Using Scanning Electron Microscopy and Length-Otolith Size Relationship for Otolith Morphological Description of Capoeta banarescui Turan et al., 2006 and Squalius cephalus (L., 1758) (Actinopterygii: Cyprinidae) from Turkey

Abstract

The aims of this study were to: 1) identify unstudied otolith morphometry and 2) determine the relationship between otolith size-fish length in Capoeta banarescui and Squalius cephalus. A total of 346 samples were caught from the Lower Melet River and camlidere Dam Lake. Fork length (FL) of the samples was measured. Asteriscus otolith pairs were removed from each individual. Otolith variables such as weight, length, width, area, and perimeter were measured for undamaged and clean otolith pairs. Differences between right and left otoliths were tested using a paired t-test. The difference between right and left otoliths was not statistically significant (P>0.05) for otolith weight (WO), length (OL) and width (OW) measurements for both species. Shape indices, such as form factor, roundness, aspect ratio, circularity, rectangularity and ellipticity, were calculated using otolith measurements. Additionally, otolith morphologic features were examined using Scanning Electron Microscopy (SEM). According to SEM, otolith surface and margin were different for C. banarescui and S. cephalus. The highest correlation of fork length-otolith dimensions were calculated as OL = 0.1179FL+0.5389 (r(2)=0.88) for C. banarescui and WO = 0.0005FL-0.0071 (r(2)=0.81) for S. cephalus. Otolith length was more suitable than otolith weight for predicting of C. banarescui, while otolith weight was the best predictor of S. cephalus.