Effects of progressive hypoxia on oxygen uptake in juveniles of the Peruvian scallop, Argopecten purpuratus (Lamarck, 1819) - Université de Bretagne Occidentale Accéder directement au contenu
Article Dans Une Revue Aquaculture Année : 2016

Effects of progressive hypoxia on oxygen uptake in juveniles of the Peruvian scallop, Argopecten purpuratus (Lamarck, 1819)

Résumé

A field survey performed in Paracas Bay (Peru), a major scallop culture area, showed that the Peruvian scallop, Argopecten purpu-ratus, periodically faces severe hypoxic events. Oxygen uptake rate (VO2) of A. purpuratus juveniles facing progressive decrease of environmental oxygen saturation (from 100% to 5%) was measured at two contrasting temperatures ("normal condition" = 16°C and "warm condition" = 25°C). In normoxia, (oxygen saturation >70%) average VO2 was significantly (p < 0.001) higher in warm condition (0.20 ±0.004 mgO 2 ind −1 h −1) than in normal condition (0.12 ±0.007 mgO 2 ind −1 h −1). The shape of the VO2 response curve during increasing hypoxic conditions was evaluated using a segmented linear regression. The break points between linear segments allowed estimating the oxygen critical points (PcO2 , oxygen saturation units), while the slopes of the various segments was used to assess the VO2 regulatory capacity. In both temperature conditions at oxygen saturation lower than PcO2 , VO2 was a fourth of the values recorded in normoxic condition. This trend was more pronounced in the warm condition. Paradoxically, the estimated PcO2 was lower in warm condition (21.4% ±0.7) compared to the normal condition (24.4% ±1.9). However, the study of the slopes at oxygen saturations higher than PcO2 revealed that A. purpuratus can regulate its respiratory rate similarly and efficiently at both 16 and 25°C. Moreover, for VO2 above PcO2 , the estimated Q10 between normal and warm conditions was 1.78 (Arrhenius temperature = 4983 K), highlighting a moderate effect of temperature on VO2. These results reflect the adaptive capacity of this species to the changing environment along the Peruvian-Chilean coasts influenced by upwelling system and ENSO events. However, results from this study indicate that, at least during some periods, A. purpuratus spend more than 70% of its time exposed to hypoxic conditions below the estimated PcO2. Such conditions could have negative consequences on the species metabolism and harm the performance of A. purpuratus culture.
Fichier principal
Vignette du fichier
Aqua_PcO2_AguirreVelarde.pdf (129.89 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Loading...

Dates et versions

hal-01282771 , version 1 (04-03-2016)

Identifiants

Citer

Arturo Aguirre-Velarde, Fred Jean, Gérard Thouzeau, Jonathan Flye-Sainte-Marie. Effects of progressive hypoxia on oxygen uptake in juveniles of the Peruvian scallop, Argopecten purpuratus (Lamarck, 1819). Aquaculture, 2016, 451, pp.385-389. ⟨10.1016/j.aquaculture.2015.07.030⟩. ⟨hal-01282771⟩
275 Consultations
488 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More