In the study, it was aimed to determine the morphometric measurements of Siganus rivulatus (Forsskål & Niebuhr,
1775) sampled from Mersin Bay in February 2021. The average value of some morphometric measurements of fish
from Mersin Bay (n=196) were found that the total length 17.87 ± 3.11 cm, standard length 13.88 ± 1.96 cm, fork
length 17.06 ± 1.35 cm, head length 3.60 ± 0.76 cm, eye diameter 1.08 ± 0.23 cm, interorbital distance 1.60 ± 0.34
cm, body width 2.32 ± 0.48 cm, dorsal fin base length 10.45 ± 2.19 cm, anal fin base length 6.26 ± 1.31 cm, pectoral
fin length 2.56 ± 0.53 cm and caudal peduncle height 0.78 ± 0.16 cm. The total length-weight relationship of the
species was determined as W = 0.008xTL3.16 (r2=0.973) and it was found that the fish showed positive allometric
growth.