فهرست مطالب

Caspian Journal of Environmental Sciences - Volume:15 Issue:2, 2017
  • Volume:15 Issue:2, 2017
  • تاریخ انتشار: 1396/05/24
  • تعداد عناوین: 8
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  • H.R. Esmaeili*, R. Choobineh, H. Zareian, A. Gholamhosseini Pages 97-112
    The life history traits and gonad development of an endemic cyprinid fish, the spotted barb, Capoeta mandica (Bianco & Banarescu 1982), from southern Iran was investigated by regular monthly collections from February 2006 through January 2007 and on the basis of microscopic and macroscopic analyses. No information on the spawning characteristics of the fish are available to date. A total of 335 specimens were captured using electrofishing including 253 males and 102 females, resulting in 2.5:1 (male: female) sex ratio, which is significantly different from the expected ratio. The commonly known five standard maturation stages were determined based on the size, shape and weight of the gonads, degree of occupation of the body cavity, presence or absence of ripe oocytes, or milt, diameter of the oocytes in the ovary, and histological observations. These stages were correlated to the reproductive indices. The ovum diameters ranged from 0.04 to 1.31 mm, with the highest mean value in May. The condition factor of male and female specimens was the highest in April. The female GSI increased from March to May, peaking in the middle of spring and decreased significantly in June. Based on the gonad maturation stages, gonadosomatic index (GSI), modified GSI, mean egg diamete­r, condition factor (K) and Dobriyal index (DI), it was concluded that the spotted barbspawns during May and June. The provided data, contribute baseline data towards management ecology and conservation of this endemic fish species.
    Keywords: Cyprinidae, Gonad histology, Reproduction indices, Spotted barb
  • A. Khosravi, M. Shaker Golmakan, A. Teimori* Pages 113-123
    Phenotypic variations in fish body and scale shape were investigated among the three populations of Aphanius dispar (Rüppell, 1829)in Southern Iran through the use of landmark-based geometric morphometric analyses. This species is widely distributed in the region, and therefore, considerable morphological variations exist among the geographically allopatric populations. Based on the Principle Component Analysis (PCA), variation in body shape of the females is prominently related to the dorsal fin region, while in the males it is related to the dorsal fin and caudal peduncle. Moreover, the shape variations in the scales are obviously linked to the tip of anterior portion of the scales, and the left and right boundaries between anterior and posterior regions of the scales. The lateral sides of the fish scales in site I are concave, while they are laterally convex in sites II and III. The observed variation seen in the fish body shape and scales among the three studied sites are probably caused by the different ecological conditions of their habitats particularly variation in water flow.
    Keywords: Tooth-carps, Adaptation, Habitat changes, Water flow
  • S. Eagderi*, B. Mojazi Amiri, H. Poorbagher, M. Nasrollah Pourmoghadam, N. Nemati Mobin Pages 125-134
    The present study aimed to investigate effects of the heavy metal Cd on the sperm morphological indices of Caspimyzon wagneri. The sperm were exposed to 0.01, 0.1, 1, 10, 100 and 1000 mg.L‑1 Cd for three minutes, three and 36 hours. The sperms exposed to Cd showed an increase in the length, width and surface of the head, flagella degradation and slightly flagella breakage. With increase of Cd concentration or the exposure duration, the damages found in sperms increased. But when exposure to contaminant exceeds than certain period of time, damage effects caused changes in the sperm structure as head length reduction and head width increasing and thereby reducing the sperm’s head surface, complete cutting of flagella at all samples and deformation of the sperm’s head from oval to circular, which these changes became visible during 36 hours of exposure to cadmium. Therefore, the results revealed that the arrival of pollutants including cadmium to the natural reproduction ground of this species due to induction the harmful effects on sperm morphology factors will have adverse effects on sperm function and fertilization rate and reduce them, and as such will be considered a serious threat to the survival generation of this rare species.
    Keywords: Sperm, Morphological structure, Cadmium, Caspimyzon wagneri, Caspian Sea
  • Y. Keivany*, M. Ghorbani, F. Paykan-Heyrati Pages 135-145
    Reproductive characteristics of Mossul bleak, Alburnus mossulensis, a native species of Cyprinidae family in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. Five hundred and fourty three specimens (256 females, 159 males and 31 immature) were caught by a sein net (5 mm mesh size). The collected sampeles were anesthesized in 1% clove oil solution and transported to the laboratory on ice and subjected to dissection and biometric measurments. Age of males and females ranged from 0 to 5 years. The sex ratio was 1M: 2.2F (p
    Keywords: Cyprinidae, Fecundity, Age, gonad development, Gonadosomatic index
  • M. Tavakoli*, M.R. Behrooz Khoshghalb, D. Kor, H. Ghadirnejad Pages 147-156
    The sturgeon stock assessment was performed to aim at estimation of absolute and relative abundance and determination of species composition at lower 10 m depths using the Si-Sara2 RV vessel in the Iranian coasts of the Caspian Sea in Guilan, Mazandaran and Golestan provinces during 6-30 September 2011-2012. In this study, 40 stations were selected on the basis of stratified random sampling design and then the stock estimation was performed using the swept area method. The study was carried out using bottom trawling with 9 m head rope. The time and speed of trawling in each station were 30 minutes and 2.5 knots respectively. The Catch per Unit of Effort (CPUE) in 2011–2012 were 7.03 and 6.96 individuals per trawling, respectively. The catch per unit of area in these years were found to be 1662 and 1644 fish in nm2, respectively. Total abundance of sturgeon juveniles was 13,327,164 individuals in 2011. So, the species composition included A. persicus (87.8%) and A. stellatus (12.2%). Total abundance of sturgeon juveniles was found to be 14,364,882 individuals in 2012 and the species composition comprised A. persicus (61.4%) and A. stellatus (38.6%). In 2011 the biomass of sturgeons in Iranian coastal water of the Caspian Sea was 295 tons and the composition of biomass included A. persicus (81.5%) and A. stellatus (18.5%), respectively. In the cruises conducted in 2011, this amount was estimated to be 217 tons comprising A. persicus (54.2%) and A. stellatus (45.8%), respectively. The results of this study in 2011–2012 showed remarkable abundance of juvenile sturgeons in Iranian coastal waters of the Caspian Sea in late summer and early autumn. So, by conserving these valuable stocks, the number of spawners will be increased in the future.
    Keywords: Caspian Sea, Sturgeon, Stock assessment, Bottom trawling, CPUE
  • A. Krika*, F. Krika Pages 157-164
    Mencha River is one of the largest river in the region of Jijel, Algeria. The human activities such as urban discharges, industrial, agricultural and livestock have significant effects on the quality of water. Because of its importance in the agricultural activities and dense population residing at its banks, the river faces several challenges from various anthropogenic activities. This situation exposes surface water to a severe pollution. The objectives of this study are to use different indexes to assess the current pollution status in Mencha River. Indexes used in this study were Organic Pollution Index (OPI) and Microbiological Quality Index (MQI). Based on the data collected throughout this study, results indicated that the upper reaches of the river (station 01) has had good water quality (OPI=4, MQI=4), while the station 04 presented a poor quality (OPI=2.75, MQI=2.33). Indeed, several pollution sources exist in this site. The agricultural activity, among different sources, was the strongest point in the downstream section of the river, as it contains high amounts of chemicals, causing major decrement in water quality. The used indexes also showed that at stations 02 and 03, the water quality was moderate (OPI=3.25, MQI=3). This study can be used to support the evaluation of regulatory and monitoring decisions.
    Keywords: Surface Water, Pollution Organic Index (OPI), Microbiological Quality Index (MQI), Mench River
  • E. Milani, S. Saeidi Mehrvarz*, H. Gholizadeh Pages 165-180
    The Abshar protected area with 3639 ha and an altitude ranging from 400-855 m a.s.l. is one of the forest areas that due to its topography is covered by Carpinus betulus, Parrotia persica and Diospyros lotus speices. The floristic study of this area is long with sampling plots. The floristic-physiognomic investigation showed that flora of this region included 99 plant species which belonged to 81 genera and 49 families. The largest family was Rosaceae with 10 species. Classification based on life form spectrum indicated that geophytes (31.31%), phanerophytes (29.29%), hemicryptophytes (25.25%) and therophytes (14.14%) comprise the plants in the studied area. The results of chorological studies showed that the chorotype form Euro-Siberian elements (32 taxa, 32.32%) were the most important phytochorion in this area. Long period of wetness during the growing season and relatively high annual precipitation are the reasons of the high proportion of geophytes existence in the studied area. Phytogeographical comparison of the Abshar protected forest and the other forests in north of Iran identified two peaks in phytochoria curves, one in Euro-Siberian and the other one is in the Pluriregional elements.
    Keywords: The Abshar protected area, Shirgah, transect, Floristic, Chorological
  • B. Sotoudeh Foumani*, T. Rostami Shahraji, S. Mohammadi Limaei Pages 181-199
    The area of natural forest in Iran is approximately 12.4 million hectares, comprising 7.5% of the total area of Iran. Forest management in the country was changed to the legislature after order of the Forest Nationalization Law in 1963. With civilization development, pressure on forests was significantly increased. In the early 20th century a system of development planning began as a series of seven-year cycles, focusing on accelerating economic growth by improving capital-intensive industries and replacing religious and social traditions with rapid modernization. There are some essential challenges ahead of the common assets administration of the Hyrcanian forests which have many conflicts between including executive associations and regulations. So that, forest policy has been structurally shifted in policy sector, from private administration to governmental management. This paper has provided a literature review discussing the forest policy administration in Iran and its essential structural shifts during the last century as well as data collection from relevant governmental and private organizations.
    Keywords: Iranian forests, Forest policy, Political power, Climate change adaptation