Morphological variations of common carp(Cyprinus carpio)by fixation and preservation in 10%formalin

Objective:To determine the effects of morphological characteristics of common carp(Cyprinus carpio)by fixation and preservation in 10%formalin.Methods:Fish samples were collected from the Research Center of Aquaculture of Barabadi Fazli martyr,Gorgan University of Agricultural Sciences and Natural Resources,Gorgan,Iran.After initial assay on morphological characters such as total length,standard length and head length,samples were fixed in 10%formalin for 12 weeks.After this period,samples were taken away from the formalin and the morphological characteristics and evaluation of color features were assayed once again.Results:The results indicated that shrinkage was usual in all the specimens and changes in body and fins color were clear and their color was opaque.Formalin preservation is usually causing a reduction in the length of fishes.Conclusions:Different rates of change in body length and color of preserved sample are observed after a standard period of preservation in different preservatives and it can be suggested that the decrease of color intensity in fixed samples in formalin does not have inhibition effects in color identification keys.