فصلنامه بوم شناسی آبزیان
سال ششم شماره 3 (پیاپی 603، زمستان 1395)

Algae are composed of a diverse group of various aquatic organisms. Secondary or primary metabolites from these organisms may be potential bioactive compounds of interest for use in the development of new pharmaceutical agents. In this research, four species of marine algae, Ulva lactuca, Padina pavonica, Colpomenia sinuosa and Cystoseira myrica, isolated from Persian Gulf coasts were evaluated for their antimicrobial activities, using disk diffusion and Minimum Inhibitory Concentration assays. Extracts of the algae selected for this study were prepared using methanol, n-hexane and ethyl acetate as solvents. Best results were shown by the ethyl acetate extracts of Ulva lactuca against bacterial strains. Results also indicated that the bacteria were more sensitive against algal extracts than fungi studied. The lowest value for MIC test was belonged to the green alga, Ulva lactuca, in accordance with growth inhibition zone values obtained from disk diffusion assay. Based on present results, gram-positive bacteria were more sensitive to the algal extracts than gram-negative ones.

Chabahar Bay near Makran Sea, with the ports of transactions, has always been under the influence of annual monsoon the Indian Ocean. Density changes and heavy metals copper and zinc of Chabahar bay subtidal sediments were studied in 22 stations and three seasons that include: pre-monsoon, monsoon and post-monsoon during 2014. Polychaeta abundances mean were for premonsoon 1261.49±38.81, monsoon 513.81±65.6, postmonsoon 630.45± 73.84 ind/m2 that significant difference was observed between stations and seasons (p<0.05). Metals copper and zinc had fluctuations in three seasons, but despite the significant differences between the stations, there was no significant difference between seasons. Metals mean in preM, M, postM respectively for Cu include 19.89±3.34,14.42±4.47,12.9±3.4 and for Zn 73.42±5.51, 66.04±6.37, 61.72±4.86 µg/g dry weight that only in three stations and only in Cu, concentrations were higher than ERL but in total Chabahar bay metal mean were lower than ERL. Significance correlations were not observed between Polychaeta density and heavy metals except for copper in pre-monsoon. The results showed the impact of monsoon currents in the distribution pattern of polychaete and heavy metals and also were no significant differences in the relationship between density and concentration of can be as results of the low concentration heavy metals in sediments of international standards and other environmental factors on polychaeta density.

The aim of the present study was to evaluate the illegal Silver pomfret catch by fixed gill-nets in Hormozgan inshore waters (Qeshm Island). Sampling was performed in Bandar Laft estuaries through three fishing boats between April to July 2015. The fishing gears were the nylon mono-filament fixed gill-net with 6.5 cm mesh size (bar), 200 m length and 8-10 m height. The non-parametric bootstrap method was utilized to estimate the average catch rate (± Confidence interval) of commercial fish caught. After forty-eight landings, the catch composition included 14 teleost fish species and 1 invertebrate. The catch composition by weight also included 59.57 % target species (P. argenteus) and 40.43 % incidental catch. For incidental fish caught, M. cephalus and P. sextarius with 39.58 % and 6.83 % had highest and lowest occurrence and L. johnii with 4.57 % had highest weight percentage. The catch rate (kg.boat-1.day-1) of P. argenteus was calculated between 9.125 and 16.941. Using Monte Carlo procedure, annual illegal Silver pomfret catch was estimated between 265.690 to 303.701 tonnes (α=0.05).

The accumulation of the heavy metals Cd, Zn, Cu, and Pb were surveyed in the samples of mantle tissues, crusts and so the habitat sediments of C. fluminalis to reveal the probable biomonitoring rule of the bivalve in the ecosystem. The warm-cold seasonally samplings were carried out over the stations of Zayandeh-Roud River in Safi'eh, Isfahan province, during 2014. The warm and cold seasonal average results from the initially acidic digested prepared samples of the bivalves (mantle and crust) and the sediments were recorded by furnace atomic absorption spectrometry methods. The results illustrated that the average of Zn accumulation has the maximum value in the sediment samples of warm-season samples (28.8±3.80 µg.g dry w.-1) as well the cold-season (16.9±1.23 µg.g dry w.-1). Furthermore, the accumulation values of zinc in the warm-season and the cold-season samples had the maximum values in the tissue samples with values 206.2±33.77 and 89.1 ± 19.02 µg.g dry w.-1 and the crust samples with values 35.6 ± 3.06 and 33.1 ± 3.10 µg.g dry w.-1 , respectively. Except for heavy metal Cd, the similarity values of the metals Zn, Pb and Cd in both sediment samples and the crusts of C. fluminalis demonstrates the relative extents of the heavy metals in the habitat of the bivalves with no seasonal effect on the values fluctuation. The levels of measured samples of mantles revealed the tissues of living C. fluminalis rule as the bioaccumulation of the metals Zn, Pb, Cu and Cd in the river ecosystem.

Golbolagh Reservoir is located the east of Kurdistan province with 8.1 Million cubic meters' capacity. This study was conducted for one year to investigate the population structure, diversity and seasonal change of phytoplankton of Golbolagh Lake. Some physicochemical parameters of this water body at each sampling site were studied. In this study, 6 phylum, 22 families and 23 genus of phytoplankton were identified; 10 genus belonging to Bacillariophyta, 6 genus belonging to Chlorophyta, 4 genus belonging to Cyanophyta, 1 genus belonging to Euglenaophyta, one genus belonging to Crysophyta and one genus belonging to Dynophyta. The mean annual density of phytoplankton was 1662 (cell/ml). The average density of Bacillariophyta was 1196 per ml with 30 percent frequency, while average density of Euglenaophyta was 791 per ml with 2 percent frequency, respectively and the highest and lowest density and abundance of phytoplankton, they were allocated and were statistically significant compared to other branches (P <0/05). Margalef richness and Shannon-Wiener diversity indexes were calculated. The two index were compared between seasons sampling and between stations, with no observed significant difference between stations, however, there was a significant difference between seasons sampling (P <0/05).

In the present study, the process of the skull development and calcification in Persian sturgeon (Acipenser persicus) was studied. Development of cartilage started after hatching around the head and notochord (10.6 mm, total length, TL) and the first calcification process occurred in dermopalatine and dentary bone jaw coincident with mixing feeding. The appearance of dermal skeletal on the body divided into three stages: (a) the yolk-sac (comprised of hatching to the late larval stage (12 DPH, 16 mm TL) in which no calcified structures became visible and the cartilaginous elements of skull with feeding and breathing roles have appeared. (b) the larval stage (between 16 and 20.25 mm, 23 DPH) in which, the first calcification process related to feeding and breathing occurred and weak mineralized dermal bones such as subopercle and supracleithrum developed; and (c) the metamorphosis stage between 27.25 and 83.3 mm TL) during which the formation of mineralized dermal bones occurred between 32 and 50 days post-hatching, and teeth were disappeared on dentary and dermopalatine bones. The results of this study could be useful for decreasing the larval mortality and improving the stock conservation programme of Persian sturgeon.

Diet of kingfish was examined in the Iranian coastal waters in the Persian Gulf and Oman Sea during the year 2005-08. With the examination of 1655 kingfish stomachs caught by drifting gillnets, it was revealed that this species fed three groups of preys including fish, Cephalopods, and Crustaceans, of which the fish group accounted for the highest in the frequency of number (99.3%) and in the frequency of occurrence (99.1%). Nine families for the fish group, one family for Cephalopods and one family of Crustaceans were identified, with totally fifteen species were identifiable. In fish group, Engraulididae and Clupeidae families had the highest frequency of number (22% and 13.5% in respective family) and the highest frequency of occurrence (8.4% and 14.4% of the total stomachs examined in respective family), which Clupeidae seems to be a preferred food for kingfish in the coastal waters. Feeding intensity of kingfish is higher when the peaks of small pelagic catches occurred in spring and winter in the coastal waters. Because of the importance of Sardines and Anchovies in the feeding of kingfish, it is necessary to harvest the valuable resource of the small pelagic fish.

Paraben compounds are used widely as preservatives to inhibit microbial growth and extend used in pharmaceuticals, hygienic, cosmetics, care products. They pose the potential for reproductive toxicity for users. This paper provides an overview of the applications of histopathological biomarkers in reproductive toxicity in zebrafish caused by methylparaben. The present study investigated the changes in ovarian histopathology and Gonad Somatic Index (GSI) in zebrafish (Danio rerio</em>) adult female after exposure to 0.001, 0.01, 1 and 10 mg/L methylparaben for 3 weeks in semi-static condition. Histological preparations were stained with Hematoxylin & Eosin. The results showed that Treatment at 0.001 to 10 mg/L of methylparaben had no significant effect on the survival, and condition factor. But in all treatments, GSI decreased and ovarian complications include wrinkled ooplasm, impaired yolk production, granulomatous inflammation and proteinaceous fluid were observed in the interstitial space of treated zebrafish ovaries. Also, atresia of vitellogenic oocytes was determined. These data show that an increase in atretic follicles has negative effects on zebrafish fertility and continuous exposure to subacute sublethal concentrations of methylparaben increase estrogenic and irreversible effects on the reproductive in female zebrafish.

In this study, the effects of sublethal concentrations of the Endosulfan on gene expression of hypoxia-inducible factor (HIF-1 α, HIF-2 α) and vascular endothelial growth factor (VEGF) in the gill tissue of Persian sturgeon fingerling (Acipenser persicus</em>) were studied. A total of 360 sturgeons (average weight of 2 ± 0.12 g) exposed to concentrations of 10, 20 and 40 micrograms per liter and VEGF and HIFs after 1, 2, 7 and 14 days of exposure were evaluated. The relative expression of HIF-1 α significantly increased in exposed samples in comparison to the control group. Moreover, the expression of HIF-1, 2 α in the highest concentration of toxin (40 micrograms per liter) had significantly different from other concentrations and this difference was seen in all of the sampling points. The results showed that the Endosulfan which is one of the most important pollutants in aquatic ecosystems significantly stimulates the expression of genes involved in hypoxia and angiogenesis is the gill. According to the results of this study, the devastating impact of Endosulfan on the aquatic ecosystem can be found over the past, so the basic requirement to more effective management about the use of these pesticides more than ever felt.

In regarding to study the effect of biological parameters of female rainbow trout (Oncorhynchus mykiss</em>) brood stocks on girt, 30 specimen of rainbow trout brood stocks were selected from 3 different age class (3, 4, 5 years). The results showed, maximum of girt 36.35± 0.35cm , ovary weight 600±11.25 gr, hatching 90±4 % and larvae weight after hatching 0.15±0.01 were in 5 and 3 years old brood stocks, respectively. The results  showed significant  differences between 3,4 and 5 years old  brood stocks for this instances (P</em><0.05). Maximum of number of eggs in each gram 15±0. 26 Registered in 3 and 5 years old brood stocks, respectively. Maximum absolute fecundity, relative fecundity, and working fecundity were recorded in 4 and 3 years old brood stocks, respectively. The study pointed significant difference between investigated brood stocks (p<0.05). Maximum of larvae survival percentage were observed in 4 and 3 years old brood stocks, respectively. The results showed no significant difference between 5 and 3 years old brood stocks, but for 4 and 5 years old brood stocks was saw significant difference (P</em><0.05). Maximum of gonadosomatic index were observed in 5 and 3 years old brood stocks, respectively. Although gonadosomatic index between 4 and 5 years old fish showed no significant difference, but the study showed significant difference for 3 years old brood stocks (P</em><0.05).

In this study abundance and composition of Vibrio </em>spp. In water and sediment of inlet Chanel and shrimp pond during the entire crop cycle were done in Gowater shrimp complex. Samples of  source (Inlet chanel) water and pond water werecollected one day prior to filling the pond with water and thereafter at  twenty day intervals after stocking at three pre-determined sampling  locations in two ponds (pond 1 and pond 2; sampling points denoted as A, B and C in each pond) and one locations in the source water (Inlet Chanel).Total Vibrio </em>like organisms (TVLO) wasenumerated on Vibrio-selective medium- thiosulphate citrate bile-salt sucrose agar (TCBS; HiMedia, India).Identification of Vibrio </em>spp. was based on their morphological, and  biochemical characteristics using the Bergey’s Manual of  Determinative Bacteriology. obtained Results during the study revealed, the average total counted vibrio bacterial</em> in rearing water were significantly higher than in source water (P </em>< 0.05).As well as, comparisonin  abundance and composition between two ponds with each other and Inlet Chanel are significantly differentiated. Of course compositions of source water vibrios are similar betweensampling date. The Vibrio </em>community was represented in abundance mainly by V. metschnikovii</em>, V. fluvialis, V. mimicus</em>respectively. Because of pathogenic potential of these bacteria, health management of shrimp pond is very necessary.

According to importance of Chabahar Bay as one of the marine strategic areas and need to learn about pollution of this area, in this study, Cu, Ni and Zn concentration was investigated in the soft tissue of chiton Acanthopleura vaillantii</em> from 5 stations in the coast of Chabahar Bay at autumn of 1394. For this purpose, samples were collected and transferred to the laboratory, then after preparation and chemical digestion process, concentration of heavy metal was measured in soft tissue of Chiton by Atomic Absorption spectrophotometer. The results showed that the mean of concentration of heavy metals in soft tissue of Chiton had a pattern just Zn> Ni> Cu. Statistical analysis showed that all stations had significant differences (P<0.05). Concentrations average of Cu, Ni and Zn in 5 stations were measured 5.45 ± 0.12, 15.59 ± 0.22 and 21.25 ± 0.19(µg/g dry wt.) respectively, that chitons of station 1 (Shahid Kalantari pier) was observed the highest and station2 (beach of Maritime University) lowest concentrations of heavy metals. Comparing the results with US FDA, FAO and Iran Standard Institution standards, was showed low accumulations of Cu and Zn metals rather than allowed end of standards, but accumulations of Ni was excessive from allowed end of standards and this pollution can be for human activities such as maritime trade, shipping, municipal and industrial wastewaters and so on.

In this research antibacterial activity of Pseudomonas</em> isolates derived from hepatopancreas of Litopenaeus vannamei</em> were evaluated against pathogenic Vibrio</em> spp. Shrimp samples collected from 9 different ponds in Tiab region- Hormozgan province. Hepatopancreas samples of collected shrimps were inoculated in three different isolation media. Pseudomonas Isolation Agar medium revealed highest yield by isolation of an average 22 pseudomonas</em> isolates. Approximately 40 Pseudomonas</em> isolates were obtained. Results of antibacterial screening experiments by well diffusion method demonstrated antibacterial activity of MR21 and MR35 strains. These producer isolates exhibited the highest antibacterial activity against all target Vibrio</em> species consist of Vibrio parahaemolyticus</em>, V. harveyi</em>, V</em>. anguillarum</em> and V</em>. alginolyticus</em> after 72 hours. Biochemical, morphological and physiological studies showed that MR21 and MR35 strains belong to Pseudomonas aeruginosa. </em>Evaluation of antibacterial activity of potent strains in different media proposed trypticase soy broth as an efficient medium. Assessment of temperature influence on antibacterial activity of potent isolates revealed stability of antibacterial activity in 25˚c, 35˚c, 45˚c. Comparison of antibacterial activity of producer strains in presence of seawater and distilled water showed that seawater could promote antibacterial activity. Analysis of growth curve revealed that potent isolates entered to stationary phase after 24 hours. According to achieved results P. aeruginosa</em> MR35 and P. aeruginosa</em> MR21 can considered as potential probiotic isolates for further studies.

This study was conducted to determine concentration of lead (Pb) in the liver of flathead (Platycephalus indicus</em>) in Minab, Qeshm Island and Khamir Port in the Persian Gulf during winter and summer (n= 30).  Concentration of lead was measured using Atomic Absorption Spectrometry (AAS). The results showed that, there were significant differences between stations for the concentration of lead in liver of P. indicus</em> in winter and summer (P<0.05). There were not significant differences between concentration of lead in liver of males and females (P> 0.05). The results showed that, marine pollution (aquaculture, urban and industrial activities) in different area in the Persian Gulf and seasons are effective factors on bioaccumulation of lead in P. indicus.</em>

Aim of this study was to evaluate the effects of diazinon toxicity (LC50) on silver carp and roach fry for measuring resistnce of these fishes. Roach with an average weight of 7 ± 1 g and silver carp 30 ± 1 g were studied to measuring lethal concentration LC50 at 96 hours. Experiment was used with a completely randomized design in 9 treatments and 3 replications for both silver carp and roach. The results showed LC50in silver carp 3.93 (2. 94-4. 99) mg/l was more than roach 1.71 (1.20-2.23) mg/l that means higher diazinon resistance of silver carp than roach.