Morphological characteristics of lapillus and aging of Plicofollis dussumieri (Ruppell, ۱۸۳۷) from Oman Sea

In this paper age determination and morphological characteristics of blacktip catfish, Plicofollis dussumieri, from Oman Sea were evaluated. A total of ۱۳۲ fish specimens were collected from fishing trawlers or landings from March ۲۰۱۱ to July ۲۰۱۲, with minimum and maximum of ۲۴۵ mm, ۱۹۵ g and ۷۶۷ mm, ۵۸۰۱ g, respectively. Maximum life span was ۱۲ years for the length range of ۲۴۵ – ۷۶۷ mm FL, while total body weight (BW) ranged between ۱۹۵ and ۵۸۰۱ g and the resultant equation was: W = ۰.۰۴۰ L۲.۸۲۷۵ (R۲ = ۰.۹۹). High correlation coefficient value found between age and FL was R= ۰.۹۷ and for age-BW was ۰.۹۴. This value for otolith weight and BW was estimated to be ۰.۹۱ and showing that there were significant correlations between measured parameters. Lapillus otolith in blacktip catfish is the biggest otolith among most teleostei fishes, also the Sagitta is the biggest. Lapillus of this species is round, robust, onion-like and without sulcus curve, with no obvious growth increments in rostrum and antirostrum zones. In ventral side Gibbus maculae is concave having prominentia marginalis in anterior and basal line in posterior parts.