Cryopreservation of carp spermatozoa by different extenders

Production and storage of the best gametes are practices undertaken by fishery managers and researchers to improve fish reproduction technology and obtain the best spawners. The male spawners of carp (Cyprinus carpio) were chosen from two warm-water fish hatcheries near Rasht, Guilan Province. For the study, duration of motility of sperms, sperm density and fertilization rate were considered. The best samples were chosen for mropreservation with four different extenders and were checked by fertilization tests after seven days of preservation in liquid nitrogen. Results showed that by 1:1 dilution rate, the Alsever solution had the best results. The fertilization rate, production of eyed ego and larvae by this extender in a multistage cooling experiment were 45r, 47.81" and 22.63 respectively

Molecular population genetic of Persian sturgeon (Acipenser persicus) and stellate sturgeon (Acipenser stellatus) using microsatellite markers

The fishery stocks of most commercial aquatic stocks in the world have shown declining trends in the past two decades. Several factors have been responsible for the decline of stocks the most important of which over fishing and over-exploitation, pollution, loss of natural habitats and natural spawning grounds, construction of dams and bridges across the important rivers which restrict the migratory routes of spawners, decrease in natural reproduction and rehabilitation of stocks through artificial breeding programs. Over-exploitation of stocks and pollution directly affect decreasing stocks in an ecosystem. Not differentiating between different populations and stocks of a species found distributed in an aquatic ecosystem is considered one of the main factors which causes the depletion of stocks in most ecosystems in the world. In most cases this is because genetic variations in aquatic stocks in the wild are not taken into consideration. Six species of sturgeons are found living in the Caspian Sea and its drainage basin which produce more than 85-90% of the world caviar. The Persian sturgeon (Acipenser persicus) and the stellate sturgeon (Acipenser stellatus) are the main sturgeon species of the Caspian Sea. The Persian sturgeon is mainly found in the south Caspian Sea while the stellate sturgeon stocks are considered shared stocks by the five Caspian littoral states. Due to over fishing in the past two decades the legal catch figures for sturgeon stocks in the Caspian Sea dropped from 28500 tons in 1985 to less than 1500 tons in 2004. Similarly caviar production also dropped from 3000 tons to 110 tons in 2005. With regard to the severe reduction in sturgeon stocks it is necessary to take essential steps before these valuable species are totally wiped out. The fisheries management of the five Caspian littoral states should focus their efforts on identifying the different populations and stocks found in the Caspian Sea. Concerted measures should be taken to study the distribution and biomass of the different populations in order to develop a scientific solution for the sustainable use of these endangered species and to secure the long term conservation of sturgeon stocks. The aim of present study was to evaluate the genetic structure of the population of two species Acipenser persicus and Acipenser stellatus and to develop molecular markers to identify and differentiate different populations of these two species

Conservation and restoration of Caspian salmon (Salmo trutta caspius) stocks in the southern Caspian

The project is funded by the CASPECO Project which is the Third Phase of the GEF supported project in the Caspian Sea region titled “The Caspian Sea: Restoring Depleted Fisheries and Consolidation of a Permanent Regional Environmental Governance Framework”, and implemented by the Iranian Fisheries Research Organization (IFRO) in partnership with four Coastal Research Centers affiliated to IFRO, Coldwater Fishes Research Centre (CFRC).The project's objective is to improve the conservation and restoration of Caspian Salmon (Salmo trutta caspius) stocks. In accordance with IUCN criteria Caspian Salmon is placed in the red list of endangered fish. In the recent decades the destruction of habitats for juveniles, reduction of genetic diversity and fish immune system were main causes of the Caspian salmon decline. Numbers of public meetings were held with participation of fishing communities’ representatives, experts, relevant local authorities and experts of the IFRO and Iranian Fisheries Organization (IFO), Iran Environment Protection Organization (IEPO), Water Resource Management (Ministry of Energy) and University senior professors, in order to create interaction and understanding of the project objectives. Educational awareness and extension program were conducted with the involvement of fisheries communities, private sector and NGO associations. The results of the project suggests that cross-sectoral coordination for sustainable fisheries can be achieved through building partnerships and enhancing communication between the environment, private, fisheries sectors and academia. Cross-sectoral cooperation through this project improved public awareness on growing risks facing Caspian Salmon from different sources including local sources (illegal fishing and over-fishing, urban wastewater, environment destruction, industrial pollutants, pollution of air and water resources), new emerging and invasive organisms, climate change, implications of the Caspian salmon population decline on economic and social affairs of the people who depend on them for their livelihood and food security and their role in fish stock protection. The project, through its capacity building, extension and educational programs and efforts to link science to management, could translate scientific findings into an action agenda for managers and policy makers that can bring an improvement in the future of the Caspian Sea salmon stock

Study on genetic structure of Caspian Sea sturgeons in the stock assessment of sturgeon in Iranian coastline of the south Caspian Sea

The population genetic structure of the Persian sturgeon (Acipenser persicus) in the 2, 3, 4 fisheries regions and Sefidrud River was investigated based on the DNA sequencing method during 2010–2013 sturgeon stock assessment in the south Caspian Sea . DNA samples were extracted using ammonium acetate, the quantity of DNA was measured at 260 and 280 nm using spectrophotometry by Nanodrop (ND 1000 model), and the quality was checked by 1% agarose gel electrophoresis. Two sets of mitochondrial gene (D-loop and cytochrom b) after synthesis were used for polymerase chain reaction (PCR). A Neighbor-Joining (NJ) tree was constructed for all haplotypes according to Kimura 2-parameter model using Mega Version 4.0.1, number of haplotypes, haplotype diversity (Hd) and nucleotide diversity and their corresponding variances, genetic divergence overall and between paired populations (Fst) by 10,000 permutations and exact test, the gamma distribution shape parameter for the rate heterogeneity among sites and nucleotide sequence, the historical demographic pattern of A.persicus using neutrality tests and mismatch distribution analysis (D test of Tajima and Fs test of Fu), also the concordance of the observed with the expected distribution under the sudden population model using the Harpending, s raggedness index (Hri) were analysed. All calculations were conducted using ARLEQUIN version 3.11 and DnaSP 4.0. The aligned mtDNA sequences of D-loop and cytochrom b genes were consisted of 500 and 700 base pairs (bp) respectively. 13 and 4 haplotypes were defined, the average haplotype diversity were 0.961 and 0.419, average nucleotide diversity were 0.038 and 0.002, The gamma distribution shape parameter were 0.19 and 0.20 indicating moderate mutation rate heterogeneity among sites in A.persicus. The lowest value of Fst for D-loop gene was calculated between Sefidrud and four fisheries region (-0.002) and the Fst values observed for cytochrom b gene was 0.04 with Nm=5.37 and not statistically significant. The exact test of population differentiation (non-differentiation exact P values) showed significant differences between Sefidrud and other areas (P ≤0.05) for D-loop gene and for cytochrom b gene was nonsignificant (P ≥0.05). The mismatch analysis produced a unimodal distribution of pairwise differences for both genes which was consistent with the sudden population expansion model. Tajima’s D and Fu’s Fs statistics were significantly negative (D= -0.84 and - 0.99, P>0.01; Fs=-0.220 and -0.079, >0.01). ARLEQUIN calculated the value of t as 13.65 and the time since population expansion was estimated to be approximately 1501 years before present based on the mutation rates for the control region and this value for cytochrom b gene t= 0.98 which population expansion time was 7.84 years before present. The results of this study based on D-loop gene showed that population of A.persicus in the Sefidrud River is differ from other studied areas. Therefore fisheries managements of this unique and valuable stock for restocking and conservation of gene pools is strongly recommended