علوم زیستی دریا
narges badri; Narges Amrollahi biuki; Mohammad Sharif Ranjbar
Abstract
The LC50-96h test paradigm is used to measure the susceptibility and survival potential of organisms exposed to particular toxic substances, such as heavy metals. In this study, the statically acute toxicity of Pb on hermit crab D. avarus was determined according to standard methods O.E.C.D in 96h. 84 ...
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The LC50-96h test paradigm is used to measure the susceptibility and survival potential of organisms exposed to particular toxic substances, such as heavy metals. In this study, the statically acute toxicity of Pb on hermit crab D. avarus was determined according to standard methods O.E.C.D in 96h. 84 individual hermit crab with 0.19±.0.01 g weight average were used in five different treatments (75, 100, 150, 175, 200 microgram per liter of lead) with three replicates and a control treatment (15 hermit crab per in each treatment). The effective physical and chemical parameters of water including pH, total hardness, dissolved oxygen and temperature were controlled throughout the experiment. Finelly, the rate of the acute toxicity (LC50 96h) was determined to be 184.045 µg/l by using the statistic method Probity analysis. Furthermore, the rates of LC10, LC50, LC90 (24, 48, 72 and 96h) were calculated. Results indicate that when the experiment time is extended, lower concentration of Pb is leading to mortality in hermit crab D. avarus. The percentage of mortality increased with increasing duration of exposure of crab to different amounts of lead concentration. The behavioral changes observed in hermit crabs D. avarus in the experiment period included an imbalance in walking, reduced activity and movement, slow motion, no irritability and also color change of the abdomen.
علوم زیستی دریا
Mousa Keshavarz; Ehsan Kamrani; Narges Amrollahi Biuki; Hossein Zamani
Abstract
Some of valuable species of Persian Gulf, such as sea urchins, are accounted less scientific studies due to the lack of any position in the local food baskets. Therefore, this survey is investigated the biometrical parameters of sea urchin Echinometra mathaei for a period of seven months (March– ...
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Some of valuable species of Persian Gulf, such as sea urchins, are accounted less scientific studies due to the lack of any position in the local food baskets. Therefore, this survey is investigated the biometrical parameters of sea urchin Echinometra mathaei for a period of seven months (March– September, 2014) in the intertidal zone of Lengeh Port (26˚32ʹ28 ̋N, 54˚52ʹ29 ̋̋ E). Random samples were collected monthly during spring tides and transferred alive to the laboratory and then the dissection and the separation of different parts of the body were started. Each part of the body length and weight was measured. By a mathematical method the volume of samples was calculated as an elliptical object. This study illustrated the largest and smallest sample were 0.07 and 103.77 grams, respectively. Results showed that the relationships between Total wet weight and Test Diameter (Total Wet Weight = 0.0053 Test Diameter2.3933), Total Wet Weight and Height (Total Wet Weight = 0.0122 Height2.5872) and Total Wet Weight and Volume (Total Wet Weight= 0.0071 Volume0.8706). The correlation coefficient between volume and total wet weight of samples was r=0.94 which shows the accuracy of Disk method. On the other hand, the HDR index was more in compared with the HWR index and it illustrates larger values of Test Diameter in compare with Height. Statical analyses prove that higher values of DWR in compared with HWR are reasonable and accurate in both sexes.