Presence of abnormal otoliths in hallucinogenic fish and their comparison with normal otoliths using light and scanning electron digital imaging

Abstract The otolith organs located in the inner ear of the fish are responsible for vital activities such as balance and hearing. Abnormalities in these organs can adversely affect the vital activities of the fish species. The main purpose of the study is to analyze the abnormalities in the otoliths of Sarpa salpa , known as the hallucinogenic fish. For that, 372 individuals of S. salpa are collected from the North Aegean Sea. As a result of the abnormality analyses in S. salpa otoliths, anomalies were detected such as various prominence structures on the surface of the otolith caused by accumulation and a more transparent appearance due to the different crystal structures in some parts of the otolith. These abnormalities were found in the left and/or right otoliths of male and female individuals in different total lengths. The percentage of individuals with abnormal otoliths of S. salpa is calculated as 52.42%. It was determined that there are statistical differences between the left and right otolith measurements of male and female individuals with abnormal and normal otoliths( p < 0.05). There is no relationship between the percentage of individuals showing abnormality and total length and sex. The current study presents for the first time abnormal otolith information on left and right otoliths in male and female S. salpa. It is thought that abnormalities in hallucinogenic fish otoliths could be related to genetic predisposition as well as stress due to nutritional preference, pollutants, and environmental factors. Research Highlights The presence of abnormalities in the otoliths of Sarpa salpa , a hallucinogenic fish, was revealed for the first time. Abnormalities in the otoliths of S. salpa were identified, such as the presence of various prominence structures on the otolith's surface, loss of parts as well as a more transparent appearance in the outlines or surface of the otolith. Normal and abnormal otoliths of female and male hallucinogenic fish from different size groups were examined using light and scanning electron microscopy. Abnormality detected in the otoliths of hallucinogenic fish is not related to the gender and size of the fish.