JOURNAL OF MARINE SCIENCES AND TECHNOLOGY
Year:2006 | Volume:5 | Issue:1-2|Papers Count:12

Effect of triploidy induction on some hematological indices of premature all-female diploid and triploid rainbow trout, Oncorhynchus mykiss, was investigated in winter season. All female diploids were obtained by insemination of spermatozoa from sex reversed females (Neomale) with oocyte of normal females. All-female triploids were also produced similarly and by using heat shock of 26.5oC for 20 minutes to eggs 20 minutes post fertilization. Blood samples were taken from fish caudal vein using 5% EDTA as anticoagulant. Hematological data indicated that in all female triploid, mean number of total erythrocytes, hematocrite value and hemoglobin content were significantly lower (p<0.01) than all female diploids while mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were significantly higher (p<0.05) than all-female diploids. Furthermore, the mean number of total leukocytes was significantly lower in triploids (p<0.01), but there was no significant difference in differential counts between lymphocyte and neutrophile percentage in diploids and triploids (p>0.05). Although erythrocyte hematological indices were lower in triploids, but increased mean corpuscular volume and consequently higher mean hemoglobin concentrations have set the equivalency between hematological indices in all-female triploids.

Attempts were made to prepare two kinds of shrimp salads (cold salad and macaroni salad) from Penaeus indicus. Sensory evaluation of the shrimp salads gave encouraging results. The shrimp salad made from macaroni with 400gr of the shrimp meat was adjudged best on the basis of its scoring for appearance, palatability and overall acceptability, respectively 6.63±0.2, 5.38±0.3 and 5.88±0.2 between treatments. The average cost of shrimp salad was estimated to be 15 thousand Rails per kg. With a sale price of 22 thousand Rails per kg and sale of 50 kg per day of the shrimp salad (26 days in a month), the average monthly income of a fish salad-preparing unit (of two persons) comes to 910 thousand Rails.

Mercury accumulation and its effects on kidney and gill of golden grey mullet, Lize aurata, fry were investigated. The fry (1.5-2g) were caught from Iranian coasts of the Caspian Sea (Noor) on April 2005. They were held in a 4001 tank, with continuously aerated Caspian Sea water for at least 4 days prior to experiment. Each experiment began with the transfer of 20 fishes from the stock tank to the experimental aquariums (50L) contain, 0, 50, 100, 350 ppb of HCl2. No mortality was observed on 0, 50 and 100 ppb exposed groups following 96 hours. Hg concentrations were 549.5, 1893.1 and 3364.7 ppb in the gills of control, 50 and 100 ppb group, respectively. Mass mortality observed in 350 ppb exposed group following 2 hours and Hg concentration in the gills was 15300.2 ppb. In all Mercury treated groups, lifting epithelial cells from lamellae, lifting and rupture basal membranes of epithlia cells, hypertrophy and hyperplasia of gills cells were observed. Fishes exposed to 350 ppb also showed gills cells neerosis. Glomerulu’s capillary dilation and vacuolation of the proximal tubule cells of kidney were observed in the all Mercury treated groups.

Contribution of the production factors, production costs during the years 2000-2004, and means for increasing the productivity and profitability of sturgeon hatcheries in Iran were investigated by compiling and analyzing the available information, including the documents available in enhancement offices. We designed a questionnaire covering economic and ecological aspects of the activity and distributed it to an aquaculture related expert team. Different sections of the Iranian Fisheries Organization, specially, accounting, budgeting and stock. The results showed the cost of labour and salary comprised 38-56% of expenditures whereas costs of feeding and fertilizer were found to be 4-14%. The maintenance cost was assessed as 4-8%, fertilized eggs cost was 6-35% and depreciation cost was 10-12% of total expenditures. The production cost of a single sturgeon fingerling in Iran was 937-2028 Rls over the 2000-2004. The cost of labour and salary had a large share in total expenditures, somewhat caused by the centers not being active for six months each year. Engaging the labour force with other activities such as cultivation of indigenous and exotic surgeon brooders might be expected to reduce the total costs. With increase in price of caviar in recent years, the price of fertilized eggs has also increased to 35% of total expenditures. It seems cultured sturgeon brooders might fill the gap left by wild brooders inaccessibility in coming years of wild sturgeon.

Growth and biomass of Nannochloropsis oculata in different culture media including F/2 (Control), Conway, Miguels, Sato and TMRL with density 5×106 cells ml-1 in six days were compared. The experiments were carried out at temperature and light intensity of 25±2oC and 3500±350 lux, respectively. The experiments conducted in 5 replicates and each treatment sampled 3 times. Results showed that Conway and TMRL media with 44.4 and 1.6, respectively, had maximum and minimum percent of cells abundancy at the end of sixth day. Mean increase in population density in F/2 medium was 22×106±9.6×106 cells ml-1. Conway and TMRL media with 18×106±59×106 and 0.5×106±2.1×106 ml-1, respectively, had maximum and minimum cell densities. Absorption and turbidity rates in F/2 medium (control) was 0.8±0.15 and 370 ± 62 FTU, respectively Conway and TMRL media with 1.1±0.05 and 0.3±0.2, 457±29 and 134±36FTU, respectively, had maximum and minimum values. There was no significant difference (P<0.05, S.L=0.01) in the cell density between Sato and TMRL media. This study indicated that Conway medium had the potential to be used as an effective medium for the culture of Nannochloropsis oculata microalga.

Determination of suitable size for releasing of the Caspian trout juveniles into the Caspian Sea to enhance its fishery return was investigated through Na+, Mg2+, Ca2+ and Cl- regulation ability of 5, 10, 15 and 20 grams juveniles in freshwater (control), the Caspian Sea water and 7 PPT water media. Blood samples were drawn at 0, 3, 6, 12, 24, 72, 168 and 240 hrs, using heparin tubes, and centrifuged to extract the plasma. Ca2+, Mg2+ and Cl- ions in the plasma were measured using RA-1000 instrument, while Na+ was estimated using Flame Photometer. The ionic fluctuations within 10 days of experimental period indicated that fish of all size groups could regulate their ions in water of 7 PPT salinity while in the Caspian Sea water the 5gram group failed to do so.

The artificial propagation bionormatives of Acipenser nudiventris was determined aiming mass propagation and preventing the extinction of this rare species. Results from 9 female and 5 male broodstocks showed an average absolute fecundity of 414000 and the number of oocytes per gram as 68.4. In addition, the oocyte average weight and diameter were 12.97 mg and 3.02 mm, respectively. In order to induce ovulation and spermiation, the extract of aceton-dried sturgeon pituitary was used amounting 70 and 50 mg at 16.1 C for the female and male, respectively. Also, spermatozoid activity and density were determined. Duration of maturity in the broodstocks was 27:30 to 36:40 hours. The average fertilization and mortality rates during incubation period were 85.38 and 61.75 percent, respectively. The duration of reaching 4 and 16 blastula division was also determined. This study showed that with getting more knowledge about bionormatives of this rare species, we could plan artificial propagation procedure with good efficiency.

In this research, using Hanson and Short method, the various reactions of Mazandaran province shoreline against wind-driven waves and the beach status were determined. First, the kind of hydrodynamic forces governing the beaches were investigated and these beaches recognized as wave-dominated. Then, eight stations along the entire shoreline were selected and waves and sediments characteristics in various depths were investigated employing field measurements, laboratory and calculated data. In this way, the dimensionless fall velocity parameter was calculated in each station and the beach status and its variations with time were calculated. Finally, the obtained data were transferred into the Arc GIS software and the waves dynamic and the mechanism of erosion and accretion in the regarded zone were investigated.The results showed that the beach status of the central and eastern coasts of Mazandaran province (Neca, Farahabad, Larim, Naftchal, Mazandaran University, Babolsar, Noor stations) is dissipative, and the quantity of dissipation decreases from east to west, discontinuously. Moreover, the beach status of the western part of this province (Nashtarood station) is intermediate.

Naphthalene degradation bacteria from Noushahr and Amirabad waters of the Caspian Sea were isolated by initially culturing them in minimal basal medium supplemented with naphthalene and trace elements and incubating at 30 C for 24-72h. For evaluation of naphthalene degradation, the three isolated bacteria consisting of Bacillus sp, Pseudomonas sp and Vibrio sp were selected and two concentrations of 30 and 40 mM of naphthalene in minimal basal medium (MBM) and times of zero to 312 hour for examination of growth kinetic were used. The results showed that concentration of 30mM and 40mM of naphthalene after 312h were decreased to 9.45 (68.8%) and 30.45 (91.42%) for Bacillus, 7.56 (74.8%) and 9.45(76.37%) for Pseudomonas,10.45 (64.86%) and 19.39 (74.20%) for Vibrio, respectively.