Journal of Animal Research
Year:2016 | Volume:28 | Issue:4|Papers Count:12

The Zarde fish, Capoeta damascina is an carp fishes with no remarkable research concerning its biology. Regarding the important role of digestive tract in survival of animals we tried to study this aspect of the taxon’s biology. To perform this task, specimens were collected from Sezar River and the biometric characters of them were measured. Following that their digestive tract were removed and small pieces of different parts of digestive system were prepared for histological examinations. Anatomical and histological studies performed here revealed that the digestive tract consists of two main parts, esophagus and intestine. The wall of this tract is composed of the mucosa, submucosa, muscular is and serosa. Goblet cells of the both parts reacted positively to periodic acid schiff and alcian blue stains. In general, the results demonstrated that from histological and histochemical standpoint, the digestive tract of Zarde fish is similar to what reported in other species.

The present study investigated some of seminal plasma indices (ionic and organic composition), osmolality and their relationships in Argyrosomus hololepidotus semen. The concentrations of Sodium (Na+), Potassium (K+), Calcium (Ca2+) and Magnesium (Mg2+) ions were 103±26.33, 25.34 ± 13.03, 0.76 ± 0.22 and 1.08 ± 0.35 mMol/L respectively. Seminal plasma contained 0.45±0.26 mg/ dL total protein, 21.77 ± 7.56 mg/ dL cholesterol, 5.32 ± 2.16 mg/ dL glucose, 117.38 ± 28.17 mOsmol/ Kg osmolality, 4.06 the Na+/k+ration and 0.02 the Ca2+/K+. Results showed the significant positive correlations between Na+- osmolality (r=0.80, P<0.01), Na+- cholesterol (r= 0.794, P<0.01), cholesterol- osmolality (r=0.841, P<0.01), cholesterol- glucose (r= 0.684, P<0.01) and glucose- osmolality (r=0.629, P<0.01). There were also significant negative correlations between Na+-protein (r=-0.664, P<0.01), K+- glucose (r=-0.557, P<0.05), Ca2+- cholesterol (r=- 0.476, P<0.01), protein- Ca2+ (r=- 0.675, P<0.01), Ca2+- glucose (r=-567, P<0.05) and protein – osmolality (r=-0.554, P<0.05). It can be concluded that a higher K+content has negative effect on glucose content. Variability in the ionic composition and osmolality of seminal plasma of fishes is mainly due to intra- specific differences in testicular secretions.

Interspecies competition for space and the factors affecting competition are the questionable coastal ecological issues of interactions. Current study aims at studying the competition between two invasive species, Amphibalanus improvisus and Mytilaster lineatus, in rocky shores of Caspian basin. A field study has been conducted distance sampling on 10 stations, once every two month from September 2013 to July 2014, sampled with 15 × 15 cm quadrat, placed at random along natural and artificial rocky shores, from Astara to Babolsar. The algae percent cover has been estimated by 50 × 50 cm quadrate. The mean changes and average variability of water temperature, Salinity, dissolved oxygen and conductivity have been measured as follows: 16.480C, 9.87ppt, 9.89 ppm and16.52m/s. The results for A.improvisus and M.Linatus were as follows, respectively: average number, 404.75 and 327.33; percent cover 36.83 and 29.97; weight 17.8g and 26.47 g. According to tukey test, a meaningful difference is shown to exist among stations and the dominant of M.Lineatus was higher compared to A.imrovisusin stations No.3, 4, 6. Although the results of present study showed that the inter annual mean and standard deviation of algae percent cover was 37.75, the results of tukey test did not show a statistically significant difference between stations. The results of One-way ANOSIM test suggested that the stations No.3, 4, 5, 6 have the most habitat similarity and environmental factors affecting their distributions, and besides dominance over benthic, the existing competition for space among two species results in favor of bivalve, mostly.

The larval stages of demersal Fish larva were sampled from coastal waters of Hengam Island in the Persian Gulf Hormuz Strait region. Sampling was conducted from late winter 2012 to early autumn 2013 seasonally. The larvae were collected with plankton net 300μm mesh size using oblique towing method from near bottom to sea surface in 6 stations with three replicates. A total of 6832 pieces of larvae were collected in the families including (Gobiesocidae, Bothidae, Blenniidae, Tripeterygiidae, Soleidae) included 20% of total catch. Tottaly 4 species were identified includingPseudorhombus sp. of family Bothidae, Omobranchus sp. and Parablennius thysanius of family Blenniidae, Helcogramma steinitzi of family Tripeterygiidae. The highest abundance of fish larvae (3.59 ind/100m3) found in the autumn and the lowest frequency (0.34 ind/100m3) calculated in the summer. The results of the ANOVA showed a significant difference (p<0.05) in abundances between summer and other seasons. In the result of spearman's correlation test show that the temperature has the higher positive correlation with density of family Blenniidae (p<0.01). The highest Shannon index was calculated in autumn but the most value of dominancy (Simpson index) found in summer.

Nowadays, human activities such as discovery, migration, trade and tourism mostly are influenced distributional pattern and range of some species in this research, patterns of current and future (2040) distribution of H. flaviviridis which is a species with distribution by anthropogenic introduction, have been studied. In total, 19 bioclimatic variables have been extracted from Worldclim website and then seven non correlated bioclimatic variables and 40 point localities were performed using maximum entropy method (MaxEnt) software. Results of species distribution modeling showed coastal southern of Iran having highly habitat suitability. Results of forecasting showed eastern Iran in Sistan and Blouchistan province, central the Iranian plateau, Khuzestan province having habitat suitability in the lower suitability levels. However, the most important bioclimatic variables which contributing in modeling on distribution pattern of H. flaviviridisincluding precipitation seasonality and precipitation of the warmest quarter. Recognition alien species is necessary in order to mange priorities, maintain biodiversity, prevent and control invasive alien species.

province during summer of 1391 were studied. Sediment samples were collected from 4 stations (Dylam, Genaveh, Dayir and Bushehr). Muscle and liver of 80 fish were dissected. Nitric acid method was used for tissues digestion and nitric-perchloric acid method was applied for sediment digestion. Atomic absorption spectrometer used in order to determine the metals concentrations. Mean concentrations of Ni, Cu, Co, Pb and Cd in the liver were, 2.7, 80.3, 2.8, 2.56 and 3.1 respectively, in the muscles were 1.2, 4.28, 1.32, 2.7 and 1.6 respectively, and in the sediments were 0.68, 14.4, 2.8, 49.5 and18.7, respectively. Differences in heavy metals concentrations among the species is likely to have resulted from metal bioavailability, hydrodynamics of the environment, changes in tissue composition, stations of collection and sources of pollution within the Persian Gulf.

Anesthetics are used with increasing frequency in aquaculture, mainly to reduce the stress and to prevent mechanical damage to fish during handling. Present study is the first study on the effect of emulsion of spearmint (carvone) oil and methyl salicylate (ECMS) on anesthesia of Rutilus frisii kutum with average body weights 3.35±0.25 g in Iran. The water temperature was 20°C and pH was 8.1 during the investigation. Fish were exposed to the concentrations of 197, 263 and 395 ml/L of ECMS. Results showed that induction time decreased significantly with increasing of the concentration of ECMS (P<0.05). There is also no significant difference between recovery time and opercular rates in experimental groups (P>0.05). Opercular rate firstly increased and then slowly decreased with increasing the concentration of anesthetic. Also, no mortality was observed in the study. The results of this study show that applications of spearmint and methyl salicylate oil emulsion in 263 ml/L level, can be suitable for anesthetization of Rutilus frisii kutum.

Genus Alosa Linck, 1970 is widely distributed in the Caspian Sea but in Southern region of Caspian Sea identified species has not been reconsidered during past ten years.in order to study the population diversity ofAlosa species of Iranian waters of Caspian Sea, samples were collected over a period of one year from Chaboksar, Chaf and Kiashahr coastal water by beach seines and gill net. A total of 430 specimens were examined to identify four species namelyAlosa braschnikowi, Alosa caspia, Alosa kessleriand Alosa saposchnikowi. A. braschnikowi was the most frequent species and Alosa saposchnikowihad the lowest prevalence. A. braschnikowi and A. caspia had the highest and lowest mean fork length and weight, respectively. Sex survey showed that females were dominant in all species. The age rang was of 2 to 7 years old.

The kind of feeding and feed conditions affect on fish quality. They also affect on proximate composition and fish shelf life. Hence the aim of this study was the evaluation of qualitative changes among the carps culturing in a pond (CCP), an under controlled place (CL) and marine carp (MC) during refrigeration. In order to perform this study, the fish was stored at 4◦C for 15 days. During the storage time, qualitative changes were evaluated with recording changes in their Total Volatile Bases Nitrogen (TVN), Thiobarbiotic Acid (TBA), Free Fatty Acids (FFA), pH, WHC and heme iron. The proximate compositions of fish fillet (moisture, protein, lipid and ash) were evaluated. The results showed that the highest value of moisture and the lowest value of lipid were observed in CCP. Protein levels among different treatments did not have significant difference. TVN, TBA and FFA increased during refrigeration. pH changes didn’t follow an identical pattern in all treatments. The highest level of TBA and FFA and the lowest level of heme iron were observed in CCP. The highest level of WHC was observed in marine carp. The results showed that CCP had more potential to decay.

Culture of many zooplankton species is mostly depended on microalga because they have many of specific key properties for zooplankton ingestion. In present research, ingestion rate of copepod Eucyclops serrulatus was determined using two green microalga of Scenedesmus quadricauda and Chlorella vulgaris at different algal concentration (very low, low, medium, high). Results showed that ingestion rate of copepod E. serrulatus was significantly (P<0.05) increased when algal density of S. quadricaudaand C. vulgaris increased. The mean maximum ingestion rates of E. serrulatus were obtained 0.402 ´ 104 and 0.047 ´ 104 cells/h at high algal concentrations of S. quadricauda and C. vulgaris, respectively. In addition, our findings showed that there was linear relationship equation between ingestion rate and algal concentration which changed with used algae species. Comparison of measured ingestion rates showed thatE. serrulatus could be cultured at algal culture media, but suitable performance obtained with C. vulgaris. The higher ingestion rate of E. serrulatus on C. vulgarismay attribute to its smaller size and sperical shape of cells.

In order to estimate the length- weight relationships and variations in the morphological straits of Aphanius vladykovi, 60 samples were caught from Madar-Dokhtar (mean standard Length: 32.71±4.01) and Ordoval springs (mean standard length: 30.72±3.92), during the fall season (30 specimens for each location). The growth pattern in Gandoman was negative allometric for both males (b=2.06) and females (b=2.53), while in Naghneh the growth pattern was Isometric and positive allometric for males (b=3.20) and females (b=3.46), respectively. The condition factor value (CF) indicated the better nutritional conditions in Gandoman compared to Naghneh (P<0.05). Based on morphological futures, a high morphological variation of A. vladykovi was observed across regions. Based on PCA, body depth is the variable with the greatest explanatory power. The populations were identified based on their locations across CVA (P<0.05) and no significant differences were observed between males and females in each location (P˃0.05). Consequently, it can be addressed that the differences in condition factors and morphological indices between two populations of A. vladykovi in two different upstream locations of Karun River are related to factors such as genetic potentials, habitat diversity as well as geographical distance. It seems that accumulation of distinctive traits under the effects of environmental parameters including temperature, nutrients and water depth is anticipated to be continued, so there is a probability of potentially allopatric speciation. Finally, it is proposed that the fishes of these two locations must be considered as two genetically and morphologically separated stocks in terms of fisheries conservation practices.

Considering to different effects of ascorbic acid on special body parameters, this study was conducted to investigate the effect of ascorbic acid on reproductive function in rainbow trout (Oncorhynchus mykiss). Three diets supplemented with 0, 100 and 1000 mg/kg L-ascorbyl-2-polyphosphate as vitamin C, were fed to rainbow trout broodstocks in three replicates for 16 weeks. Broodstocks with average weight of 812 ± 1.5 g were acclimated to experimental diet for two weeks. After 16 weeks, with the reproductive examination, some parameters including fecundity, percentage of egg fertilization, percentage of eyed egg, degree days to the eyed stage and degree days to alevin stage were measured. Results showed that in all parameters, significant differences were observed among the treatments (P<0.05). Degree days to the eyed stage and degree days to alevin stage had the highest values in fish fed diet without ascorbic acid and the minimum values were related to the diet containing 1000 mg/kg ascorbic acid. Also the highest amount of fecundity was observed in fish fed the diet containing 1000 mg ascorbic acid/kg (P<0.05). With having suitable effect on reproductive performance with feeding of dietary ascorbic acid, the results of the present study recommend that this vitamin should be added with the high level in rainbow trout broodstock diet at least before propagation.