فصلنامه محیط زیست جانوری
سال سوم شماره 3 (پاییز 1390)

Today most destruction of environmental is the habitats. Hence, the need for methods that can help them to evaluate the habitat, and the over time obtained quality in this habitat. In this study was performed habitat evaluation of the Afghan Pika with Habitat Evaluation Procedure (HEP) and Binary logistic regression. Then, the results of these two methods were compared. Major factors as a variable habitat for species habitat evaluation were measured included: Average of the dominant slope, the aspect, altitude and land cover. Results of the two methods of modeling suggest that land-cover variable has an important role in the Pika habitat suitability which for this species is in rocky areas with cliffs and slopes over 30 degrees with small spaces between the rocks and also the geographical aspects which this species preferred are from north to south. Results showed that the height depending on other variables can be positive or negative, and usually in this region pikas live at altitudes between 2100 to 2300m. Finally, we obtained a model for Pika Habitat Suitability Index (HIS) and also models to predict the Pika presence.

This survey was carried out seasonally from June 2009 to June 2010 to indentify and determine fish diversity of Sarbaz River, Sistan and Baluchestan province. Ten sampling stations were detected along the Sarbaz River with different elevation of 20 to 862 meters above sea level, of which 5 stations were located upper the Pishin Dam and the other 5 stations were located on the down the dame. After capturing the fish using Electroshocker, the samples were transfer to the laboratory for species identification, biometery and data analysis. In total 514 fishes were captured which 12 species were identified. They were belonged to seven families of Cyprinidae, Gobiidae, Balitoridae, Channidae, Cyprinodontidae, Poeciliidae and Mugilidae. Among the identified species, 72% were from Cyprinidae, 12% from Gobiidae, 9% from Channidae, 7% from Balitoridae and 0.01% from Cyprinodontidae family. Three identified species of Gambusia holbrooki, Liza abu and Cyprinus carpio were exotic.

This study was performed for biometrics and investing the status of biological Hawksbill turtles of the Kish Island in 2010-2011. 21 Hawksbill turtles accidentally were biometrics. The obtained results contains the average weight of turtles were 40.143±1.03kg, the average straight carapace length were 65±0.718cm, the average curve carapace length were 71.57±0.559cm, the average straight carapace width were 50.619±0.703cm, the average curve carapace width were 65.214±0.493cm and the average number of eggs were 92.5. The highest correlation between weight and the curve carapace length obtained with the correlation coefficient was r=0.765. The results showed that there is no significant differences between the Hawksbill turtles in the Iranian islands of the Persian Gulf in terms of biometric parameters, but the Hawksbill turtles are bigger than those in the other countries of the Persian Gulf and Oman Sea region and are smaller than elsewhere. The purpose of this research was understanding the biological status of these valuable species for better planning in order to protect them.

In order to study the slaughtering of carp fish under normal circumstances and using the electricity, and how the two methods effect some criteria regarding the flesh, an experiment was carried out in May 2009 for a period of 5 months in the Aquaculture Research Center, Faculty of Fisheries, Gorgan University of Agricultural Sciences and Natural Resources. 40 fishes by average weight of 1300±30g and average length of 47±11cm were used for this experiment. The fish were put in a tank measuring 60×40×30cm, with anode and cathode electrodes, filled with tap water up to 3/4 of its capacity. The anode and cathode were connected to the power supply, and the threshold stimulation, capacity for pain, and death threshold of the fish caused by alteration of the voltage were registered. It was revealed that the threshold stimulation was the same among the carp fish in reaction to electricity, and no significant differences were observed (P>0.05). Pain threshold was the least in silver carp (6±0.38 volts); however, it was the same for carps, grass carps, and bigheads (7.5±0.49 volts). Also, the death threshold was the same for carp fish and bigheads (18±1.21 volts), while the difference was significant (P<0.05) for grass carps and silver carp (15±1.01 volts). Besides, the pH and TVN of carp flesh were measured over a three-month period in ordinary slaughtering and also using electricity, no significant differences were observed in pH immediately after being slaughtered. While at the end of the second and third months, the difference was significant in some species (P<0.05). Measuring the TVN under the two mentioned conditions demonstrated no considerable changes in slaughtering by electricity until the end of the third month, while ordinary ways of killing showed significant changes (P<0.05). In the way, the bigheads having the minimum and the carps and silver carp had the maximum amount of TVN.

Mercury and organic compounds are the most toxic substances for aquatic ecosystems. In the this study, feasibility using of western reef heron feathers as bio-indicator of mercury contamination in the Hara International Wetland. Accumulation of mercury were investigated in body and wing feathers in this species. Furthermore, we evaluated factors influencing mercury levels such as sex and morphometric parameter in the mentioned species. The analyses were carried out using advanced mercury analyzer (AMA 254) according to EPA 7473 method. There were no significant differences between body and wing feathers in Hg concentration in this bird (P>0.05). Results showed that morphmetric parameters such as weight, length and wing length and also sex have no significant effects on total Hg accumulation in this bird. Mercury levels in feather were below the threshold of 5–15mg kg–1 that may affect birds. Results also showed the low bioaccumulation of Hg in the Hara Wetland ecosystem is not so critical. Accordingly, we recommend that the western reef heron can use as a biomonitoring of mercury pollution in this region.

Iranian cave barb (Iranocypris typhlops) is a rare and unique species which as a small population occur in a cave within mountains around Dorrood, in Lorestan province. In this research, the urogenital system of this fish was investigated in terms of morphology and histology. A total numbers of ten specimens of this fish were captured (in spring and summer) and transferred to the laboratory where they were fixed and then different parts of their urogenital system were subjected to anatomical and histological considerations. The results showed that gonads are located over the swimming bladder and behind the digestive tract. Kidneys are also found as a cylindrical mass of tissues reside on the back beside the backbone. Histologically, the most apical region of the kidneys consists of lymphatic tissues, but in the body of gland scare numbers of renal corpuscles are observed. Testes and ovaries are seen as long, sac-like organs which occupy a large part of visceral cavity. From histological standpoint, the testes have scattered seminiferous tubules and functionally are unrestricted. The ovaries are also filled with varied-sized of follicles. The follicles are composed of a large occyte along with a thin layer of follicular cells. According to the results it seems that the reproductive cycle of this fish is seasonal.

Asaccus granularis is one of the geckoes that recently has found in the west of Iranian plateau. There is data deficiency on various fields of this species. In this study, we have tried to get some information about species reproduction and its behavior. So we observed locality type of specimen in west of Iran, Poledokhtar city, Lorstan province and studied them in the nature. The important results of this research are mentioned as: In female specimen of Asaccus granularis, reproduction is not limited to the special period of time and we observed reproduction during spring and summer. This specimen has nocturnal activity and long hibernation. For getting more information, we transferred several samples to the laboratory and reproduction results showed that embryonic period in Asaccus granularis after laying egg until hatchling is approximately 1.5 month.

This study has been conducted during April 2010 to March 2011 in Sistan and Baluchestan waters to evaluate Sphyraena putnamae’s diet. 165 specimens were biometric, dissection and biological study (diet). Diet studied of this fish showed by having average RLG of 0.43 0.003 is highly carnivor and more than 96% of their stomachs were filled with fishes (FP=96%). During study period, food preferences index (FP) was high for Sardinella longiceps (23.8%), Rastrelliger kanagurta (11.1%) and Stolephorus indicus (7.9%) but was low for Sphyraena sp., Saurida sp. and Uroteuthis davancel (1.6% each). CV average for whole period was 71.52% and that showed this fish is abstemious but according to fishing method, CV index in September which was (32%) should be considered as correct index for this type which showed this fish is gluttonous. Average fullness index (FI) was 28.48% in whole period.