Shima Bakhshalizadeh; Ali Bani; Shahram Abdolmalaki & Jesus T. Ponce-Palafox

The morphology of the sagittal otolith of Great sturgeon (Huso huso), Persian sturgeon (Acipenser persicus) and starry sturgeon (Acipenser stellatus) species from the Iranian waters of the Caspian Sea were studied. Three otolith measurements and three shape indices were recorded from 90 sturgeon specimens. Fish biometry traits were measured and relationship between sagittal otolith length (OL)-total length (TL), and sagittal otolith weight (WO)-body weight of fish (BW) were estimated. Sagittal otolith has a triangle shape with irregular edges in great sturgeon, elongate triangle with smooth surfaces in Persian sturgeon, and relatively circular with smooth surface in starry sturgeon. The ratio of the WO/BW in starry sturgeon was significantly higher ( P <0.05) than great sturgeon and Persian sturgeon. There is a direct proportional relationship between BW and WO in Persian sturgeon (r2=0.7), great sturgeon (r2=0.9) and starry sturgeon (r2=0.9). Regression line slope for these relationships in starry sturgeon were less than Persian sturgeon and great sturgeon. Furtheremore, there is significant linear regression between OL-TL. Results showed that it is possible to identify Caspian sturgeon species based on body morphometry and sagittal otolith characteristics.

KEY WORDS: Otolith shape; Huso huso; Acipenser persicus; A. stellatus.

BAKHSHALIZADEH, S.; BANI, A.;ABDOLMALAKI, S. & PONCE-PALAFOX, J. T. The sagittal otolith morphology observations of sturgeon species in Iranian waters of the Caspian Sea. Int. J. Morphol., 36(2):523-526, 2018.