Age, growth and length–weight relationship of Coelorinchus caelorhincus (Risso, 1810) in the Adriatic Sea

Abstract

         Samples of Coelorinchus caelorhincus were collected by bottom trawl during MEDITS (“Mediterranean International Trawl Survey”) in June 2003 in the northern and central Adriatic Sea. A total of 175 specimens of C. caelorhincus were used for analysis, of which 90 were males, 84 females and 1 indeterminate. Pre-anal length (PAL) in males ranged between 39 and 77 mm (x̅=50.91±7.63 mm) and in females between 29 and 115 mm (x̅=55.86±16.3 mm). The length-weight relationship for the whole sample was W=0.0004PAL^2.65 (r²= 0.922) indicating negative allometric growth. The age structure of C. caelorhincus was determined from sagittal otolith readings. Maximum otolith length (LO) increased proportionally to fish length (LO=2.585+0.09PAL, r²=0.946). Age ranged from 2 to 8 years, with the majority of specimens being 3 (30%) and 4 (31%) years old. The von Bertalanffy growth parameters were: L_∞ = 128 mm, K = 0.105 year^-1 and t₀ = -1.277 year.