Molecular diversity of Symbiodinium spp. within six coral species in Larak Island, the Persian Gulf

Reef-building coral harbor communities of photosynthetic taxa of the genus Symbiodinium (zooxanthellae). The genus Symbiodinium is currently classified into nine genetic clades (A–I). Various corals harbor different Symbiodinium clades; some show specificity to a single strain. Coral and their zooxanthellae are sensitive to environmental stresses. In the Persian Gulf, coral reefs are subject to harsh environmental conditions including extreme temperatures and high salinity. This is the first study to use clade specific primers to clarify the diversity of Symbiodinium in each coral species of Larak Island. For this purpose six coral species were collected at two different locations in Larak Island. After DNA extraction, PCR amplification was performed using clade specific primers. The results showed that multiple Symbiodinium clades are hosted by most coral species. In addition, among thirteen obtained Symbiodinium sequences, the frequency of either tree [sic] clades, A, C and D was almost the same. Corals species may contain different clades of Symbiodinium depending on the region and on the tolerance characteristics of each clade. Thus, knowledge of zooxanthellae diversity associated with scleractinian can contribute to a better understanding of the sensitivity of corals to environmental conditions

Population genetic structure of the white sardine, Sardinella albella, in the Persian Gulf and Sea of Oman by analysis of mitochondrial control region

Several studies on the white sardine: Sardinella albella, have focused on the identification of stock composition and behavior. In this study population genetic structure and historical demography of S. albella along the cost of the Persian Gulf and Sea of Oman were investigated with a 500-bp segment of mt-DNA control region. In total 40 samples were collected from 3 locations: Jask in Sea of Oman, Qeshm in Strait of Hormuz and Lengeh in the Persian Gulf during 2012-2013. 33 haplotype were obtained none of which were presented in all sampling sites. Analysis of molecular variance (AMOVA) indicated low genetic differentiation among regions (F_ST=0.024, p<0.05). The average pair wise differences between regional population were small but significant (0.0158-0.165). Molecular variance explained by differences among three regions was significantly different from zero but the F_ST did not show clear phylogeographic isolation. This observation can support the conclusion that S. albella has a widespread dispersal potential

Comparison of antibacterial activities of Ircinia mutans extracts in two different seasons from Kish Island, Persian Gulf, Iran

Sponges, which constitute the phylum Porifera, are the most primitive of the multicellular animals, among all marine organisms screened. Marine sponges produce the largest number of structurally diversified natural products. In this study we investigated in vitro antimicrobial activity of Ircinia mutans collected from the Kish Island in the Persian Gulf against strains of bacteria Escherichia coli (ATCC 15224), Pseudomonas aeruginosa (ATCC 25619), Staphylococcus aureus (ATCC 1764), and Bacillus subtilis spizizenii (ATCC 6633). Diethyl etter, methanol and aqueous extracts of sponge were evaluated by using the Bacterial Broth Dilution Method. The results showed that the aqueous extracts didn’t have any antibacterial activity. Minimum Inhibitory Concentrations (MIC) of the winter diethyl etter extract was 2 mg/ml for E.coli and 20 mg/ml for P. aeruginosa, whereas the summer diethyl etter extract and both of methanol extracts did not show any activity. The MIC and MBC (Minimum Bacterial Concentration) of summer diethyl etter extracts were 2 mg/ml and 3mg/ml against S. aureus; and 5mg/ml and 10mg/ml when tested on B. subtilis. The MIC and MBC of winter diethyl etter extracts were measured as 1.5 mg/ml and 2mg/ml against S. aurous; and 5mg/ml and 10mg/ml when examined on B. subtilis. Summer and winter methanol and aqueous extracts of I. mutans did not show any activity against these bacteria. Therefore secondary metabolite solutions in diethyl etter contain components with antibacterial properties and can be used as antibiotics products

Biodiversity of order Zoantharia in the Persian Gulf: Hormoz Island

The order Zoantharia (Zoanthids) is one of the most neglected orders of Cnidarians in the Persian Gulf. The present study aims to investigate the biodiversity of this order with morphological and molecular examination in Hormoz Island. For this purpose 34 colonies of zoanthids with variety of shape and colors have been collected of intertidal and shallow water region of Hormoz Island. After sampling, morphological characteristic of each specimen were recorded based in situ photographs. Then DNA was extracted using the CTAB- Chloroform method and mt 16s rDNA gene fragment was amplified and sequenced. The results of preliminary morphological identification integrated with mitochondrial marker sequencing demonstrated the presence of at least three different species in Hormoz Island; Zoanthus sansibaricus, Palythoa cf. mutuki and Palythoa tuberculosa. Although at first sight, morphological characteristics were not successful to identify zoanthid to the species level, after molecular identification they establish as reliable criteria to identify and delineate species

Population genetic structure of Neogobius caspius (Eichwald, 1831) in the east and central of the south Caspian Sea using microsatellite markers

Neogobius caspius is a small benthic fish that is native to the Caspian Sea. The importance of this fish is because of it is role as a main food resource of the Sturgeon fish. The genetic diversity of N.caspius populations in the Caspian Sea was studied using microsatellite technique. In the study 95 Samples of Neogobius caspius from two regions (Torkman port and Chalus) in south Caspian Sea were collected. DNA was extracted using 12 pairs of microstellite primers polymerase chain Reaction (PCR) was conducted. DNA Bands were analyzed using uvdoct and GenAlEx software package. Out of 12 microsatellite primers, 11 loci were produced, in which 5 of them were polymorphic, 6 monomorph and one of them showed smear. Average of observed and expected hetrozygosity was 0.798 and 0/843 respectively. Significant genetic differences between 2 regions was observed (P<0.01). Deviations from hardy- Weinberg equilibrium were in all cases. These results indicate that at least, 2 population of Neogobius caspius exist in the south Caspian Sea

The in vivo effect of methyl tert-butyl ether on liver, gills and kidney tissues of Rutilus caspicus

This study was conducted to evaluate histopathological responses in liver, gills and kidney in Rutilus caspicus exposed to concentrations of 50, 100, 150 mg L^-1 of methyl tert-butyl ether, for 7, 14, and 21 days. The experiments were conducted in water temperature of 19±1 °C, dissolved oxygen of 7.6 ± 0.2 mg L^-1 and zero salinity. A total of 156 fish were studied in this experiment. In the first, second and third week of the experiment, three fish were taken randomly from each aquarium. To examine the tissues, the liver, gills and kidney were isolated and prepared for evaluation using standard histological techniques. Tissue damage in the liver includes: blood congestion, congestion of sinusoid, melano macrophage aggregation, hepatocyte hypertrophy, vacuolation, degeneration and cellular necrosis. Gill tissue damage includes: hyperplasia, degeneration lifting, telangiectasis, in secondary lamellae, blood congestion in primary and secondary lamellae, S formation of lamellae, and reduction in length of secondary lamella, lamellar fusion and cellular necrosis. Tissue damage in the kidney includes: tubular shrinkage, blood congestion, melano macrophage aggregation, glomerular shrinkage, cellular necrosis, tubular degeneration, reduction in interstsial cells and interstisial hematopoietic tissue degeneration. The amount of tissue damages in high concentrations of pollutants was high, while gill, liver and kidney in the control group were observed in the normal outline. The results of this study showed that methyl tert-butyl ether (MTBE) can cause damage in vital tissues of R. caspicus and even, eventually lead to death

Present Limits to Heat-Adaptability in Corals and Population-Level Responses to Climate Extremes

Climate change scenarios suggest an increase in tropical ocean temperature by 1–3°C by 2099, potentially killing many coral reefs. But Arabian/Persian Gulf corals already exist in this future thermal environment predicted for most tropical reefs and survived severe bleaching in 2010, one of the hottest years on record. Exposure to 33–35°C was on average twice as long as in non-bleaching years. Gulf corals bleached after exposure to temperatures above 34°C for a total of 8 weeks of which 3 weeks were above 35°C. This is more heat than any other corals can survive, providing an insight into the present limits of holobiont adaptation. We show that average temperatures as well as heat-waves in the Gulf have been increasing, that coral population levels will fluctuate strongly, and reef-building capability will be compromised. This, in combination with ocean acidification and significant local threats posed by rampant coastal development puts even these most heat-adapted corals at risk. WWF considers the Gulf ecoregion as “critically endangered”. We argue here that Gulf corals should be considered for assisted migration to the tropical Indo-Pacific. This would have the double benefit of avoiding local extinction of the world's most heat-adapted holobionts while at the same time introducing their genetic information to populations naïve to such extremes, potentially assisting their survival. Thus, the heat-adaptation acquired by Gulf corals over 6 k, could benefit tropical Indo-Pacific corals who have <100 y until they will experience a similarly harsh climate. Population models suggest that the heat-adapted corals could become dominant on tropical reefs within ∼20 years

Molecular diversity of Symbiodinium spp. within six coral species in Larak Island, the Persian Gulf

Reef-building coral harbor communities of photosynthetic taxa of the genus Symbiodinium (zooxanthellae). The genus Symbiodinium is currently classified into nine genetic clades (A–I). Various corals harbor different Symbiodinium clades; some show specificity to a single strain. Coral and their zooxanthellae are sensitive to environmental stresses. In the Persian Gulf, coral reefs are subject to harsh environmental conditions including extreme temperatures and high salinity. This is the first study to use clade specific primers to clarify the diversity of Symbiodinium in each coral species of Larak Island. For this purpose six coral species were collected at two different locations in Larak Island. After DNA extraction, PCR amplification was performed using clade specific primers. The results showed that multiple Symbiodinium clades are hosted by most coral species. In addition, among thirteen obtained Symbiodinium sequences, the frequency of either tree clades, A, C and D was almost the same. Corals species may contain different clades of Symbiodinium depending on the region and on the tolerance characteristics of each clade. Thus, knowledge of zooxanthellae diversity associated with scleractinian can contribute to a better understanding of the sensitivity of corals to environmental conditions.Publishe