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Showing 2 results for Eagdari
Volume 3, Issue 2 (6-2015)
Abstract
The pollution of aquatic ecosystems may affect natural reproduction of fish populations by decreasing the fertilization efficiency. Among the various sources of pollution, heavy metals are important group, being found in both freshwater and marine environment. The present study investigated changes of sperm characteristics of Caspimyzon wagneri when exposed to Manganese (Mn). Spermatozoids were exposed to 0 (control), 0.01, 0.1, 1, 10, 100 and 1000 mg l‑1 of Mn, duration of sperm motility and percent of motile sperms were measured using a light microscope and digital camera as a semi-quantitative method. Total duration of spermatozoids motility decreased with increase of Mn concentration in all treatments. This study indicated that Mn could seriously affect the reproductive success of the Caspian lamprey in a polluted environment through decreasing the duration of spermatozoid motility and possibly fertilization and hatching rates. Hence, contact to this metal could decrease the survival rate of this endangered species, especially during the reproduction.
Shadieh Mohammadi, Soheil Eagdari, Hadi Pourbagher, Ata Moloudi,
Volume 9, Issue 4 (11-2020)
Abstract
| In this study, the morphological variation of Oxynoemacheilus bergianus was studied in the different rivers of the Namak Lake and Caspian Sea basins using traditional morphometric method. For this purpose, a total of 76 specimens were collected from eight river systems and after fixation into 4% buffered formalin, transfered to the laboratory, a total of 31 morphological characteristics were measured using digital calipers. After standardization, the morphometric data were analyzed using multivariate analysis including principal component analysis (PCA), canonical variate analysis with p-value obtained from MANOVA (MANOVA/CVA) and cluster analysis (CA). The results showed significant differences in 24 traits between the studied populations (P<0.05), which anal fin depth and the ventral-anal fin distances were main discriminative ones. CVA analysis was able to separate the studied populations. Also, CA placed the Gharesu and Sefid populations in a clade and separate from other populations. The observed differences may be related to phenotype plasticity in response to environmental conditions. |
