JOURNAL OF BIOLOGY SCIENCE
Year:2009 | Volume:3 | Issue:3 (SERIES NO. 10)|Papers Count:11

One of the usages of sperm cryopreservation is help to protect of endangered species. The life of spermatozoa is very short time in natural conditions and we can not conserve it for long time. While by semen freezing and use of suitable extenders and cryoprotectants we can conserve it in liquid nitrogen for several years and we can use stored sperms in essential times. In this research milt obtained from five Persian sturgeon (Acipenser persicus) were diluted using Tris-sacharose-egg yolk (23.4 mM Tris, 1.8mM sacharose, 20% egg yolk) as extender and methanol as cryoprotectant in four concentration (8, 10, 12, and 15%). The suspension was poured in to 0.5 ml straws and frozen in-196°C liquid nitrogen vapour in a three storage programe. Then straws were transferred to liquid nitrogen tank. The sperm samples were thawed in a 40°C water bath for 25s and the sperm motility rate and it's motility time were observed using microscope. There was not statistical significant difference between selected concentration (P>0.05) but the highest post-thaw motility rate and motility time (7.00±2.15% and 102.30±39.14s respectively) was found using 8% methanol after preservation in liquid nitrogen about 7 days while the lowest post-thaw motility rate and motility time (1.25±0.56% and 23.00±9.60s respectively) was found using 8% methanol after preservation in liquid nitrogen about 72 days. Results indicate that the increase in sperm preservation in liquid nitrogen has a negative effect on sperm quality and also increase in concentration of methanol from 8% to 15% does not change the percentage of motile cells and motility time on sperm cryopreservation of Persian sturgeon. In This project methanol as a cryoprotectant had not successful efficiency on sperm cryopresevation of Persian sturgeon.

Lactic Acid Bacteria (LAB) are part of fish intestinal microflora. The aim of this study was to characterize and identify Lactic Acid Bacteria (LAB) isolated from the intestines of Persian Sturgeon. Twenty five healthy Persian Sturgeons were randomly selected and sampling were done aseptically from the intestine. After making series dilution, they were cultured on MRS agar plates. The plates were incubated anaerobically at 37°C for 24-72 hr. All bacterial species that were grown on this medium were bacilli or cocci form, Grampositive, Catalase-negative and non motile. The tests used for identification of the bacterial strains were acid production from carbohydrates, growth at different temperatures, growth at different pH, growth in media with 5.6% NaCl, production of gas from glucose and production of NH3 from argentine. The average number of bacterial cells in intestine of fishes were 2.41 (Log cfu/gr). The Entrococcus spp. was the dominant bacteria cultured from the gut of Persian Sturgeon.

Juniperus excelsa is one of the momentous species of Iran whose hn cludes 500 thousands hectares. The genetic diversity was studied in this research. Sampling was done in khorasan Razavi province. According to results peroxidase and amylase of the juniper seeds in the aforementioned two habitats through polyaccrylamide gel betoken the fact that peroxidase activities have better results owing to their numerous enzyme bands with regard to amylase. The number of the peroxidase cathodic bands of Hezarmasjed line habitat can yield a positive affect upon the procreation power and the withstanding capabilities of juniper saplings in this habitat.

Shirood River is in the North of Mazandaran province between Ramsar and Tonekabon. The length of this river is 30 km and its average Debi is 7.2 m3/s. According to its unique ecological and biological characteristics, every year hundreds of Caspian Sea Brood stock Kutum ( Rutilus frisii kutum) emigrate to this river for reproduction, so that it has an attend able role in recovery of Kutum stocks . For this reason 45 Kutum was surveyed during the reproduction migration season 1381-2 (since March 2006 till May 2007). So after fishing and carrying to the laboratory different fish organs such as skin, gill, eye and digestive organ have been studied. According to the researches 7 species of parasites by the name of Paradiplozoon chazarkum, Dactlogyrus sp. (monogenea), Diplostomum spathaceum, Asymphylodora macracebulum, Asymphylodora kubanicum (Digenea), Raphidascaris acus (Nematoda) and Aspidogaster limcoides (Aspidogastereae) were recognized. Between these 7 parasites, Dactylogyrus sp., had the highest Prevalence (93/3 %), mean intensity (35) and parasite number range (1-150). While the lowest prevalence was related to D.spathaceum, A. limacoides, A. kubanicum(2/2 %), the lowest mean intensity were referred to A. limaciodes and A. macracetabulum (1), the lowest number range was related to A.limacoides(1), also according to this research parasitical pollution of Kutum had age and sexual differences.

This study carried out on 11 wild male brood fish of Persian Sturgeon in 1388 and in the Shahid Beheshti Sturgeon rearing and Propagation Center & International Sturgeon Research Institute (Rasht). In this study, each brood fish was received hormonal injection twice in few days interval (3-7days) and then sperm samples were stripped. Sperm from 6 brood fish used for second time were collected and some spermatology parameters, incubation rate and larval size were assessed during each sperm stripping. The results showed that the mean rate of sperm motility in first and second sperm stripping were 78.5±5.43% and 50/0±20/25% respectively. The mean duration of sperm motility in first &second stripping were 315/83±162/16 and 212.5±110.53 seconds respectively. Also the mean sperm density in first and second sperm stripping were 2.1±1.3×109 and 0.55±0.34×109/ ml respectively with spermatocrit level at 9.33%±3.32 and 3.42%±3.35. Sperm samples pH also showed that mean sperm pH were 8.41±0.53 & 8.05±0.33 in first & second stripping respectively. Mean Incubation rate in first stripping was 62.5±21.07 and mean incubation rate in second stripping was 34.83±21.92.The mean larval size in Incubation stage in first stripping was 12.18±0.33 mm and 11.22±0.38 mm for second stripping. The mean larval size in the beginning of active feeding stage in first stripping was 20/68±0/53mm and for second stripping was 19/52 ± 0/19. Calculations showed that there have been significant different among incubation rate and size of the larvae in Incubation stage and beginning of active feeding stage between two stages of sperm stripping (p<0.05).

The freshwater rotifer Brachionus calyciflorus is an indicator of pollution and is used in feeding fish larvae. This species is found in most freshwater bodies in the world particularly in sturgeon rearing ponds. The effects of different temperatures (25 to 37°C) was studied on pure cultures of rotifers collected from pond 11 from the Shahid Beheshti sturgeon hatchery. The rotifers were maintained at stocking density of 50 ind/ml for a period of 7 months to acclimatize them to laboratory conditions. Four different ranges of temperature (Group 1=25 to 28ºC, Group 2=28 to 31°C, Group 3=31 to 34 °C and Group 4=34 to 37°C) were studied. Three replicates were used for each trial. Experiments were carried out in test tubes placed in water baths. The maximum volume of each experimental group was 20 ml and the pH of the medium was 7.6. The density of rotifers in each test tube was 1 ind/ml. Rotifers were fed the algae Chlorella vulgaris at a rate of 8´105 cells/ml for a period of 9 days. Milt aeration was provided and test tubes were exposed to 1000 lux light intensity. Rotifers were counted everyday. The relation between temperature and mean density in rotifer populations and time required to reach maximum density was studied using Tukey test and one way ANOVA. Results obtained indicate no significant differences in density of rotifers at different temperatures studied (P>0.05). However significant correlation were detected between maximum density and increase in temperature (P<0.05) wherein during the study period rotifer density in Group 1 reached 410±20 ind/ml on the day seven of the experiment, whereas Group 3 showed 300±50 (ind/ml), respectively on day tow of the experiment. Final results experiment period indicating highest and lowest growth rate showed respectively in Group 4 reched (1.44±0.05) and Group 1 reched (0.45±0/08).

Forest roads have a crucial role in forest management, maintenance and regeneration in mountainous forest. In this study, GIS was used for producing essential maps to improve the accuracy and quality of forest road planning based on soil stability in the Shafaroud catchment (Northern Iran), which covers approximately 1742 ha. Soil stability map was prepared through merging soil texture and bed rock maps in 5 classes: stable, semi stable, medium stable, semi unstable and unstable. With regards to the main factors of road planning and their variety value, questionnaires about the opinion of specialist were collected. Following that slope, aspect, altitude, volume, tree type and soil stability maps were merged to produce road crossing capability map in three classes with high, medium and low ability. Using PEEGER, a new road network based on soil stability was planned, and then compared it with existing road. Results show that there was significant difference between their density, stability and technical structure. Hence, new planned road was better than existing road.

Group A streptococci have been traditionally identified by Lancefield method, fluorescent antibody technique and susceptibility to bacitracin. In this study, group A streptococci were identified by L- pyrrolidonyl-b- naphtylamide(PYR) hydrolysis test which both PYR substrate and reagent were made in our laboratory. A total of 90 b-hemolytic streptococci were isolated from September 2009 to February 2010 from Kerman and Tehran hospitals. Isolates were serogrouped by slide agglutination test with specific antisera. Finally, by considering the serology as the gold standard, sensitivity, specificity, positive predictive value (ppv) and negative predictive value (npv) were calculated. Among 90 isolates were grouped by antisera, 50 isolates were group A, 30 group B, 9 group C and one group G. The sensitivity of PYR and bacutracin tests were equal (98.9%), but the bacitracin test had a lower specificity (87.5%) than the PYR test (100%). All bacitracin tests were performed on subcultures of isolates from the primary plate whereas PYR testing was performed on colonies from the primary plate. This shortened the turnaround time for PYR compared with bacitracin by at least 24 hours. This study showed that PYR test is a rapid and simple alternative to the standard tests and save the time required for subcultures and antigen extractions. The results are available in 10 to 15 minutes. The regent can be prepared in all laboratories.