فصلنامه بوم شناسی آبزیان
سال هشتم شماره 1 (پیاپی 801، تابستان 1397)

In this study, the leaf extract activity of two species of mangrove plants, Avicennia marina (Avicenniaceae family) and Rhizophora mucronata (Rhizophoraceae) was compared in biosynthesis of silver nanoparticles (AgNPs). The AgNPs were investigated using spectrophotometry, transmission electron microscopy (TEM), scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). Absorption spectrum in 420 nm confirmed the synthesis of AgNPs. The evaluation of the recorded TEM images from silver nanoparticles showed that the size of nanoparticles synthesized by A. marina was in the range of 0 to 75 nm and the size of nanoparticles synthesized by R. mucronata was in the range of 0 to 80 nm. The results of FE-SEM image analysis showed nanoparticles with a size between 15 to 43 and 10 to 19 nm for A. marina and R.mucronata, respectively. The results of EDS indicated the presence of 51.6% and 73.5% silver in nanoparticles synthesized by A. marina and R. mucronata, respectively. Results suggest that the leaf extracts of both mangrove species are able to reduce the Ag+ into Ag0 in the solution of AgNO3 at room temperature and synthesize silver nanoparticles of very suitable nanometric dimensions.

This study evaluated the acute toxicity of herbicide paraquat and the insecticide permethrin and their impacts on growth and reproduction of freshwater rotifers Brachionus calyciflorus according to the guidelines OECD. The acute toxicity (LC50 24h) of paraquat and permethrin on freshwater rotifers B. calyciflorus were 0.541 and 8.997 mg l-1, respectively. The level of exposure responses of rotifers to four different concentrations of the pesticide paraquat (0.027, 0.054, 0.1 and 0.27 mg l-1) and permethrin (0.449, 0.899, 1.799 and 4.498 mg l-1) with three replicates per concentration was evaluated for ten days. The results showed that the specific growth rate and populations of rotifer decreased by increasing the concentration of toxins in the culture medium (p<0.05). The highest population density in response to permethrin was 56.6±1.5 in samples treated with concentration of 0.449 mg l-1. The highest population density in response to paraquat was33.3±2 in samples exposed to concentration of0.027 mg l-1). Also, the specific growth rate was 0.23 in control treatment and zero in rotifers exposed to concentrations of 1.799 and 4.498 mg l-1 permethrin. Moreover, the specific growth rate was 0.14 in control treatment and zero in treatments exposed to concentrations of 0.1 and 0.27 mg l-1 paraquat. The results of this study showed that the toxins paraquat and permethrin are in the category of very toxic and moderate toxicity for rotifer B. calyciflorus, respectively.

Tiger– toothed croaker (Otolithes ruber) is considered as a commercially important target species for fishermen in south of Iran, due to its high economic value and marketability. This investigation was carried out using bottom monofilament gillnet with mesh size (stretch mesh) of 8.5 cm and net height of 6 m, made of nylon twine (Polyamide) and a hanging ratio of 50% in order to determine species composition and Catch Per Unit Effort (CPUE) in Jask coastal waters during 2011- 2012 fishing season. A total of 7651 individuals belonging to 39 species and 36 families at 178 times shooting were captured and measured. O. ruber was the dominant species in this area (26.81 %.). The length range of this species was between 17.3– 58 cm and the maximum frequency was in 35-38 cm length class and the length average was 36.93 ± 5.02 cm. The current fishing pattern showed that 37.19% of catch is below length at first maturity. The CPUE of O. ruber was the highest in March. (2463.33 g/ panel days) and the lowest in November (11224 g/ panel days).

Di(2-ethylhexyl)phthalate (DEHP) is a plasticizer in a variety of consumer products. Given the adverse toxicity effects of DEHP on living organisms, its high consumption and dispersal has been caused a serious concern. . Nowedays, the Fish Embryo Test (FET) method is widely used among the conventional methods of toxicology .The aim of the this study was to determine the acute toxicity of Di(2-ethylhexyl)phthalate on zebrafish (Danio rerio) embryo using FET method to assess both lethal and sublethal endpoints and anomalies effects over 5 days . Zebrafish embryos (3 hours post-fertilization) were exposed to different concentrations of DEHP (0.05, 5, 20, 35, 50 and 100 µg/l) for 120 h, then, lethal and sub-letahl endpoints of embryos evaluated and data were analized using Probit software. The LC50, NOEC and LOEC values obtained for DEHP were 46.14, 12.08 and 22.06 µg/l, respectively. Also, There were abnormalities including coagulation of the embryo, lack of somite formation, non-detachment of the tail bud from the yolk sac, malformation of tail and lack of heartbeat in the embryos. This study showed that DEHP is a teratogenic pollutants and the application of FET method is / an alternative method for developmental toxicity tests to predict effects of emerging pollutants on aquatic organisms.

The effect of Palangan fish farms on water quality of Sirvan River was investigated using physicochemical and biological indicators from January 2015 to June 2015. Five stations were determined including 1) before the fish farm 2) after the fish farm effluent 3) sub-branch 4) 100 meter after fish farm effluent and 5) 1000 meters after fish farm effluent. EC showed significant differences in different stations and seasons (P<0.05), but the amounts of temperature, pH and DO showed only seasonal effects (P<0/05) and the levels of ammonia onlyshowed significant differences among different stations (P<0.05). Other parameters showed no significant differences in stations or seasons (p>0.05). According to the water quality index (WQI), the water quality of Sirvan River was better in spring compared to winter. Biological indices including EPT and the frequency were not significantly difference in different seasonal and stations (p>0.05). However, the lowest frequency and EPT index were obtained at 100 meter after fish farm effluent. In conclusion, the results of this study showed that effluent of fish farms in the Sirvan River can be affected in the shortest distance, but water quality becomes acceptable far from the effluent of fish farms. Also, EPT richness and frequency indices confirmed the effects of fish farms effluent on water quality of Sirvan River.

Different factors are involved in the removal of inorganic compounds from the shells of crustaceans. In this study, different effective factors were optimized for the removal of inorganic compounds from the chitin of crab shell Portunus segnis. The best yields were obtained with hydrochloric acid (99.05 ± 0.94). Some organic acid (acid acetic, acid lactic and mixture of them) showed a good potential for inorganic acid substitution for removal of inorganic compounds. In general, an increase in the concentration of acid (up to 10%), ratio powder to acid (w/v)(up to 1:20), temperature (up to 50°C) and time (up to 1h) were associated with the increased the efficiency of this process but excessive amounts of these factors increase the costs and cause negative effects on the chitin structure. Microwave and shakers save time in order to achieve the best efficiency. Moreover, reducing the sample size of powder was correlated with the efficiency increase of the removal of inorganic compounds. The optimization of the extraction method can increase the quality of substance and save the energy, time and cost.

In this study, sea stars Aquilonastra watersi and Patiriella paradoxa were collected from the rocky intertidal area in Tis Port on the western coast.and the rocky shallows depths of 7-8m at Konarak on the Iranian eastern coast of Chabahar Bay, respectively in November 2014. Specimens were collected in plastic sampling boxes containing seawater and transferred to the laboratory of Chabahar Maritime University. The specimens were morphologically assessed. Then in order to examine gene sequences, DNA was extracted by CTAB method and after performing PCR, mitochondrial 16S rRNA gene was sequenced. The phylogenetic-trees for these species were drawn by Maximum Likelihood methods. The evaluations of results showed that despite differences in morphology, A. watersi is sister group of Aquilonastra. Batheri. Based on the results P. paradoxa from present study andP. regularis are in a monophyletic clade, supported by high bootstrap.

In order to investigate seasonal variation of diversity and abundance of Annelida, seasonal sediment sampling was performed on 10 stations with depths of 1, 5, 10 and 20 meters in the coastal area of Sari, Iran in 2015-2016. The results led to the identification of 8 genera and species of Annelida belonging to four families of Polychaeta and two families of Oligochaeta. The highest average annual abundance belonged to Streblospio gynobranchiata and the lowest average belonged to Prenereis sp. The average frequency of the Annelida was significantly and positively correlated with the percentage of the sand and the total amount of organic matter in sediments. The Shannon-Wiener and Margalef Indices showed that, the Annelida had the highest diversity in summer and the lowest species diversity in winter. The Simpson Heterogeneity Index showed the highest amount in the estuary on winter, and heterogeneity showed reduction with increasing the depth. The value of the brillouin index was increased along with the increase of the depth of the stations. The results of this research indicated that the diversity of Polychaeta and Oligochaeta in the study area is reduced compared to previous studies, while the prevalence of dominant species showed a significant increase.

The present study investigated the inhibitory effects of the oral disk extract of sea anemone, Stichodactlya haddoni on acetylcholinesterase and caspase activity. The sea anemone samples were obtained from the intertidal zone of the Hormuz Island in the Persian Gulf. Millipore ultrafiltration was carried out to separate different fractions of the crude extract. Ellman method was used to measure acetylcholinesterase inhibition. The activity of caspase 3 was measured using a calorimetric assay kit of Caspase in breast cancer cell MCF-7. At the end of the experiment, the highest percentage of inhibition of the acetylcholinesterase was observed in 6 mg/ml of the 30-100 kDa fraction (p<0.05). The activity of caspase 3 in MCF-7 treated with concentrations of 400, 600 and 800 μg/ml from the fraction 100-30 kDa were significantly different after 12, 24 and 48 hours (p<0.05). The concentration of 600 μg/ml in the desired fraction showed the highest caspase activity after all the three mentioned times. In conclusion, the protein toxins of the sea anemone, S. haddoni, with a molecular weight of 30 to 100 kD can have anti-Alzheimer's effects by inhibiting acetylcholinesterase enzyme and the lethality effects on the breast cancer cell by activating caspase 3 and possibly inducing apoptosis.

The present study aimed to assess the anatomical and histological structure of kidney and gill in Chiloscyllium arabicum from the Persian Gulf. In this regards, 50 individuals of C. arabicum were caught alive at the north of the Persian Gulf and moved to laboratory. The fish were dissected and samples were taken from kidney and gill and fixed in bouin’s solution for 72h. Thereafter, samples were passed through ethanol, xylem and paraffin using tissue possessor apparatus. Then, 5-6 µm sections of tissues were prepared using rotary microtome and stained with hematoxylin and eosin. Stained tissue sections were studied under the light microscope. According to the results, the kidney consisted of head, body and tail in C. arabicum. The kidney consisted of two functional parts including hematopoietic and excretory sections. In excretory section renal corpuscles and urinary tubules were coated with cuboidal epithelial cells containing spherical nucleus. The gill in C. arabicum consisted of gill filaments and gill lamellae coated with pillar and Pevment cells. In conclusion, the morphohistological structure of gill and kidney in C. arabicum was similar to those in teleost.

The aim of this study was to evaluate the effects of Lactobacillus plantarum supplementation as probiotic on body composition, growth performance, nutrient efficiency indices, and survival in Astacus leptodactylus. For this purpose, 96 crayfishes (27.88 ± 0.27) were randomly distributed into twelve 100-liter fiberglass tanks, (eight crayfish per tank). Crayfishes were fed with different levels of L. plantarum inclusion comprising 0 (control), 107 (T1), 108 (T2) and 109 (T3) CFU g-1 diet for97 days. Feeding was conducted at a rate 1.5 % of body weight on a daily basis at 9 am and 4 pm. At the end of the feeding trials, crayfish in the T3 showed significantly higher protein and lipid levels compared to the control (P < 0.05). Moreover, protein and lipid efficiency ratio (PPV and LPV respectively) were enhanced in the T3 compared to the control (P < 0.05). In the present study, none of the probiotic supplemented groups showed significant differences in the growth performance parameters and survival rate compared to the control (P > 0.05). These results revealed efficiency of L. plantarum as probiotic on body composition and nutrient efficiency indices in A. leptodactylus.

The present study evaluated the effect of dietary waste date meal (WDM) on body chemical composition and fatty acids profile of fingerling cyprinus carpio. Fish were fed with fFour experimental diets with three replicates including control treatment (no additional WDM; T1), 5% WDM (50 gr/kg; T2), 10% WDM (100 gr/kg; T3) and 15% WDM (150 gr/kg; T4). Totally, 168 fish with initial weight of 2.44±0.02 g were fed at a rate of 5 % body weight 3 times per day for 12 weeks. No significant differences were found in body composition among treatments (P>0.05). All of the body fatty acids showed significant differences among different treatments (P<0.05). The highest amounts of MUFA+PUFA, PUFA/SFA, MUFA+PUFA/SFA, ω3, and EPA+DHA were observed in control treatment (T1), and treatment (T2) with 5% WDM showed the lowest amounts of MUFA, PUFA, MUFA+PUFA, PUFA/SFA, MUFA+PUFA/SFA, ω3, ω3/ω6, DHA/EPA and EPA+DHA except for SFA and ω6/ω3 that showed the highest values than other treatments. Atherogenic index (AI) showed no significant differences among different treatments (P>0.05), but significant differences were observed in Thrombogenic index (TI) among different experimental treatments (P<0.05). The 5% WDM and control treatments showed the highest and lowest values of both indices, respectively. Generally, treatments of 10 and 15% WDM (T3 amdT4) showed moderate performance compared to other experimental treatments. In conclusion, diatary WDM can improve the chemical body composition and saturated and unsaturated fatty acids contents of common carp fingerlings

An experiment was conducted to evaluate the effect of nutrient supplement symbiotic on growth performance and hematological indices in rainbow trout (Onchorhynchus mykiss). Fish were fed with three experimental diets contained 0.5,1 and 1.5 g synbiotic per kg feed and a control diet with no synbiotic for 60 days. All three experimental treatments showed significantly higher final mean weight and specific growth rate compared to control treatment. Moreover, all three experimental treatments supplemented with synbiotic showed significant (p<0.05) increases in white blood cell, red blood cell, Haemoglobin and Haematocrit compared to control treatment.

Aquarium fish culture is done for financial and decorative purposes. Aquarium fish culture has its special problems such as parasitic diseases that are very important issues in this field that can make a significant decrease in growth and even death in infested fishes. Current study was done for diagnosis of common ecto-parasites on gill and skin of aquarium fishes including Pterophyllum scalar, Systonus tetrazona, Cyprinus carpio, and Synspilus vieja. Totally, 120 individuals from different culture centers in Shahrekord were randomly chosen, and examined for the presence of ecto- parasites sporadically. Results obtained from this study showed that 66 of 120 samples (55%) were infested. Isolated parasites included Tricodina pediculus, Ichthyophthrius multifilis from protozoans and Chilodonella andDactylogyrus from monogenea trematodes. The most parasitic infection rate was 86.6% for Cyprinus carpio and the least parasitic infection was 33.3% in Synspilus vieja. This study showed the high prevalence of ecto- parasites in the studied arae that must be taken into account.

The aim of this study was to identify the morphological parameters effective insexual dimorphism in Gambusia holbrooki, as a model but invasive livebearer species in Iranian inland waters, using landmark morphometric truss network system. The linear discriminant analysis showed an average percentage of specimens classified of 100% for morphometric characters indicating a high rate of correct classification of individuals into their original populations. The significant differences between two sexes were observed in the head length, head width, body depth, pre-dorsal length, pre-ventral length, pre-anal length, fork length, dorsal fin length, anal fin length, caudal-peduncle depth and caudal-peduncle length.