مجله علوم و فنون دریایی
سال دوازدهم شماره 1 (بهار 1392)

Common kilka, Clupeonella cultriventris is an economic fish in Caspian sea and we investigate population genetic structure of common kilka in the South Caspian Sea costline (Mazandaran province) using microsatellite markers. Totally, 60 individuals of adult common kilka from two seasons were sampled. Eight sets of microsatellite primers were developed from American shad and Pacific herring tested on genomic DNA of common kilka. At this point only the five successfully used primer sets and were used to analyze the genetic variation in adultsof the common kilka population. Analyses revealed that average of alleles per locus was 11.7 (Na range 6 to 17 alleles per locus). Both of sampled seasons contained private alleles. Average observed and expected heterozygosity were 0.543 and 0.866 respectively. Deviations from Hardy-Weinberg equilibrium were in most cases (P<0.01). Basis on AMOVA for both FST values among pairs them indicated a significant difference between the two seasons (P≤0.01). These results support the existence of different genetic populations along the South Caspian Sea costline (Mazandaran province) in different seasons.

Fourfinger Threadfin in shallow coastal waters with sandy or muddy bottom and into the lives of the rivers. The fish in the coastal areas of tropical and subtropical areas of the environment. The family of 7 genera and 35 species have been identified in the warm waters. Persian Gulf fish are apart from the economic elite. Sampled using boats equipped with fishing hooks gill net and sometimes in the Persian Gulf was. And was amplified using the number six position. The highest number of alleles observed in the samples and place Eletet2 Bushehr (5 alleles) and the lowest in the province is the place Eletet16.0 and the samples (one allele). Ho Eletet16.0 samples collected in the range of the lowest position of the province and the province is the highest position Eletet16.0. Shannon index Eletet2 highest position in the province) 1.494 (and its lowest position in the province Eletet17 (0.637) is. AMOVA tests based on risk level 0.01 differences between samples (%76), the difference between the groups (regions) (%0), differences between regions (%24) was calculated. similar genetic criteria Nei, (1972) The province of Khuzestan and Bushehr specimens (0.486) and genetic distance between samples of Khuzestan and Bushehr (0.615) exists. In the present study, heterozygosity at the highest position in the province of Bushehr is Eletet2. The highest observed heterozygosity (Ho), 0.923 is the position Eletet16.0 and Bushehr specimens. The amount of heterozygosity observed in this study is more indicative of the amount expected heterozygosity genetic variability due to fish migration in the near and far and free access to water (high gene flow) is. The results suggest that it is probably a fish population in the areas of Fourfinger Threadfin conventional fisheries management perspective there is any, is the same.

This study was conducted to investigate the effects of Artemia enriched with betaine andconcentrated diet containing betaine on growth performance, survival and resistance to salinity (10 and 45 ppt), temperature (42°C) and formalin (150 ppm) stresses and body composition in Indian white prawn (Fenneropenaeus indicus) larvae. A complete randomized design with four replicates per treatment in twelve 18-l tanks was chosen. Treatments were: Artemia nauplii and concentrated diet (control); Artemia nauplii enriched with betaine andconcentrated diet (treatment 1); Artemia nauplii andconcentrated diet containing betaine (0.8%) (treatment 2) and Artemia nauplii enriched with betaine andconcentrated diet containing betaine (0.8%) (treatment 3). The larvae were fed 6 times per day at 4-h intervals. There were significant differences in growth and survival rate between the treatments containing betaine (treatment 1, 2 and 3) and control treatment (p<0.05). Furthermore, the larvae that were fed with betaine had significantly higher survival rate in stress resistance tests (p<0.05). The proximate analysis of shrimp carcass did not show significant difference between treatments (p>0.05). The result of the present study indicated that the enrichment of Artemia nauplii with betaine and dietary supplementation of Betaine have positive effects on growth factors, survival and resistance to environmental stresses in Indian white prawn.

Nest site location in reptiles is an important stage of their life cycle because environmental factors influence embryo survivorship, incubation quality and sex ratio. For studying effective factors on nest site location in the hawksbill turtle, we measured temperature, moisture, beach slope, particle size of sand and vegetation related to 35 nests in Shidvar Island. In this Island, most nests were in northern beach which has a relatively steep slope. In this slope energy costs and probability of females and hatchlings predation is low. In addition hawksbills preferred to nest amongst vegetation. Of the environmental evaluated, slope appears to have the greatest influence on nest site location, because it is associated with nest elevation and hatching success is higher from nests closest to suitable elevation. It is believed that sea turtles may use multiple cues for nest site location and use a threshold that must be reached for each environmental factor before the turtle initiates nest excavation.

The study took place to survey the changes in diversity and distribution of Polychaetes in fishing area of Bahrakan, due to the trawling. Sampling was taken before (15 May) of trawling and two weeks (5 Sep) and three months (14 Nov) after trawling in 2010, in three period in Bahrakan coast. Therefore, eighteen stations placed with the depth of 6 meters and 10 meters.The amount abundance Polychaetes had decreased significantlyin both depths two weeks after trawling (P<0.05). Also in 6m depth, no significant difference was observed between abundance Polychaetes in two weeks and three months after the trawling (p>0.05). Only in 10m depth, abundance Polychaetes after three months comparing to two weeks after trawling had increased significantly (p<0.05). Changing biomass Polychaetes was similar to Changing abundance. After the trawling, small size individuals became dominant.Abundance Species ofCossura longicirrattahad increased in both depths in two weeks after the trawling. Also in both depths, Shannon Diversity and Margalef Species Richness indices showedprocess decreasing and Simpson dominant Index showedprocess increasing. In both depths, Pielou Evenness Index two after trawling had increased. While, after three months comparing to two weeks after trawling had decreased and most effects of trawling were on 6m depth.

The most important factors controlling cladocerans production, growth, and morphometric characters are temperature, food quantity and quality and photoperiod. Effects of temperature and photoperiod on production, and morphometric characters of cladoceran, Ceriodaphnia quadrangular, were examined by culturing on green algae Scenedesmus quadricauda in 250 ml conical flasks (150 ml water). Treatments used for temperature (˚C)and photoperiod (light hours:dark hours) were 20,25,30 (˚C) and 12:12,24:0 and 0:24, respectively. The maximum population density (5.51 ind./ml) obtained at 24:0 and 30 (˚C), while maximum body length (731 µm) and maximum body width (491 µm) obtained at 0:24 and 20 (˚C). Correspondingly, the maximum adult (61 %), maximum neonate (39 %) and young (9 %) in population under culture conditions of 0:24, 12:12,24:0 (L: D) and 20 (˚C) obtained, respectively. Overall, this research showed that growth and reproduction of Ceriodaphniaquadrangula gave better performance at 25 (˚C)and 24:0, light: dark photoperiod.