Species identification using otolith morphometry of four gurnards (Family: Triglidae) from Edremit Bay (Aegean Sea)
TURKISH JOURNAL OF ZOOLOGY, vol.50, no.3, pp.160-171, 2026 (SCI-Expanded, Scopus, TRDizin)
- Publication Type: Article / Article
- Volume: 50 Issue: 3
- Publication Date: 2026
- Doi Number: 10.55730/1300-0179.3260
- Journal Name: TURKISH JOURNAL OF ZOOLOGY
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Geobase, TR DİZİN (ULAKBİM)
- Page Numbers: pp.160-171
- Keywords: Otolith, morphology, Triglidae, ShapeR, Edremit Bay, Aegean Sea
- Open Archive Collection: AVESIS Open Access Collection
- Dokuz Eylül University Affiliated: Yes
Abstract
Shape and size analyses of otoliths are widely considered appropriate tools for distinguishing between fish species and for assessing populations and stocks. The present study aims to distinguish four gurnard species collected from Edremit Bay (Aegean Sea) based on variations in their otolith shape morphology. A total of 60 specimens of Eutrigla gurnardus, 64 of Chelidonichthys lastoviza, 60 of Chelidonichthys lucerna, and 60 of Lepidotrigla cavillone were analyzed. No significant intraspecific differences were noted in the morphology of the left and right otoliths, and so only the left sagittal otoliths were subjected to further analysis. Otolith shape was quantified using wavelet coefficients generated via the ShapeR software package. In addition, otolith size indices, including length (OL), height (OH), perimeter (OP), and area (OA), were extracted from digital images, while shape descriptors such as form factor (FF), aspect ratio (AR), ellipticity (E), circularity (C), roundness (RD), and rectangularity (R), were measured for each species. Significant interspecific differences were observed in the otolith shape and size indices (p < 0.05), and mean otolith shapes generated using wavelet derived contours revealed obvious shape differences among the species. These findings were strongly supported by a canonical analysis of principal coordinates (CAP), with the first two axes together explaining 96.5% of the total variance (CAP1 = 84.7%, CAP2 = 11.8%). Overall, the results indicate that otolith shape analysis is a reliable tool for identifying gurnard species and provides a methodological baseline for future comparative studies in the Aegean Sea.