combination of both microalgae is recommended for the culture of P. penguin spat.

This study aimed to determine the fat requirement and effect of dietary fat levels on growth and body composition indices of Bester (Huso huso ♀ × Acipenser ruthenus ♂) juveniles( 200.3 ± 2 g) in winter feeding. Fish were fed by 5 isonitrogenous diets (40% crude protein) with different fat levels including 10, 13, 16, 19 and 22%, 3 times daily according to the satiation for 50 days. The results showed that some growth indices such as final weight, body weight increase, specific growth rate, feed conversion ratio and protein efficiency ratio were significantly affected by different levels of dietary fat. Proximate analysis indicated that the fat, moisture and protein contents of the whole body were affected by the diets, body composition of fish fed the 22% fat diet showed significantly higher fat and lower moisture contents, as well as body composition of fish, fed 10% fat in the diet showed significantly higher moisture lower protein and lower fat. From the results, the present study suggests that more suitable dietary fat levels in winter feeding for the Bester growth might be around 13%.

Feeding habits of the blue swimming crab, Portunus segnis were studied in the coastal waters of Chabahar (Oman Sea) during the period from January 2015 to June 2015. The stomach contents of 623 crabs (included 138 males and 125 females) were analyzed. Their contents appeared to consist of mainly large quantities fish (48.2 %), crustaceans (19 %) and molluscs (15.7 %), also small quantities of seagrass (3.3 %), mixed matter (8.8 %), unidentifiable matter (5 %) and debris. The C.V. index was 44.8 %, also the crabs in the warm season most voracious (CV=38.9 %) than in cold season (CV=51.1 %). The crabs without barnacle comparatively voracious with barnacle-carrying crabs (p<0.05). There was no difference observed in the quantity of the food consumed in both sexes and also significant differences observed in the preference for food items in the different size groups. Based on the major food items were observed in different size groups, the crustaceans, fish, and molluscs were the most dominant in juvenile crabs and the fish items were the most dominant (with 62 %) in adult and larger size groups crabs.

In the present study, we investigated biological characteristics and population dynamics of long-spined tripodfish, Pseudotriacanthus strigilifer</em>, in coastal waters of Hormozgan province. A total of 391 fish samples were collected from September 2014 until September 2015 by the set net of Moshta. Length frequency data were analyzed using FiSAT software and ELEFAN 1 method. The longest and the shortest fish sample was 28.5 and 3.1 cm, respectively, and the minimum and the maximum weights of the fish were 0.8 and 297.07 g, respectively. The value of b</em> was estimated 3.39 with a positive allometric growth pattern. The growth functionality index of phi-monro (</em>ϕ</em>)</em> was 2.98. Von Bertalanffy growth factors </em>(VBGF) were calculated (L∞</sub>=29.8 cm, k=1.1 year-1</sup>, t0</sub>=-0.14). W∞ </sub>was obtained 302.09 g. The total, natural and fishery mortality rates were 2.35, 1.86 and 0.49 year-1</sup>. Catch probability of each length range in long-spined tripodfish was obtained L25</sub>=10, L50</sub>=12, and L75</sub>=13 cm.

To assess the acute toxicity of colloidal silver nanoparticles (AgNPs) in Nannochloropsis</em> oculata</em>, microalgal cells were exposed to different concentrations of AgNPs for 72 hours and according to OECD 201. Algal cell count was done every 24 hours and average specific growth rate, as well as percent inhibition of the average specific growth rate, were calculated for each concentration. Also, the amount of inhibitory concentrations (IC) and median inhibitory concentration (IC50</sub>) of this nanomaterial were calculated according to the percent inhibition of the average specific growth rates and by using the Probit Analysis program. The results showed that even at the lowest concentration (0.005 mg/L), silver nanoparticles reduced the growth of Nannochloropsis</em> microalgae. Accordingly, No Observed Effect Concentration (NOEC), Lowest Observed Effect Concentration (LOEC), and IC50 of this nanomaterial for tested microalgae were 0.001, 0.005, and 0.036 ± 0.009 mg/L. On this basis, and considering the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), tested AgNPs are classified as “category acute 1” or “very highly toxic” for N. oculata</em>, so any accidental or intentional release of AgNPs containing wastewaters to aquatic ecosystems may cause irreparable effects on the aquatic environment.

Marine algae are shown to contain a wide range of bioactive compounds, which have commercial application in pharmaceutical, medical, cosmetic, nutraceutical, food and agricultural industries. The biological activity of the natural bio-active compounds in algae has wide effects on bacteria, tumors and antioxidant activities. The purpose of this study was to determine antibacterial activity of the marine algae. Different algae (green, brown, red) were subjected to the three solvents (n-hexan, ethyl acetate, methanol). Antibacterial activity of the extracts was performed using 7 bacteria by disc diffusion method. According to the results of the study, highest the According to the results, B. subtilis with the greatest sensitivity to green algae and U. intestinalis</em> and U. linza</em> and P. aeruginosa</em> bacteria most resistant to most algae species studied shown. The findings of the study showed that green algae, brown algae and red to have strong antibacterial effects.

The present study aimed to survey heavy and toxic metal pollution (lead and cadmium) in the southern Caspian Sea basin through Liza aurata</em> using geographic information system (GIS).  Samples of the gill tissue of adult Liza aurata</em> were taken in 10 stations over the southern coast of the Caspian Sea in spring and fall. Interpolation method, Kennedy density function, Moran test, and Gi* index in the GIS were used to determine the spatial distribution, density, zoning and distribution pattern of the metals. The uptake of lead and cadmium was 1.88 and 1.23 µg/g in spring, and 1.42 and 0.79 µg/g in fall, respectively. Analysis of GIS maps showed that concentration and centralization of both metals reduced from East to West. According to Moran test and Gi* index, the distribution of the metals had a strong and hot cluster pattern that reveals the accumulation and closeness of high-density polluted areas. Finally, it can be stated that the pollution of the eastern part of the Caspian Sea (Bandar Turkman and Khajeh-nafs) is higher than permissible international standard limits.

The blue green algae as photosynthetic organisms have a main effect on life and productivity of the aquatic ecosystems. Intensive and longtime studies on identification, distribution, and diversity of Cyanophyta have to be a crucial task in the Caspian Sea. Four transects were determined parallel to the Sabzehrud River, the Lavij River, the Noor River, and the Faculty of Marine Sciences of Tarbiat Modares University from 2014 to 2015. Samples were seasonally collected from three stations in each transect by a plankton net with a mesh size of 55 and the Ruthner's bathometer. Standard hydrobiological and phycology approaches were used for identification and counting abundance of Cyanophyta. The most number of Cyanophyta was observed 1.06 × 106 cells per liter at the station of A1 during summer. Genera such as Chroococcus, Gloeocapsa, Merismopedia, Microcystis belonged to unicellular taxa and Anabaena, Anabaenopsis, Nostoc, Oscillatoria, Phormidium were identified as multicellular genera. At the most stations, Anabaenopsis nadsonii was found as the most encountered species. Overall, Cyanophyta abundance was significantly different among stations in all investigated seasons. The blue green species also did not have same frequency distribution inside of the each transect (Test Chi-Square, P</em> <0.05).

In this study, the effects of different concentrations of Sargassum angustifolium</em> (Agardh, 182 (</span> extract on the hematological parameters in Common carp were investigated within 14 days. A total of 240 common carp were divided randomly to four treatments (control group without algae extract, 1% algae extract, 10% algae extract and 50% algae extract). Blood samples were taken on days 1, 3, 7 and 14.</span> Hematological parameters were measured: white blood cell count (WBC), red blood count (RBC), haematocrit, Hb, RBC index (MCHC, MCH, MCV) and respiratory burst (NBT). At the end of the experiment, compare of treatments with control group showed significant difference in hematocrit, mean corpuscular hemoglobin concentration (MCHC) (%), total count of red blood cells, respiratory burst (NBT), heterophil, lymphocyte, monocyte (p</em>>0.05). But significant difference was observed between the control group and treatments in the amount of hemoglobin, total count of white blood cells, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) (p</em><0.05). The results of this study showed that the extract of Sargassum angustifolium </em>(Agardh, 1820) can be effective on some blood factors of common carp at the concentrations of used.

Different groups of animals show phenotypic characters, which have been resulted by the reductive phenomena. The examples are the absence of pigmentation; dwindle of eyes in some cave-living animals, and also the absence of scale in some fishes. These characters are often leaded to evolution of new species with special adaptation that is so called "Regressive evolution". The reductive phenomena occur as a result of a long time adaptation of populations to the environments with extreme ecological conditions such as high salinity, high solphure and low oxygen concentration. Many fish species such as the only Iranian scaleless tooth-carp (Aphanius furcatus</em>) have been evolved by this event. The principle mechanisms of this event have not been understood well, but it is suggested that some specific genes such as Ectodysplasin probably play role in the reductive event because Ectodysplasin is responsible to produce the ectodermal structures such as teeth and scale. Therefore, mutation in this gene pathway causes reduction in development and forming of the ectodermal structures. As results, the reductive events in most of the animals caused speciation, while the result of this event in human seems to be different than other animals.

One hundred and five fish with an average weight of 2.5 g from the aquaculture center in the port of Turkmen, Golestan province, were cached, sub-lethal test was for 1 week with 5 treated of diazinon as 0, 25, 50, 75 and 90% of LC50</sub> (0, 0.42, 0.85, 1.28 and 1.17 ppm, respectively). The results showed that with progress of poison, gill tissue lesions will be increased such as hyperemia and hemorrhage, fractures and secondary lamellar connection, one-way and two-way lamellar cast gill and shorten the secondary lamellar, swollen, multicellular be harder to lamella.