Target Strength and swimbladder morphology of Mueller's pearlside (Maurolicus muelleri).

摘要: In the last few years, there has been increasing interest in commercial exploitation of mesopelagic fish and a trawl-acoustic methodology recommended to make estimates abundance these resources. This study provides relevant information on scattering properties key species Bay Biscay, Mueller’s pearlside (Maurolicus muelleri), necessary convert acoustic density into numerical abundance. The target strength (TS) was estimated for first time at five frequencies commonly used surveys. A high-density filter applied reduce bias derived from overlapping echoes erroneously assigned single targets. Its relationship with length (b20) also determined (−65.9 ± 2, −69.2 ± 3, −69.2 ± 2, −69.5 ± 2.5 −71.5 ± 2.5 dB 18, 38, 70, 120 200 kHz, respectively). Biomass Biscay during four years (2014–2017) are given using 38 kHz frequency. Morphological measurements swimbladder were obtained soft X-ray images backscattering simulation gas-filled ellipsoid. Pearlside is physoclist species, which means that they can compensate swimbadder volume against pressure changes. However, best fit between model experimental data showed lose capacity trawling process, when affected by Boyle’s law.