مجله علوم و فنون دریایی
سال یازدهم شماره 3 (پاییز 1391)

Nowadays, plant protein alternatives and increasing aquafeed efficiency are accentuated. In the present study the effects of injecting different dosages and chemical types of favonoid rutin on modulation of gilthead sea bream glycemia is studied in three consecutively distinct experiments. Fish were fed at 3% of their respective body weight twice a day with a diet containing 25% pre-gelatinized starch. Water temperature and photoperiod were adjusted near to 18ºC and 12L: 12D, respectively. Glycemia and hepatic glucose metabolism enzymes were measured. Results showed that 100 mg/kg BW of both chemical types of rutin significantly decreased glycemia (209.30±34.44 mg/dl and 120.18±9.84 for control and rutin treated groups in non-water soluble rutin, respectively, 125.50±6.54 and 99.83±6.46 for control and rutin treated groups in water soluble product, respectively) concomitant with increasing hepatic glucokinase activity (1.77±0.22 U/g protein and 6.13±1.20 for control and rutin treated groups in non-water soluble rutin, respectively, 20.19±1.51 and 25.77±1.61 for control and rutin treated groups in water soluble product, respectively). However, the time required for rutin to show its hypoglycemic effect is shorter for non-water soluble product (6 hrs after rutin injection) than water soluble one (9 hrs after rutin injection). Results implied that it is possible to manipulate the carbohydrate metabolic machinery of gilthead sea bream using hypoglycemic phytogenics (rutin) similar to laboratory rodent hyperglaycemia models.

Kilka as an economic fish, has an important role in the food chain of the Caspian Sea. This study carried out during 2006-07 for estimation of maximum sustainable yield in the southern Caspian Sea. Sampling on the southern coast of the Caspian Sea was carried out from October 2006 to September 2007 in Bandar Anzali and Babolsar. During the review period, 1533 fish were measured and weighed, aging was done by using sagitta otoliths.The results showed that the mean length of common kilka was 102.4±9.7 mm ranged from 56 to 144 mm. Mean age was 3.6 years and over 73 percent of the samples were composed of third and fourth year classes. Growth coefficient (K) using the Ford – Walford plot and total mortality coefficient (Z) were estimated 0.321 and 1.280 per year, respectively. In the present study, the common kilka stock in the South of Caspian Sea was estimated about 58.75 thousand tons by using cohort analysis. The maximum Sustainable yield (MSY) was finally obtained 25,322 tons by Cadima equation. The first priority as a management measure of common kilka stock is supportive policies.

This study was carried out to determine the influence of highly unsaturated fatty acid (EPA, DHA) enriched Artemianauplii on growth and survival of postlarvae of Litopeneausvannamei(PL-1 to PL-15) in Persian Gulf and Oman sea ecology research center of Bandar Abbas. A complete randomized design with 5 treatments and 3 replicates using15 tanks containing 20 liters water each was chosen. The Artemianaupliiwere enriched with (0 to 4%) cod liver oil (treatments A to E) and the larvae were fed 6 times per day at 4 hours intervals. The postlarvae of treatment D which fed with Artemianauplii, 3% of enrichment significantly increased compared to other treatments (p<0.05).The highest survival rate regarding treatment E postlarvae which fed with Artemianauplii, 4% enrichment However with treatment D (3%) and C (2%) no significant difference (p>0.05) was found. The postlarvae of treatment control (A) which was fed with Artemianauplii that it was not enriched, had the lowest growth and survival rate.The present study demonstrated that the highly unsaturated fatty acid enriched Artemianaupliihas positive effect on enhancement of growth performance and survival rate of white leg shrimp postlarvae.

Changes and Countries development and need to Scientific, Cultural and Industrial commutation at Global level requires accessibility to maps and spatial information from the entire world. Achieving to this aim requires equalization of horizontal and vertical datum of all countries. Nowadays with developments in technology and after that increasing in precision of vertical datums is one of the basic arguments and there have been efforts to find vertical datum and relations between them. One of the problems that exist in using absolute heights is difference between M.S.L and Geoid.The theoretical basis the absolute heights is Geoid but in practice M.S.L is used as absolute vertical datums. Therefore difference between M.S.L and Geoid is called sea surface topography. In this research one of the all, we have carried out modeling mean sea level using T/P and Jason-1 satellites altimetry data on Persian Gulf and Oman sea, Accordingly Due to the significance of sea level topography in oceanographic studies a new model proposed using the combined satellites altimetry data and the EGM08 global Geoid model in order to determine and equalize the current height datum for Persian Gulf and Oman sea. Therefore, difference between M.S.L derived from T/P and Jason-1 Satellites altimetry data and EGM08 global Geoid model was assessed -0.9 and 1.1 meter respectively.

Chronic stresses can influence the behavioral and physiological activities of animals and can lead to reduction of resistance against disease and decrease in growth rate and production.Artemianauplii enriched with essential nutrients particularly fatty acids have been used to promote growth, survival and resistance of different species of aquatic animals to various environmental stresses as well as infectious diseases. In this study we investigated the resistance to environmental stress (temperature, salinity and hypoxi) in larvae of rainbow trout fed Artemianauplii enriched with vegetable oils. The experiment was carried out in 6 triplicate treatments for a period of 10 days. The feeding treatments included: 1) commercial starter feed for trout (Control) 2) Artemianauplii enriched with fish oil, 3) Artemianauplii enriched with sunflower oil, 4) Artemianauplii enriched with canola oil, 5) Artemianauplii enriched with soybean oil and 6) newly hatched nauplli of Artemia. The results showed significant differences in tolerance of fish larvae to high temperature (20 and 25°C), hypoxia stress (5 ppm) and salinity stress (10, 15 and 20 mg.l-1) among different groups. Highest survival to all experimental stresses (except in one case) was observed in larvae fed Artemianauplii enriched with canola oil compared to those fed control diet (p<0.05), but in most cases not significant with larvae fed Artemianauplii enriched with fish oil.

This research aimed to study the process of Spatial and Temporalchanges of sea star(Astropecten hemprichi) and sea urchin(Diadema setosum) in the coasts of Chabahar Gulf in the Oman Sea, IR. during November 2008 to September 2009. The area of study was at the farthest end of south east of Iran in province of Sistan and Balouchestan. Sampling was done bimonthly during low tide from 5 stations, using 1m×1m quadrating randomly. 1885 samples of Echinodermata were collected and studied. Results showed that 32 of them(1.6%) belong to A.hemprichi species and 28(1.4%) samples belong to D. setosum species. The samples then were counted and identified. Then the samples’ abundance, distribution and stability were investigated. The results show that the maximum abundance of A. hemprichi was occurred in September 2009 (1/92±0/76ind.m-2) and The maximum value for D. setosum was shown in November 2008 (3ind.m-2). Investigation of distribution and stability indicators may reveal that A. hemprichi and D. setosum were dispersed more randomly and they may be considered as the rare species.

The optomotor response is one of the methods used for measuring zebrafish behavior towards moving objects. The present research has been carried out on zebrafish reaction to moving objects. In the experiment, newly fish matured of both sexes were used. To study the optical power of zebrafish an appropriate apparatus was designed. Experiments were performed with different widths of stripes in black, white (1, 2, 7 cm), with width stripes of 1 cm in red - gray, green - gray at different velocities of 2, 3, 4, 7, 10, 15 rpm.Results of 2-way ANOVA showed significant differences between the various widths, velocities (P<0.05). Evaluation of results showed that at different widths, fish showed the most optomotor response at a velocity of 10 rpm (0.65±0.13), the lowest response to velocity was shown at 2 rpm (-0.07±0.22). Furthermore, the best visibility was observed with 1 cm width (0.70±0.13) (P<0.05).Experiment on color vision also showed that at different velocities, various colored strips, there is no significant difference (P>0.05). Nevertheless, the fish demonstrated the most optomotor response to green - gray color (0.10±0.13), a velocity of 10 rpm (0.41±0.13).