---

Aim and Background: Rachycentron Canadum is one of the most important commercial species in the Persian Gulf.  This study focuses on molecular investigation of mentioned species in order to find and introduce the genetic differentiations and also probable genotypes for monitoring and managing the genetic resources of populations in three major catch areas in the Persian Gulf and the Oman Sea.

Materials and methods: 120 individuals of this species were caught from the northern part of the Persian Gulf and Oman Sea. DNA extraction was performed from the dorsal part of the fin of 54 Individuals using Phenol-Chloroform method. Polymerase chain Reaction (PCR) was performed using a set of primers which designed based on NADH dehydrogenase (ND2) gene.

Results: The haplotype diversity from the populations of Bushehr 0. ± 0, Sistan Baluchestan 0. ± 0.3 and mean diversity was recorded 0. ± 0.015. Also haplotype diversity from the populations of Khuzestan and Hormozgan were 0. ± 0.04 and 0. ± 0.04 respectively and the mean diversity was recorded 0. ± 0.04. haplotype diversity from the populations of Khuzestan and Bushehr were 0. ± 0.04 and 0. ± 0 respectively and the mean diversity was recorded 0. ± 0.02.

Discussion: The study showed that some haplotypes of the populations belonging to Khuzestan were setting in one clade with common ancestor compared with the other population (Bushehr, Hormozgan and Sistan population) shown in another clade indicating that restricted genetic flow between Khuzestan and other studied areas. This study confirmed that several factors including barriers (mangrove forests) and marine currents can have an effect on the population diversity of this species in the Persian Gulf and Oman Sea.

---

Aim and Background: Chromosomal information of different species, in addition to improving classification and biological recognitions; it can be effective in breeding and genetic studies.

Material and Methods: Bred stocks were preyed from the east and west of Jask Harbour. Different growth stages were stained by Cholchicine and hypotonic KCL in different concentration and duration. Metaphase chromosome spreads were studied based on Campos-Ramos and Crash tissue methods and stained by Giemsa and distilled water.

Results: The testis tissue showed the best obtained spread. The number of diploid chromosomes (2n=86) was confirmed by the modal haploid chromosome number (n=43) in which 27 and 16 chromosome pairs were counted in meta/submetacentric and acro/telocentric, respectively.

Discussion: despite observed chromosome variations in karyotyping further Penaeidae family, the achieved diploid chromosome number of this study (2n= 86) exits within the range of diploid chromosome numbers previously reported for other species of shrimp (86 to 92).

Conclusion: treatments of testis tissue, staining by Giemsa 10% and crashing tissue method recognized as the best methods for karyotyping and chromosome spread analysis of Penaeidae family.

---

Aim and Background: Nanoparticles are widely used in medical, pharmaceutical and health sciences. The aim of this project was to evaluate the mesophilic bacteria isolated from the Gulf coast in the production of silver nanoparticles and investigate the antimicrobial effect of these nanoparticles on some pathogenic bacteria.
Material and methods: This descriptive and cross-sectional study was performed over a period of 8-month from April to November 2017. The isolates were purified from water and sediments samples of the coasts of Hormozgan Province - Iran, after that the purified isolates were cultivated in Zobell Marine Broth medium. The obtained supernatant of the medium was added to the silver nitrate (AgNO3) solution (0/001 M) with (1:5) ratio at the light condition in order to the reduction of AgNO3 to metallic silver. The synthesis of silver nanoparticles (AgNPs) was investigated by UV-Vis spectrophotometer, Transmission electron microscope(TEM), and Fourier transform infrared (FTIR) spectroscopy analysis. The antimicrobial activity of AgNPs was evaluated against 6 microbes.
Results: The results indicated that supernatants of all isolates are capable of producing silver nanoparticles. The surface plasmon resonance of AgNPs showed a maximum peak near 420 nm, which UV–vis spectra correspond to the absorbance of AgNPs. The results of TEM micrographs image of silver nanoparticles produced by dominant strain showed spherical shapes and size of 2/88 to 19 nm. The synthesized AgNPs showed the antimicrobial activity and inhibitory effects on the growth of tested microbes. 
Conclusion: The desired isolates have a potential ability to producing AgNPs, and to summarize, this is a low cost, ecofriendly, and quick method for the synthesis of AgNPs.