فصلنامه فیزیولوژی و بیوتکنولوژی آبزیان
سال پنجم شماره 4 (زمستان 1396)

Today, due to adverse effects of chemical antioxidants, natural antioxidants have attracted considerable attention. Seaweeds and fish protein hydrolysates are rich sources of natural antioxidants and have an important role in keeping the quality of food served during processing and storage. In this study, the antioxidant activity of protein hydrolysate from the common kilka (Clupeonella cultriventris caspia) and brown algae (Colpomenia sinuosa) extract was investigated. The results showed DPPH and hydroxyl free radical scavenging methods, at a concentration of 2%, respectively 2.56±0.89% and 71±1.50% and amount of reducing power of iron at a concentration of 2% was 0.47±0.007 in protein hydrolysate and for algae extract at concentrations of 200 (DPPH) and 400mg/mL (Hydroxyl free radical scavenging) were respectively 2.68±1.50% and 71.87±13.25% and amount of reducing power of iron in concentration of 1.07mg/mL was 0.128±0.003. In conclusion, protein hydrolysate from the common kilka (C. cultriventris caspia) and algae (C. sinuosa) extracts can be considered as a potential source of antioxidant compounds.

The aim of this study was to evaluate the effect of fetal bovine serum (FBS) and temperature changes on the cultivated ovarian cells of Liza klunzingeri. For this purpose, 10 fish weighing 45 to 50 grams were caught and transferred to the laboratory. After disinfecting the body of the fish with 70% ethanol, the ovarian tissue was removed from the body and divided by scissors into small pieces. The ovarian cells were aspirated by using trypsin enzyme and were cultivated in the flasks containing L-15 medium under different temperature conditions (20, 25, 28, 30 and 32°C) and the serum concentrations of bovine embryos (0, 10, 15 and 20%). Cell count showed the maximum density of L. klunzingeri ovarian cells was observed in 15% FBS concentration, while temperature variations had no significant effect on cell proliferation. In conclusion, the most suitable conditions for the culture of ovarian cells in L. klunzingeri are the use of FBS 15% and temperatures above 20°C.

Due to the abundance of Holothurialeucospilota in the Persian Gulf and cytotoxic properties of their synthesized terpenoid compounds, in this study, we examined the cytotoxic effect of lanosterol from triterpenoids. The sea cucumber muscle samples were dried and extracted with acetone. The extract was semi purified by silica gel column chromatography using n-hexane and ethyl acetate to get lanosterol. The cytotoxic effect of lanosterol checked by using XTT assay on oral epithelial cancer cell (KB/C152) and human embryonic kidney cells (Hek293) cell lines. The IC50 value of lanosterol extracted from sea cucumber muscle in KB/C152 cell line was 6.36µg/mL but it was not toxic to Hek293 cell lines. The study demonstrated that extracted lanosterol from H.leucospilota muscle had strong cytotoxic effects that can be used as an anticancer drug.

Sperm cryopreservation has been considered as one of the gamete management strategies for artificial reproduction in sturgeons. Bester is a promising fish in sturgeon aquaculture but sperm cryopreservation of this fish had not been studied before. In the present study, changes in motility indices of bester sturgeon spermatozoa were investigated after one year of cryopreservation with two different extenders. The mean percentage of motility, total duration and VSL of samples diluted with E1 extender were 47.57±4.7%, 96.77±6.61s and 125.39±40.81µms-1, respectively and reached to 33.71±5.36%, 102.5±5.24s and 60.84±24.55µms-1, respectively after one-year preservation. Diluted samples with E2 extender showed 41.47±3.06%, 102±9.01s and 110.26±31.19µms-1 for these parameters at sampling day and reduced to 28.51±4.55%, 82.67±10.11s and 52.77±27.6µms-1 after one-year preservation. Results of this study revealed that there are no significant differences among studied motility indices between two extenders (P>0.05). These findings could be regarded as basic information to improve long-term cryopreservation method of bester semen in future.

The aim of this study was to investigate the growth parameters and carcass composition of common carp (Cyprinus carpio) treated by silver nanoparticles and probiotic Lactobacillus casei. A total of 250 fry carp with mean weight 23±2.4g were divided into three treatments include without probiotics, probiotics level A (106 CFU/mL) and level B (107 CFU/mL) for 42 days. Each group was exposed to 50% of nano-silver LC50 for 10 days. Protein was determined with total nitrogen by a Kjeldahl method, crude fat by fat dissolving in the ether and determines where to Soxhlet, ash by putting the sample in electric oven and moisture was measured by drying the samples. Results showed that moisture, body weight index (BWI) and condition factor (CF) were reduced in nano silver treatments; however, fat, protein and BWI increased within the influence of nanosilver. Although neutralize the effect of probiotic on nanosilver had the positive effect on moisture, fat and BWI indices. In conclusion, probiotics neutralize some undesirable effects of silver and had a positive synergistic effect on the growth of common carp fry.

The cultivation of rice and shrimp globally has expanded significantly due to its economic efficiency. The purpose of this study was to investigate the effect of shrimp and rice combined cultivation on shrimp quality after salting and during its storage and rice crop. Therefore, shrimp biochemical compounds after salting were analyzed every two weeks, from week 0 to12. In addition, shrimp growth indices were calculated during raring period every two weeks (for 12 weeks) and rice morphological and performance indices were evaluated at the end of 12th week. The results of the evaluation showed that in general, all of the evaluated indices of the shrimps such as specific growth rate, conversion factor efficiency and survival percentage and also the chemical composition of shrimp bodies such as protein, crude fat and moisture content in shrimps obtained from combined cultivation with rice were favorable. In addition, rice and shrimp cultivation had significant effects on all morphological traits and rice yield, such as total leaf chlorophyll content, plant height, tiller number, tillers in each cluster, flag leaf length and width, spike length, grain yield, number of grains per spike, 1000 grain weight, number of filled grains per cluster and the amount of biomass of rice plants grown under combined treatment of rice and shrimp compared to chemical fertilizer treatment.

In this study, the intraspecific variations in urohyal bone and otolith morphology were investigated in Capoeta saadii (Heckel, 1847) from Kerman Basin. A total of 48 specimens from four populations (Zarand, Bardsir, Kouhbanan, and Kahnooj) were collected from Kerman province and preserved in 75% ethanol. The urohyal bones and otoliths were extracted by the standard methods, and their morphology described and morphometric characters were analyzed. The urohyal bones are characterized by the following features: the anterior part without appendage, the ventral surface triangular in shape and with slit in the posterior part of the urohyal bone, the ventral sides is almost wide. The asteriscus otoliths were gyro-type and often with no clear rostrum and pseudorostrum, the inner part concave and the outer part convex, the ventral rim is straight and serrated. The morphometric analyses indicated that the L/PosD, L/In.O.D, W/PosD and W/In.O.D have the most important role in differentiation of the studied populations. In the case of asteriscus, ML/FSL and ML/FHL are important in differentiation of the studied populations. Based on the results of the current study, it can be concluded that variations in morphology of the urohyal bone and asteriscus in cyprinids can be important not only in the species discrimination but also for estimation of the intraspecific differentiation (variations among populations) in allopatric populations. By considering the pattern of variation of the studied structures, the Zarand population is differentiated from the others, and this can probably be resulted by its geographic isolation.