Animal physiology
Mousa Keshavarz; Jamileh Pazooki
Abstract
Chitin is found in the exoskeleton of many invertebrates, the cell wall of most fungi and some algae which is converted into chitosan through some reactions. Chitosan is a combined polymer of glucosamine and N-acetylglucosamine, linked by 1 and 4 glycosidic bonds. In this article, the structural and ...
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Chitin is found in the exoskeleton of many invertebrates, the cell wall of most fungi and some algae which is converted into chitosan through some reactions. Chitosan is a combined polymer of glucosamine and N-acetylglucosamine, linked by 1 and 4 glycosidic bonds. In this article, the structural and physicochemical characteristics of chitosan extracted from the shell wastes of of shrimp species Penaeus merguiensis and squid shells Sepia pharaonis have been compared. Samples were collected from the coast of Bandar Abbas and in order to extract chitin and chitosan, their physicochemical characteristics were measured using FTIR, XRD, and SEM methods. The molecular weight of chitosan samples obtained from the shell of Banana prawn and Pharaoh Cuttlefish was calculated as 26,000 and 14,000 kDa, respectively, and the deacetylation percentage of chitosan in P. merguiensis and S. pharaonis was calculated as 66% and 30.5%, respectively. The findings showed that micrographs of the shrimp shell are heterogeneous and non-flat and in the form of broken rod-shaped structures, and the surface morphology of chitosan prepared from Cuttlefish shell showed a smooth surface with few larger and stone-like structures on it. In recent years, the scientific community has increased its attention to chitosan products derived from marine wastes for this biopolymer, and this study indicated that, given the large volume of marine waste produced in Bandar Abbas, and taking into account environmental considerations, efforts were made to extract chitosan derivatives from marine waste.
Musa Keshavarz; Maryam Soyuf Jahromi
Volume 6, Issue 1 , May 2017, , Pages 121-132
Abstract
Sea urchin as a bioerosion, is an effective factors on coral reef ecosystems which the observable biometry of urchin and its relationship with the jaw is important. Therefore, within this survey, sea urchin Echinometra mathaei were examined for summertime (July–September, 2014) between the intertidal ...
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Sea urchin as a bioerosion, is an effective factors on coral reef ecosystems which the observable biometry of urchin and its relationship with the jaw is important. Therefore, within this survey, sea urchin Echinometra mathaei were examined for summertime (July–September, 2014) between the intertidal areas of Dayyer Port (51˚53’49.39ʼ’E, 27˚50ʼ3.57’’N), Iran. A total of 91 individuals lively transferred to a lab. Total wet weight was weighted by a digital scale and the test height and diameters and the jaw length was measured by caliper (0.01 precision). The relationships between heights and diameters with weights were calculated according to indices and the relationships between the jaw lengths and test height and diameter were achieved. The results illustrated that the relationship between test height to its diameter (HDR index) is independent of test diameter (the slop near to zero) and therefore, there is a direct relationship between test height and diameter (a=0.47). Although the highest values of test height and spin length refer to males, but females achieved bigger values of test diameter, height and thickness (mean test height, diameter and thickness of females were 24.13±3.52 mm, 44.93±5.71 mm, 0.83±0.16 mm; and males: 21.22±6.82 mm, 37.67±12.27 mm, and 0.73±0.20 mm, respectively). The test diameter and weight of immature samples were less than 20 mm and 6.66 gr, respectively where can be as a primary criterion of Echinometra mathaei sexual maturity. Two indices HWR and DWR of both females and males had obvious differences with total samples, which also can be related to immature samples. Moreover, the jaw length was half of height (a=0.49, r=0.87) and a quarter of diameter (a=0.25, r=0.89). Results also illustrated well that larger samples had longer jaws that it could help identifying higher erosive samples.
