Metabolic rates in Atlantic bluefin tuna larvae: first data and methodological challenges

Blanco, Edurne; Reglero, Patricia; Ortega-García, Aurelio; Folkvord, Arild; de-la-Gándara, Fernando; Hernández de Rojas, Alma; Moyano, M.

Metabolic rates in Atlantic bluefin tuna larvae: first data and methodological challenges

Blanco, Edurne,Reglero, Patricia,Ortega-García, Aurelio,Folkvord, Arild,de-la-Gándara, Fernando,Hernández-de-Rojas, Alma,Moyano, M.

Repository: digital.csic.es
Language: en

Abstract

Atlantic bluefin tuna is an emblematic scombrid species, but many physiological aspects during the larval stages are still unknown. The mechanisms of how fish larvae balance growth and activity are of great interest since metabolic costs are very high compared to juveniles and adults. However, there is a lack of information about metabolic costs in scombrid larvae. This lack of data is probably related to the challenges associated to larval handling before and during respirometry trials. In this study for the first time, we: i) estimate the relationship between routine metabolic rate and the larval dry weight (mass scaling exponent) at 26°C, ii) measure metabolism under light and darkness and iii) explore the influence of nutritional status (RNA:DNA ratio) on the inter-individual variability in metabolic rates. The relationship between metabolism and size (ranging from 0.6 to 23 mg) was near isometric (slope, b=0.99), in contrast to the allometric relationship observed in most species (b=0.87). Our results show no significant differences in oxygen consumption under light and darkness. A possible regulation (decrease) of their swimming activity with the consequent decrease in the oxygen consumption in light situations is discussed. Nutritional condition did not explain the inter-individual differences in oxygen consumption. This study first reports metabolic rates of Atlantic bluefin tuna larvae and discusses the challenges of performing bioenergetics studies with early life stages of Scombrids.

Full text

FROTH:6 METABOLIC RATES IN ATLANTIC BLUEFIN TUNA LARVAE: FIRST DATA AND METHODOLOGICAL CHALLENGES Edu ne Blanco, Pa icia Regle o, Au elio O ega, A ild Folk o d, Fe nando de la Gánda a, Alma He nández de Rojas, Ma a Moyano [email p o ec ed] A lan ic blue in una is an emblema ic scomb id species, bu many physiological aspec s du ing he la al s ages a e s ill unknown. The mechanisms o how ish la ae balance g ow h and ac i i y a e o g ea in e es since me abolic cos s a e e y high compa ed o ju eniles and adul s. Howe e , he e is a lack o in o ma ion abou me abolic cos s in scomb id la ae. This lack o da a is p obably ela ed o he challenges associa ed o la al handling be o e and du ing espi ome y ials. In his s udy o he i s ime, we: i) es ima e he ela ionship be ween ou ine me abolic a e and he la al d y weigh (mass scaling exponen ) a 26°C, ii) measu e me abolism unde ligh and da kness and iii) explo e he in luence o nu i ional s a us (RNA:DNA a io) on he in e -indi idual a iabili y in me abolic a es. The ela ionship be ween me abolism and size ( anging om 0.6 o 23 mg) was nea isome ic (slope, b=0.99), in con as o he allome ic ela ionship obse ed in mos species (b=0.87). Ou esul s show no signi ican di e ences in oxygen consump ion unde ligh and da kness. A possible egula ion (dec ease) o hei swimming ac i i y wi h he consequen dec ease in he oxygen consump ion in ligh si ua ions is discussed. Nu i ional condi ion did no explain he in e -indi idual di e ences in oxygen consump ion. This s udy i s epo s me abolic a es o A lan ic blue in una la ae and discusses he challenges o pe o ming bioene ge ics s udies wi h ea ly li e s ages o Scomb ids.