JOURNAL OF MARINE SCIENCES AND TECHNOLOGY
Year:2017 | Volume:16 | Issue:1|Papers Count:5

This study was carried out to evaluate the effect of varying dietary levels of protein (45%, 50%, 55% and 60%) and energy (20, 22 and 24 kjg-1) on the growth, survival rate, food performance and body chemical composition of sobaity Juvenile.36, 300 Lit polyethylene containers equipped with a flow-through water system (with 1 Lit/min water exchange) were provided and each stocked with 18 Juvenile fish (27.99 ± 0.14 g weight). During the rearing period, a biometric measurement was carried out once fortnightly. After a 56-day rearing period, results showed the significant effect of the treatments (the interaction between protein and energy) and the varying levels of protein and energy on the growth and food performance, survival rate and body composition) P£0.05) of the fish, but the effect of the dietary protein was not significant on the FCR, PER, fat and body crude fiber (P>0.05). Also, the effect of dietary energy was not significantly effective (P>0.05) on the growth and food performances, but was significantly effective on the survival rate and body composition) P£0.05) of the fish. Results also showed the highest amount of growth of the fish in the diet with 60% CP and 24 kJg-1 energy, the highest survival rate in the diet with 55% CP and 22kJg-1 energy and the best FCR and PER in the diet with 50% CP and 24 kJg-1 energy. According to the results of the present study, 50% CP and 22 kJg-1 energy are recommendable to cover the dietary protein and energy requirements of sobaity fish in the Juvenile stage.

In the present study, the efficiency of the flavonoid and aqueous extracts ofM. communis L. tree leaves, a recognized Iranian medicinal plant, were assessed in vitro on the growth of isolated fungi, Saprolegnia and Fusarrium using the agar disc and well diffusion methods in flat-bottom microplates in the presence of various extract concentrations. The isolated fungi were sampled from the fertilized eggs of rainbow trout fish incubation farms. The leaves were collected from the natural habitats of the province of Chaharmahal-o-Bakhtiary in the early-summer and extrcation took place through maceration methods with water solvent as well as by flavonoid extraction methods with methanol solvent. During the succeeding trials, the antifungal effects of the flavonoid extracts (by the disk diffusion method) and the aqueous extracts (by the well diffusion method) against isolated Saprolegnia were revealed by MFC (Minimum Fatal Concentration) values 50 and 100 mg/ml, respectively. The only effect of the methanolic and aqueous extracts of M. communis leaves revealed the in vitro inhibiting effect on the growth of isolated Fusarium by MIC values 25 and 12.5 mg/ml, in disc diffusion and well diffusion methods, respectively. The antifungal effects obtained by the extracts had more effective aspects on isolated Saprolegnias in comparison to Fusariums. The results of the study indicate that M. communis could be considered as a potential candidate for designing effective antifungal extracts suitable for the treatment of the fish eggs fungal infections.

The main goal of using floating breakwaters is to provide a sheltered area of calm water in a coastal zone. In the present research, for analyzing the hydrodynamic modeling of pontoon floating breakwaters, the AQWA module of ANSYS was selected. The main parameters that have been considered in this research are the patterns of significant wave height, wave period, and draft and the width of floating pontoons. Wave transmission coefficient can be obtained from water surface changes in any point of the leeward. Results of the numerical modeling demonstrate that a pontoon floating breakwater with a relative width of greater than 0.4 has an appropriate performance. Also, it has been found that the transmission coefficient of pontoon floating breakwaters will be in the range of 0.35 to 0.60 if the relative wave period changes in the range of 1.5 to 4.

Echinoderm species are important members of benthic communities existing in subtropical to polar regions. They have an important role in nutrient cycles and other communications between organisms.This study investigated the distribution and abundance of brittle star Macrophiothrix cheneyi in the intertidal zone of Chabahar bay, the Oman Sea. Sampling was randomly done bimonthly using a square meter quadrate during one year, from November 2008 to September 2009, at 5 selected stations. According to the results of a Kruskal-Wallis analysis, the density of this species at different sampling times and stations revealed a significant difference (P<0.05). The highest frequency of this species was measured at the station of Chabahar University of Maritime and Marine Science in September 2008 (± 1.54 3.58 ind.m-2) and its lowest frequency was measured at Kolbe Qavasi station during the whole year except January. The difference in abundance (between the different months and stations) seems to be influenced by ecological (bed, food and shelter) and biological factors (fertility, hunting and competition). The investigation of distribution revealed that brittle stars in the intertidal zone under study followed random and patchy dispersion. The results of the stability indicator revealed that though the brittle star was rarely found during some periods, it was a common species in September 2008.