فصلنامه محیط زیست جانوری
سال سوم شماره 1 (بهار 1390)

Study of genetic diversity of sea turtles (Eretmochelys imbricata) was conducted using of sequencing of mitochondrial DNA (D-loop region) in the Persian Gulf. 40 dead embryos were collected from the Kish and Queshm Islands. The D-loop region of mitochondrial gene was partially sequenced and phylogenetic relationships between them were obtained. In this expriment 5 polymorphism and 6 haplotype locations were obtained. Nucleotide and haplotype diversity were 0.82 and 0.001 for Qeshm Island 0.56 and 0.002 for Kish Island, respectively. Total haplotype diversity was calculated as 0.71, which showed low genetic diversity in the study areas. The data also was established very high rates of immigration between the populations of two mentioned islands, as the population of turtles in the two islands are considered as a one population. As a point of geography evolutionary, comparing our data with data from previous studies that had been downloaded from a gene bank showed that the population of turtles of the Persian Gulf had been crossed from the Pacific and Oman Sea into this area. On the other hand, evidence of migration of these populations to the west areas was not found.

This research has been conducted in the Babolrood River (Mazandaran province) for evaluation effects of Alborz Dam on biological characters of Squalius cephalus for one year. The sampling was done monthly at behind and below the dam and samples were collected by Electroshoker. In total, 251 Squalius cephalus caught. Total length, fork length, standard length, body weight, age, sex, gonad weight, egg diameter and liver weight measured and recorded. In station 1 (behind the dam), average of total length and body weight for males was 120.44±23.36mm and 23.23±1.43g, respectively. Also, for females average of total length and body weight was 148.33±18.73mm and 39.91±1.41g, respectively. In station 2 (below the dam), average of total length and body weight for males was 117.08±18.31mm and 22.15±7.17g, respectively. Also, for females average of total length and body weight was 131.47±19.61mm and 31.90±1.62g, respectively. The age of the samples belonged to seven age groups. Sex ratio of female to male, at behind and below the dam was obtained 1:1 and 1:1.69, respectively. Changes in diameter of the eggs in behind the dam were between 0.41 to 1.36mm (average 0.94±0.29mm) and at below of the dam were 0.15 to 1.12mm (average 0.75±0.15mm). Absolute fecundity at behind the dam was estimated minimum 1308, maximum 14911 and average 6417 and at below the dam was estimated minimum 1277, maximum 12779and average 5111. The fecundity rate between the two stations, no statistically significant difference (P>0.05). The mean percentage of sexual maturity index (GSI) for male and female at behind the dam was 2.52±2.39% and 4.66±3.83%, and this index for male and female at below the dam was 3.7±2.56% and 4.09±2.61%, respectively. Mean liver index (HSI) for male and female at behind the dam was obtained 1.18±0.09% and 1.25±0.07%, and for male and female at below the dam was 0.66±0.30% and 1.03±0.27%, respectively. According to results of this study, fish in upstream and downstream of the Alborz Dam in many of the reproductive characteristics had a similar situation.

The frog larva is animal that exist abundantly in lakes and ponds. Iran has a good potential for fosterage and expansion of frog larva, that this is due to warm and dry and humid climate qualification (especially in the north and south of country) and desert areas and abundance lakes. The aim of this research was studied a new food material from animal origin in the name of frog larvae powder use possible for nutrition poultry. For this purpose experiments conducted in two stages. First stage, the samples which needed, were collected from ponds and lakes and after drying and grinding for approximate analysis and determine amount of minerals, was chemical analyzed by method of AOAC (1990). Also, powder metabolism energy from frog larvae by mature young cock, were determined by method of Sibbald (1982). Second stage, impact of the frog larvae powder, was studied in the diet of broiler chickens at levels of 0, 2.5 and 5 percent. Body weight gain, feed intake, feed conversion at the end of growth periods, and the final total period, were analyzed and evaluated. At the end of period from any iteration in each treatment, two chickens were killed to determine the weight of breasts, thighs, abdominal fat, liver, gizzard, heart and intestines. The frog larvae powder in 5 percent level in comparison with other treatments caused significantly a lower feed conversion ratio (P<0.05). The level of control treatment and level of 5 percent in comparison with level 2.5 percent of larvae powder were caused significantly more increase of weight (P<0.05). In terms of DMI, there was not significant difference between control and treatment level of 5 percent, but there was a significant difference between treatment and control levels 2.5 percent of larvae (P<0.05). Also different levels of frog larvae did not creation significantly effect on the components of corpse.

In conformity to study and predict the distribution pattern of lizardfish (Saurida tumbil) in the northern Persian Gulf (Hormuzgan province waters), the catch data of 2008 were collected and analyzed. The primary statistical analysis were done using Excel and then distribution maps were provided using GIS–software based on Catch Per Unit of Area index (CPUA). Then to forecast the distribution pattern, the maps of different physical and chemical parameters of sea water consist of temperature, turbidity, salinity, sigma T, oxygen, pH, chlorophyll a, electrical conductivity, sound speed, depth, distance from coast, geographical position and time of towing were prepared and were used as independent value to be assessed with CPUA of lizardfish as dependent value. These maps were used as input of Artificial Neural Networks (ANNs) software of which 60% of data for training, 20% for testing and 20% for validation were applied to prepare the best ANN model. With applying this model on catch and CPUA data, the distribution pattern with emphasize on fishing ground can be predicted for further fisheries management and leading the fishing activities to be concentrated in fishing grounds.

Species diversity is a part of biodiversity which refers to a lot of variety in animals and plants. The examination of species diversity in ecosystems and its changes during different years can help to understand the causes of these changes and lead to manage the problems of wildlife management. This research has identified and examined species diversity and fluctuation of bird populations using total count data in some aquatic ecosystems such as Kashafrood River, Dousti Dam, Tajan River, and Bazangan Lake (wetland) for 5 years. Conducting this study on aquatic ecosystems can be necessary in order to manage the birds and their habitats because of their outstanding values and their overexploitations by human beings. A part of this study was fulfilled based on descriptive and analytical research methods and using library references. In the other part, census data series were analyzed using ecological and statistical software such as Ecological Methodology, SPSS and Excel. Consequently, not only species diversity indices such as richness, heterogeneity, evenness, and their changes but also fluctuation of bird populations and community were calculated in the study areas. Moreover, ecosystem diversity indices (α, β, γ) were calculated and compared with each other in mentioned habitats. Furthermore, Moriseta similarity index was estimated to measure the similarity of the bird communities in the study sites. The most number of birds observed in Kashafrood River was 2667 individuals which belonged to 7 species in 2006. This number in Bazangan Lake was 2139 which belonged to 10 species in 2010. Moreover, the maximum abundance of birds in Dousti Dam and Tajan River have been seen in 2007 which was 4332 and belonged to 36 species. The results showed that the maximum species richness which was 36 observed in Dousti Dam and Tajan River and the minimum richness which was 2 belonged to Kashafrood River. According to heterogeneity and evenness indices, the trend of changes in Kashafrood River’s biodiversity was rising at first and then was falling during the mentioned time period. These two series indices experienced the increasing trends in Dousti Dam and Tajan River. Heterogeneity indices in Bazangan Lake showed upward trend at first, then decreased and again increased in the end of time period, respectively. Moreover, Evenness indices in Bazangan Lake had a downward trend. Based on Moriseta similarity index, the strongest similarity amount was 0.86 among Kashafrood River with Dousti Dam and Tajan River in 2007. The least amount of similarity was zero among Tajan River with Bazangan Lake and Kashafrood River in 2009.

Lead (Pb) is considered as one of the most destructive environmental pollutants causing extremely undesirable impacts on tissues of living organisms. In this trial, physiological and morphological changes in fish liver and gill tissues after Pb exposure for different terms and at various concentrations were investigated. To do so, samples were placed in aquaria containing 0.1, 0.2 and 0.4mg l-1 of Pb at different exposure times (46, 96, 144, and 168hrs). Afterwards fish were removed from the experimental tanks and their gill and liver tissues were sampled in order to determine any histopathological effects. The resulting stained slides were checked using a binocular microscope with a magnification of 10x and 40x. Histopathological changes in liver included sinusoidal extension, vacuolization, hyperemia and hemorrhage, nuclei picnosiation, hepatocyte necrosis, hemocydrine accumulation of melano macrophage cells. Cell acidofication, lymphocyte invasion and focal necrosis were also observed. Gill tissues were damaged by hyperemia, filament and secondary lamellae, mucosal accumulation, telansicatzy, dysplasia pavement cells metaplasia into mucosal cells and gill mucosa, and distal hyperplasia of secondary lamellae. Damages were intensified by an increase in the concentration of the contamination since minor histopathology occurred at 0.1mg l-1 of Pb while levels of 0.1, 0.2 and 0.4mg l-1 of Pb showed major histopathological effects as exposure time increased.

Cryosectioning has gained prominence in comparison to classical fixation، processing and paraffin wax embedding of tissue blocks، since many immunolabelling procedures، as well as routine hematoxylin and eosin (H&E) stains، can be performed on cryosections. However، in this method، the tissues would not be preserved for long time. Therefore، choosing and using of a chemicalfixator، which give the best results can be useful for solving the problem. The aim of this study is determination of current fixator effects on cryosections. For this reason، three kinds of current chemical fixatives substances such as acetone، formalin، and formaldehyde were evaluated for their effects on liver cryosections. Samples which used for acetone evaluation، were cut without fixation. But they were fixed for 10 minute after sectioning. Formalin and paraformaldehyde fixed samples were cut after fixation. All sections were stained by hematoxyline and eosin and were studied by light microscope. Paraformaldehyde fixed samples had better results in both preservation and staining quality rather than other fixatives. So، we concluded that for fixation of cryosections، paraformaldehyde is the best choice among formalin or acetone for H&E staining in light microscopy level.

In this study، the effect of vitamin C enrichment on its accumulation in Artemia nauplii and Persian sturgeon fish larvae and also survival rate of fish larvae when they exposed at salinity stress، were investigated. Artemia nauplii were hatched and enriched with different percentage of vitamin C (10، 20 and 30%) in form of Ascorbyl palmitate، emulsified in lecithin during 12 and 24h، overall 6 treatments each with 3 replications and were given to fish larvae، 250ind. /25L tank with initial DW of 4. 3mg for 15 experimental days. At the end of experiment، a numbers of fish larvae were selected randomly and exposed to different salinities (6، 12 and 18ppt) with using the Caspian Sea water، diluted with distilled water and concentrated with excess salt، for different hours (1، 2، 4، 8، 24، 36 up to 72h). Then، mortality percentages were computed. The vitamin C analysis of treatments with HPLC showed the accumulation it in Artemia nauplii and fish larvae were significantly compared with control groups (P<0. 05). The synthesis of vitamin C in fish larvae kept in 20-22ºC water temperature during 15 experimental days was 2µg/g DW of fish. At the end of experiment، the fish carcass weight was 69mg DW contained 41. 2µg vitamin C/g DW of fish while at the beginning، was 11µg vitamin C/g DW. Unenriched Artemia nauplii after 24h، faced with vitamin C downfall، decreased from 312 to 294µg/g DW of naupli but the final results showed the increasing trends of vitamin C content in treated Nauplii and fish larvae which had directly related with increasing in vitamin C percentages and enrichment period. The mortality was observed among the control fishes after 36h exposed to 6ppt salinity (survival rate 75%) and increased to 72h (survival rate 25%) while in all treatment the survival rate were 90 to 100% without any differences significantly even in 12ppt salinity (P>0. 05). We conducted that the possibility of releasing the enriched Persian sturgeon larvae with vitamin C to the Caspian Sea directly can reduced mortality of fishes more than those that released to rivers and also increase larvae survival rate.