JOURNAL OF MARINE BIOLOGY
Year:2010 | Volume:2 | Issue:7|Papers Count:8

The present study was carried out during autumn and winter 2009- 2010 in the Mongoft area (Bushehr waters). In both seasons two fishing methods, trap and hand-lining were used. The samples were carried to the laboratory. The samples were identified and their quantity and weights (gr) were recorded. Some biological indices such as diversity and evenness and species richness were calculated by using the Shannon and Simpson indices, Evenness and Margalef and Menhinich indices. PRIMER (v5) software was used for data analyses. In both seasons, the number of caught species at the artificial reef was more than those of control site. In autumn 62 specimens with trap and 13 specimens with hand-line were caught, where in control site 22 specimen with pot and 13 specimen with hand-line were caught. In winter, 15 and 36 specimens were caught with trap and hand line respectively , while in control site 13 specimens with trap and 9 specimens with hand-line were caught. In autumn, catch per unit effort (CPUE) (gr/t/d for traps and gr/h/h for hand-lining) at the artificial reef (with trap 46(gr/t/d) and with hand-line 599(gr/h/h)) was higher than the control site (with trap 14(gr/t/d) and with hand-line 442(gr/h/h)). In winter, CPUE (gr/t/d) at the artificial reef (45(gr/t/d)) was higher than the control site (35(gr/t/d)), but CPUE (gr/h/h) in control site (114(gr/h/h)) was greater than the artificial reef that (35(gr/h/h). Biological indices of diversity, evenness and species richness at the artificial reef in autumn showed better results in comparison with the control site, but at the winter under catching with trap ,artificial reef had better condition in comparison with control site, but about the amount of catch by hand-line, the similar condition were observed in both regions. Therefore, in autumn the artificial reef with respect to the abundance, diversity, composition and catch was in a better condition with respect to the control site, but the results were not significantly different (P³0.05). In winter in both regions, in spite of having the differences, the same results have been observed.

In recent years, use of medical herbal as immune-stimulants and immune system booster in diets of fish was increased. In order to study the effect of milk thistle ectract (Silybum mariamun),silymarin, on non-specific immune system of rainbow trout (Oncorhynchus mykiss), fish were fed on diets containing 0,100,400 and 800 of medical supplementary silymarin mgr/kg diet for 28 days .The levels of following parameters of plasma, immunoglobulin IgM, total complement, lysozyme and peroxidase were measured . There was no significant difference between levels of immunoglobulin IgM, total complement and lysozyme in plasma of fish fed under diets of medical supplementary silymarin compared with control group (p>0.05), but the levels of peroxidase in the later mentioned groups fish fed under diets of silymarin were significantly higher than control group(p<0.05). The result indicated that milk thistle- extract, silymarin, caused positive effects on the immune system of rainbow trout.

This study was conducted in order to characterize the effects of different diets on survival and some growth factors of Acipenser persicus in the International Sturgeon Research Institute in 2010. Thirty tanks were prepared and filled with water. Also, 60 larvae were selected randomly and their weight and length were measured and then were transferred to mentioned tanks. Ten diets containing different amounts of usual concentrated feed, Daphnia powder and Nereis powder were prepared as experimental diets. Five days after active feeding, in order to adaptation with larvae digestive system, feeding with special diets was continued. Ten days after active feeding, larvae were fed 30% of their wet weight with experimental diets for 35 days. Physico-chemical parameters of water were measured carefully twice a day. At the end of experiment, the weight and the length of larvae were measured and survival rate and some growth factors such as FCR, SGR, BWI and GR were calculated. The results showed that larvae fed diet 3 (100% Nereis powder) and diet 4 (50% Daphnia powder and 50% Nereis powder) had the highest survival rate, SGR, BWI and GR compared to other treatments (p<0.05). On the other hand, these two treatments (3 and 4) along with treatments 1 and 5 have the lowest FCR compared to other treatments (p<0.05). The lowest survival rate, SGR, BWI and GR was observed in fish fed diets containing 100% concentrated feed (p<0.05). The results of the present study showed that using Nereis powder lonely or in combination with Daphnia powder comparing to concentrated feed may have beneficial effects on survival and growth of Acipenser persicus.

In this cytological study under following 3 methods, spread of blood cells, bath of cholchesin and injection of cholchesin, the karyotype of blue carb were prepared. It was found that the best method was injection of cholchesin and the best tissues for cellular spread were mature testis and gill in male and female respectively. Haploid number of chromosomes was determined to be n=51 by coding them in testis cells. Modal diploid number was 2n=102 which was counted the chromosomes of cell's tissue of female's gill. Tentative karyotype of the blue crab, contained, 4 pairs of metacentric, 24 pairs of sub metacentric and 23 pairs of telocentric chromosomes.

Usage of Silver Nanoparticles progressingly expands in various industries. In order to study the probable usage of these materials in aquaculture, the toxicity effects(LD50) and Maximum Allowable Concentration (MAC) of Silver nanoparticles in the following four fish species, Ctenopharyngodon idella (cultured fish), Barbus grypus (wild fish), Cichlasoma severums and Astronorus ocellatus (ornamental fish), were calculated. The toxicity was calculated based on static OECD standard method. Each species were challenged with 8 serial dilutions of Nanoparticles and daily mortality was recorded for 96 hours. LC50 and MAC calculated using Probit software. Results showed that LC50 96h of Nanosilver in Ctenopharyngodon idella, Barbus grypus, Cichlasoma severums and Astronorus ocellatus were 0.12, 0.086, 6.85 and 7.89 mg/ml respectively, versus The MAC of Nanosilver in these species were 0.012, 0.009, 0.69 and 0.79 mg/ml. There was Significant difference among toxicity rate of silver nanoparticles among fish species (P<0.05). Although no significant differences were seen between Ctenopharyngodon idella, Barbus grypus as well as Cichlasoma severums and Astronorus ocellatus in Nanosilver toxicity, significant difference observed between these groups (P<0.05). According to the results of this study it can be conducted that reared and wild fish were more susceptible to Silver Nanoparticles than ornamental fish.

In this study, 251Barbus lacerta were caught from Keseliyan river during August 2008 - July 2009. In order to determine morphological diversity of this species, 26 morphometric characteristics and 10 meristic characteristics were investigated. Results were analyzed with SPSS 16 software and by T-test and PCA. According to the results, the average of coefficient changes of morphometric and meristic characteristics in maleBarbus lacerta were 21.79 and 5.37 respectively, and in female were 21.22 and 5.60 respectively.Morphometric characteristics were standardized before analyzing for alleviating the errors due to allomotric growth. According to morphometric characteristics, eight accounted for about 67.67% of characteristic diversity, and in the case of morphometric characters, three factors accounted for 64.85% of characteristic diversity within genus were separated. Also, there was observed meaningful difference in only one morphometric character and one meristic character between male and female (p£ 0.05). According to the results of Principal Components Analysis (PCA), distinctions between genuses was not observed and male and female had high overlapping.

In this study, polychaete worms in muddy-sandy coast of Gulshahr in Bandar abbas were investigated. Monthly sampling was conducted during one year from July 2005 until June using a hand corer.According to the results five families of polychaete worms, comprising 6 species, were recorded as macro fauna in the studied sites. The identified families were as following: nereididae, nephtyidae, spionidae, capitellidae, and glyceridae. The most species diversity belonged to family spionidae, while nephtyidae were the most abundant family. Results indicated that the polychaete worms were relatively sparse. This was more considerable in high intertidal areas.

In this study, embryos of Rainbow trout, in 1-30 days post hatching (1-30 dph) were prepared from Jam Raising and propagating center in Kalat nadery, mashhad. Samples were fixed in 10 percent buffered formaldehyde and transferred to laboratory. Samples were prepared through usual histological method. Developmental stages of different layers of skin (epithelium and dermis) were studied under light microscope. According to the results, epidermal cells in single layer with few small mucosal cells and mesenchymal dermal layer during first days were observable. During the second week, by increasing the thickness of epidermal layer, high number of mucosal cells, sensory buds formation and mesenchymal dermis layer were observed until the day 30th, these developmental events were progressed. Having knowledge about the chronological stages of skin development, may be helpful in diagnosis and treatment of fish related diseases and so these results may be helpful for raising them and suitable economic goal.