Morphology of the sagittal otolith in Liza aurata (Risso, 1810) from coastal habitats of Caspian Sea southern basin

Document Type : Research Paper

Authors

1 Shahid Bahonar University of Kerman

2 Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman

Abstract

To do this objective, the otolith morphology and the relationships between fish length and weight with otolith dimension of Liza aurata (Risso, 1810) populations in coastal habitats of the Caspian Sea southern basin were studied. The specimens were sampled from four coastal populations including Nekah, Sorkhrud, Chalus and Bandar Anzali, then fixed in 75% alcohol and transferred to the laboratory for the otolith preparation. The left otoliths were extracted from adult specimens and photographed by camera connected to stereomicroscope. According to the results, otolith diameter ranges was 2.9 to 3.3% Standard Length (SL). Liner regression between fish length and otolith length was TL=4.6042.OL - 3.5555, R2=0.8492 and regression model between fish length and otolith weight was Ow=19.389.TL0.0129, R2=0.755. The results indicated that there was positive relationship between fish body length and otolith dimensions. The results showed that general shapes of the otoliths in studied populations were mostly rectangular to oblong with irregular and also margins have indentations in ventral and dorsal rims. The antirostrum was absent. The ostium was opened and funnel-like in anterior part of the sulcus, while it was closed and tubular in the posterior end and positioned in posterior ventral corner. Since the most important otolith characters that used to identify the Mugilidae species are the position of the sulcus, therefore it can be concluded that this character probably plays an important role in among population variations.

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