فهرست مطالب
International Journal of Aquatic Biology
Volume:6 Issue: 6, Dec 2018
- تاریخ انتشار: 1398/01/30
- تعداد عناوین: 6
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Pages 296-302Gene promoters located at the 5′ end of genes are instrumental in regulating the gene expression in a ubiquitous or tissue specific manner. The objective of the study was to identify, clone and characterize promoters involved in gene expression in specific tissues such as the blood and blood vessel of Zebrafish. Three genes, known to express in the blood and blood vessel lineage in Zebrafish, were selected viz. Pak2a, Rac1 and Cdc42. Approximately 800 bp of putative promoter region of Pak2a and 826 bp putative promoter region of cdc42 were cloned into plasmid vectors. This putative promoter did not show any expression in Zebrafish embryos. However, approximately 716 bp of putative promoter region of Rac1 showed Red Fluorescent Protein expression. While study Cmlc2 was used as a positive control.Keywords: Gene Expression, Promoters, Red Fluorescent Protein, Zebrafish
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Pages 303-306In the course of evolution, phagotrophic euglenoids developed before the phototrophic species. Most phagotrophic euglenoids have a robust feeding apparatus. Members of the algal genus Peranema are able to eat a wide variety of living organisms that have little or no mobility, such as other unicellular algae and live yeasts. Stabilization ponds are artificial environments rich in organic matter, nutrients and microorganisms, and are therefore suitable environments for growing species of Euglenophyta. This contribution records, through photographs and videos, the operation of the feeding apparatus of Peranema collected in a wastewater stabilization pond. The mean pheophytin content of the water was higher than the mean chlorophyll a content, which indicates a non-ideal environment for the growth of microalgae. Thus, Peranema can be used as a bioindicator of the quality of wastewater stabilization pond. The operation of the feeding apparatus of Peranema sp. and the strategy for phagocytizing plastids of Lepocinclis sp. are described.Keywords: Euglenophyta, Peranema, Phagotrophic, Pheophytin
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Pages 307-313The objective of the present study was to estimate the population parameters, including length-weight relationship (LWR), condition factor (KF), relative condition factor (Kn), age, growth, and mortality of Capoeta damascina in the Azad Dam and Komasi River in the Kurdistan Province, Iran. Total length and weight were 51-350 (180.6±68.63) mm and W: 2.5-465 (93.3±110.89) g in the river and 120-260 (191.5±30.76) mm and 14.7-216 (75.9±39.89) g in the dam Lake and river, respectively. The length-weight regression was W=0.0122×FL2.9338. The sex ratio (M:F) was 1:0.47, for adult C. damascina which differed significantly from the expected 1:1 (P<0.001). The von Bertalanffy growth parameters were estimated as L∞ = 373.3 mm, K = 0.17 yr-1 and t0 = -0.58 yr. The instantaneous coefficient of natural mortality was estimated as 0.36 yr-1. The average KF values were 1.13±0.14 and 0.98±0.18, and Kn were 1.11±0.12 and 0.98±0.18, in the river and the lake, respectively. In conclusion, C. damascina showed an isometric growth pattern, which the rapid growth is occurred during the two first years of life. The Kn showed that the fish were at suitable welfare conditions in the Azad Dam.Keywords: Growth parameters, Length-weight relationship, Condition factor, Population
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Pages 314-320In the present study, susceptibility of Persian sturgeon, Acipenser persicus, to un-ionized ammonia (UIA) was studied. Fish with an average weight of 5.52±0.45 g were exposed to different concentrations of un-ionized ammonia (UIA) to determine median lethal concentration (96-h-LC50). The fish were exposed to six different concentrations of UIA (control, 0.16, 0.31, 0.62, 0.94 and 1.25 mg/l UIA). The control group was not challenged with ammonia (0.0008 mg/l UIA). The results showed that the 96-h-LC50 of UIA in Persian sturgeon was 0.46 mg/l. According to 96-h-LC50,mid-term exposure to sub-lethal UIA was examined. In the chronic examination, the fish were exposed to different levels of sub-lethal ammonia; control (0.0008 mg/l UIA), 10% of LC50 (0.05 mg/l UIA), 5% of LC50 (0.025 mg/l UIA) and 1% of LC50 (0.005 mg/l UIA) for 30 days. Final length, final weight, weight gain, specific growth rate, daily weight gain and body weigh index decreased significantly in the fish exposed to 0.05 and 0.025 mg/l UIA. According to the results, conversion ratio and condition factor indices were higher in the fish exposed to 0.005 mg/l UIA and control group compared with the fish exposed to 0.05 and 0.025 mg/l UIA.Keywords: Sturgeon, Ammonia, LC50, Growth performance, Toxicity
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Pages 321-329The present study aimed to assess the ovarian tissue structure and plasma levels of the hypophysial-gonadal hormones, including 17-β estradiol, progesterone, GTH-I and GTH-II of the Arabian carpet shark, Chiloscyllium arabicum inhabiting the Persian Gulf in spring (April to July) and autumn (August to December). In this regards, a total of 60 C. arabicum female specimens were collected from the Bahrakan Port, in the north of the Persian Gulf. Fish were bleed after euthanization and biometrical characters and levels of 17-β estradiol, progesterone, GTH-I and GTH-II were measured. Fish were then dissected and samples were taken from the ovary and fixed in Bruin’s solution for 48 hrs. Histological sections were prepared using routine histological techniques and stained with hematoxylin and eosin. Based on the results, four different developmental stages were observed in the ovary in spring, including stage I, stage II (primary oogenesis), stage III (mediate oogenesis), and stage IV (final oogenesis). However, only three first stages were detected in autumn samples. The plasma levels of the studied hormones were higher in spring. Based on the results, spring (especially mid-April to mid-July) is the reproduction season of C. arabicum in the Persian Gulf.Keywords: Carpet shark, Ovary, 17-? estradiol, Progesterone, Gonadotropin
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Pages 330-338Decades since restocking program of the vulnerable native Cyprinus carpio in the southern Caspian Sea, the cultured stocks in hatcheries have created new challenge to protect the native population. Releasing the cultured common carp in natural water-bodies caused an uncertainty about originality of the carp broodstocks within the restocking program. To clarify that how the selective breeding with aquaculture purpose could change the body shape with aiming to prepare an identification key for the indigenous and cultured stocks, a landmark based morphological characteristics of these stocks from the Anzali Wetland and a hatchery were analyzed. Univariate analysis of variance of 100 adult specimens collected during the non-reproductive season were observed in 62 morphometric characters out of 78 (P<0.05). Principle component analyze (PCA) of morphometric characteristic showed a high differentiation between these stocks. In morphometric traits, linear discriminate function analysis (DFA), the overall assignments of individuals into their original groups between stocks were 100%. The PCA and DFA showed a morphological segregation of the studied stocks based on the characters head shape, pre-dorsal, pre-pelvic and pre-anal distances, caudal peduncle depth, dorsal fin and ventral fin origins, body depth and caudal fin origin. The results showed stocks represent two distinct morphological forms of C. carpio that had high morphometric differentiation. The results can be useful as baseline information on the native stock for conservational policy. To protect the vulnerable population, using wild native broodstocks in the restocking program is strongly recommended.Keywords: Morphology, Stock Structure, Caspian Sea, Restocking program