Abstract:The beak length and its relationship with mantle length, body weight as well as age were studied based on 103 beaks and 60 statoliths specimen of the purleback flying squid Sthenoeuthis oualaniensis which were collected during jigging surveys in northwest Indian Ocean from October to December in 2004 and in April of 2005. The results indicated that the beak dimensions were best described by linear functions with mantle length but showed positive exponential correlation with body weight. With the squid ontogenetic growth, size of each part of the beak became larger. Hood and crest grew faster but rostrum and wing grew slower. Hood and crest of the upper beak grew faster than that of the lower beak. Dimensions of each part were best described by linear functions with age except for the wing of upper beak which fitted exponential function. The results provided basic data for the resources estimation of S.oualaniensis.
