Feeding ecology of blue whiting (Micromesistius poutassou) larvae in the Northwestern Mediterranean Sea

• Main Authors: Mir-Arguimbau, Joan, Olivar, M. Pilar, Navarro, Joan, Raya, Vanesa, Sabatés, Ana
• Format: Still Image
• Language: unknown
• Published: 2019
• Subjects: North Atlantic
• Online Access: http://hdl.handle.net/10261/197518; https://doi.org/10.13140/RG.2.2.14641.43364

43 Annual Larval Fish Conference, 21-24 May 2019, Palma, Balearic Islands.-- 1 page, 4 figures Blue whiting, Micromesistius poutassou, is a gadoid widely distributed in the North-Atlantic Ocean and Mediterranean Sea. The Mediterranean population is considered isolated from the Atlantic Ocean, and in the northern Catalan coast (NW Mediterranean Sea) it is a species of high commercial interest. In this area, fluctuations in the abundance of blue whiting have been related to interannual variations in winter hydrodynamics. These, in turn, lead to fluctuations in primary production that, may then determine changes the survival of early life stages. For this reason, understanding food web interactions during the larval stage is pivotal to predict the success of recruitment to adult fish populations. In order to approach this subject, we studied the trophic ecology of blue whiting larvae by combining stomach content and stable isotopic analyses, in the Catalan coast, during two consecutive winters of contrasted environmental conditions. The specific aims were: (1) to analyse the diet composition of blue whiting larvae; (2) to assess the likely interannual differences in diet in relation to winter conditions and (3) to examine the trophic structure and relationships among blue whiting larvae and the biomass-dominant plankton items. The stomach content of blue whiting larvae (2-34 mm SL), collected day and night, was analysed and prey were measured and identified to the lowest taxon possible. Prey carbon content was estimated from size data using taxon-specific allometric equations. The stable isotope analyses were conducted in blue whiting larvae at different ages (preflexion, flexion and postflexion stages), in fractionated plankton samples, and in the most abundant planktonic groups Peer Reviewed