JOURNAL OF MARINE SCIENCES AND TECHNOLOGY
Year:2015 | Volume:14 | Issue:3|Papers Count:14

Full Text [PDF 981KB] Polymorphism between the species of sturgeons due to natural hybridization, human manipulations and escaping hybrids from farms makes difficult their identification. Hence, this research was conducted to study the head shape differences between the Great beluga (Huso huso), Sibrean sturgeon (Acipenser baerii) and their diploid and triploid hybrids (male Siberian sturgeon ´ female Beluga) using geometric morphometric technique. In total 120 specimens (30 specimens from each group) were sampled. Nine, twelve and thirteen landmark points were digitized on 2D images of the lateral, dorsal and ventral views of their head, respectively, using TpsDig2. Landmark data after GPA, analyzed using CVA and MANOVA. The results showed significant differences among studied groups in the terms of head shapes in all three views.

Full Text [PDF 1371KB] A general description of distribution patterns of rocky shore bivalvia along the whole Hormuz Island coasts is given to provide the context for comparisons of distribution patterns of this intertidal organisms. In order to test if there was any variation in species distribution and abundance from upper to lower intertidal zone (littoral zone) along the entire rocky shores of the Hormuz Island, three main regions were studied from summer 2005 to spring 2006 (west, south and south-eastern) and 3 transects were sampled in each region. At each of the 9 transects the shore was levelled and a general qualitative description was made. Upper zone characterized by the presence of Saccostrea cucullata. Midlittoral zone was essentially dominated by Saccostrea cucullata. The distribution patterns observed on the lower zone didn’t show a similarity between rocky shores located in the Hormuz Island. It has also given important information on abundance and distribution of bivalvia that revealed seasonal distribution in rocky shores of the Hormuz Island. According to this results abundance of bivalvia was markedly higher in summer compared to winter.

Full Text [PDF 541KB] The present study was carried out in two Station in Costal of the Khuzestan province (including Abadan, and Hendizan) using the commercial catch data. This project one year during 2007-2008, in addition over 2300fish caught was biometry. The growth and mortality parameters of Silver pomfert, infinity length, L∞: 35.5., growth curvature, K: 0.56., length in zero time, t0: - 0.32., total mortality, Z: 3.06., natural mortality, M: 1.07., fishing mortality, F: 1.99 and Exploitation ratio, E: 0.65 respectively were estimated. By used analysis method, Y' /R=0.019, B' /R=0.10, Exploitation rate, U: 0.61, MSY= 440 T and MCY=290 T were estimated respectively. Result in this study showed exploitation ratio the Silver pomfert stock is over fishing and decrease exploitation ratio proposed.

Full Text [PDF 358KB] 16S rRNA is one of the components of the ribosome and widely used in phylogenetic studies of closely related species and especially related species Crassostrea. Nucleotide sequence polymorphism associated with 16S rRNA gene of mitochondrial genome of Persian Gulf Oyster (Crassostrea sp.), examined in 30 samples collected from Badar-e Emam Khomeini oysters. Through a primer PCR chain reaction was performed for all samples and product of PCR were Automated sequencing. Then the data obtained were analyzed by the programs and software. For the gene studied only there was 2 mutation and Nucleotide diversity (Pi) 0.00061 calculated. Among the 30 samples, 3 haplotypes were detected and average haplotype diversity (Hd) 0.195 were calculated. The haplotypes obtained in this study were first registered in the gene bank. Phylogeny trees drived from 16S rRNA gene sequencing showed no clear separation of the samples in the Bandar-e Imam Khomeini region. The results of this study showed that there is low sequence differentiation in the study population in Bandar-e Imam Khomeini.

Full Text [PDF 825KB] One of the most important topics in river engineering is protection of banks. Because of change in flow characeristics the banks of rivers will be remove that it is very sever. Use of spur dikes is one of the common methods for protection of banks but there is a problem in this field that is protection of spur dikes which there isnt many reserch about its. Because the spur dikes are very useful in the bends therefore this research carried out in the 90 degree bends. In this resech the goal is investigation of the of spurdikes angel on stability if riprap. For achievement of this goal use three length of nose of spur dike ( 50%, 75% and 100% of body length of spur dike) and three diameter of rip rap (1.51cm, 1.12cm, 0.72cm). the results showed that in all of the experiments increase in angel of nose cause decrese in froude number of flow, densimetric froud number of sediment in failure of riprap and then decrese of riprap stability.

Full Text [PDF 436KB] Due to their toxicities, oil pollutions and its derivatives such as anthracene are one of the most important issues of environmental researches all over the world. Oil hydrocarbons in contaminated soils, sediments and water can be degraded by microorganisms. Removal of hydrocarbons from aqueous solutions is also possible using cultured bacteria. In this study, the anthracene bioremediation by Bacillus pumilus isolated from oil sediments of Imam Khomeini port, was investigated. This bacterium made no clear halo on blood agar medium and couldn’t disperse the mineral oil but created a halo with a diameter of 0.5 cm on the surface of crude oil. As a result, the bacterium was detected as a non-producing biosurfactant species. The optical density of this species in the sample containing 30 mg/l of anthracene finally reached to 0.086. Measurement of anthracene degradation by HPLC showed that %40.833 of mentioned hydrocarbon was removed after 5 days. Therefore, the results indicate that the isolated bacterium can probably behave the same in the natural environment and could have the potential in bioremediation of this pollutant from environments.

Full Text [PDF 416KB] In this study, different levels of vitamin C (L-ascorbyl-2-polyphosphate) on the hatching efficiency and obtained Artemia nauplii survival were examined at different temperatures. In the first experiment, the effect of different amounts of vitamin C (0, 500, 1000 ppm) on hatching percentage of the Maharloo Lake Artemia cyst was examined with 6 replicates. Results of the first experiment showed that different amounts of vitamin C had no significant effect on hatching percentage. In the second experiment, the effect of different temperatures on the percentage of survival of Artemia nauplii was studied. In this experiment, obtained nauplii from first experiment were put in 3 different temperatures (1, 4, 16 ºC) with 6 replicates for 48 hours, then percentage of survival of Artemia nauplii accounted. Result of the second experiment showed that interaction of vitamin C and different temperatures had no significant on the survival rate of Artemia nauplii. Different amounts of vitamin C (0, 500, 1000 ppm) had no significant difference on the percentage of survival of the Artemia nauplii, but different temperatures had significant effect on survival rate. Results of these experiments showed that increase of the amount of vitamin C had significant difference on hatching percentage of the Maharloo Artemia cyst, no significant effect on survival rate of Artemia nauplii. Also it is found that survival rate of Artemia nauplii in 16 ºC temperatures was more than 1 and 4 ºC temperatures.

Full Text [PDF 507KB] The population dynamics depend on their environment and habitat stability and environmental conditions are the main element effecting biodiversity and richness. The main objective of this study is assessment of biodiversity of intertidal crabs in chabahar bay. During this research TOM, Moisture, Density, Dominance, Richness and Evenness have measured. For this purpose, Sampling were carried out at 3 stations, Tiss, Jazireh Kharchang and Konarak, in one period in July 2009. Totally, 7 species recorded, belonged to the family Ocypodidae. The results of biodiversity indices' in 3 Stations have been shown which Jazireh Kharchang with 5 species and Konarak with 1 species have the highest and lowest diversity, respectively. Whereas, The Percentage of TOM and Grain Size showed significant differences between the 3 Stations, while the highest TOM and lowest sand Percentages observed in Jazireh Kharchang.

Full Text [PDF 366KB] For study the reproductive physiological differences between fall and spring migrants of Caspian Lamprey (Caspiomyzon wagneri) in the south of Caspian Sea, Shirood River.15 & 16 fish in autumn and spring were collected. Hormone measured by ELIZA method, and for histological study conventional method and Hematoxilin-eosin staining was performed. In the both spring and autumn season Fishes are in the final reproductive stage, based on Histological studies of gonads, but did not spawning yet. Concentration of testosterone, 17b-estradiol and progesterone hormones of males, in both season, are higher than females, with an exception. Progesterone of females in spring higher than males. Testosterone of males and females is not different between autumn and spring. 17b-estradiol concentrations of females are similar in to two seasons but in autumn males had higher concentrations of 17b-estradiol. Progesterone of males and females was different in both seasons. Generally, the results indicated some reproduction signs of Caspian Lamprey in both fall and spring season.