جستجوی مقالات مرتبط با کلیدواژه « اتولیت » در نشریات گروه « شیلات »

To provide more morphological data of I. persa, in this study, morphological characteristics along with scales and otolith were studied. Fish samples were collected from Khorgo spring and transferred to the laboratory. Fish were classified into three class sizes based on standard length. Based on the results, the size of the first class was different in 12 relative traits but did not show a significant difference in the number of anal and dorsal fin rays. The general shape of otoliths was trapezoidal, and antistrostrom was not developed in small fish (SCI, SCII), while rostrum was more developed in larger fish than antistrostrum. Also, the ventral edge of the otolith was wider and serrated with age. Examination of the structure of the scales showed that in the first class, the relative length of the scales (JSL) was significantly different. Based on this study, it can be concluded that in addition to past documented molecular data, some morphological characteristics of fish bodies, otoliths, and scales can also be used to identify native Iranian cichlid fish. It was also found that phenotypic characteristics in this species show degrees of ontogenetic diversity (dependent on fish growth and length) that should be examined in detail.

The study was performed on the shape and morphology of otolith Grammoplites suppositus (Troschel, 1840) in Bushehr and Hormozgan waters of the Persian Gulf. 157 specimens (86 from Hormozgan and 72 from Bushehr) were collected as trawl bycatch. All the specimens are killed and fixed in 70% alcohol. After obtaining otolith, its shape indices include: form factor, roundness, circularity, rectangularity, ellipticity, otolith size index, otolith longitude index were examined by Image Measurement software. Then all the measuring indexes were analyses by Univariate and Multivariate analysis. In the analysis of otolith shape of the two regions, a significant difference was observed in most of the studied parameters. Also, differential population analysis such as MANOVA / CVA showed the existence of two separate populations in the study areas.

This study aimed to a comparison of morphometric characteristics of otolith in Epinephelus coioides (88 specimens), Epinephelus latifasciatus (71 specimens), Epinephelus bleekeri (69 specimens) and Epinephelus diacanthus (145 specimens) in coral reefs of the Persian Gulf and Oman Sea. Species were collected during 2014 - 2015. All fish were identified and their otoliths were extracted to verify them. Investigation of otolith morphometric characteristics (length, breadth, weight, perimeter and, area) was conducted. Data indicate a high correlation between otolith length and otolith weight, fork length, and otolith length and between fish length and weight (R2>0.854), the highest correlation was observed in E. diacanthus (R2= 0.894). Also, the results indicate that in the studied species, biometric differences are observed along with the difference in the shape of the otolith, according to the results, the highest length, the highest weight, the highest area and the highest perimeter of otolith were related to the E. diacanthus with mean total length of 26± 3.2 cm and the average weight of 1357.27 ± 104.27 g, and the highest otolith width was related to the E. coioides with an average total length of 38 ± 1.8 cm and the mean weight of 1289.54 ± 124.42 g. This study indicated that the relationships between sagitta and morphometric characteristics of various species are different and can be used as an indicator in species identification.