Identifying the species of the genus Alosa using the scales, wavelet and outline analyses

The species of the genus Alosa are very similar to each other in terms of morphology and cannot be identified easily. The present study used geometric morphometric techniques based on outline techniques on scales of the genus Alosa in the southern Caspian Sea, as the simple methods to identify fishes, on the specimens collected in the Southern Caspian Sea, i.e. Parehsar, Anzali, Roodsar and Tonekabon. Three species were found among the samples, i.e. A. braschnikowi, A. caspia and A. kessleri. Some scales from the ventral part of the body (keel) were removed and photographed. The wavelet analysis was performed using shapeR in the software R and canonical principal coordinate analysis were then applied on the scores produced by the wavelet analysis. Also, a Fourier analysis was performed on the outline of the scales followed by pairwise T2 Hotelling tests on the coefficients of the Fourier analysis. Our results indicated that there was a significant difference between A. braschnikowi and A. caspia in shape of the scales.