Age determination of John's Snapper (Lutjanus johnii) using Otolith sections

Abstract

The age structure of John's Snapper (Lutjanus johnii) in Hormozgan waters, south Iran was studied. We conducted monthly sampling starting in May 1996 and ending in July 1997. Totally, 613 fish specimens were collected, of which 567 and 308 specimens were aged based on whole and sectioned otoliths respectively. The snappers were found to be aged from 1 to 17 years old. Results showed that each year only one pair of opaque and translucent zones was formed. Age determination based on the two methods was significantly different especially in the fish aged 1 to 6 years (P0.05). Age-length relationship of the species based on sectioned otolith reading and total fish length using the least squares method was obtained as Lt = 89(1-e-0.165(t+1.476)). Also, the length-weight relationship for the fish was determined as W=(4x10-5)xL2.8214.