AGE DETERMINATION OF TRACHINOTUS OVATUS ( L.) BASED ON OTOLITH WEIGHT

AGE DETERMINATION OF TRACHINOTUS OVATUS ( L.) BASED

ON OTOLITH WEIGHT
By
M. H. MOURAD*
*National Institute ofOceanography & Fisheries, Alexandria – Egypt
Key words: Age determination; Otolith weight; Trachinotus ovatus (L.).
ABSTRACT
Age determination of fish, from a population having a.·.··
considerable variation in size at age, has been investigated using the
relationship between otolith weight and fish length, which has been
described by many authors to be influenced by growth rate. In such a
population ofTrachinotus ovtaus (L.), an index ofage can be obtained
for individual fish by estimating the equivalent otolith weight at a
particular fish length (L) nd he ppropriate alue f odal ength
(L”J, using the otolith weight – fish length relationship determinedfor
each age group. This index ofage can be calculatedfrom the formula: