Linking stocking densities and feeding strategies with social and individual stress responses on gilthead seabream (Sparus aurata)

PHYSIOLOGY & BEHAVIOR

卷:213

Article

Arechavala-Lopez, Pablo^1,2  Nazzaro-Alvarez, Joan³  Jardi-Pons, Andrea³  Reig, Lourdes⁴  Carella, Francesca⁵  Carrasson, Maite⁶  Roque, Ana³ 

[1] Mediterranean Inst Adv Studies IMEDEA CSIC UIB, Fish Ecol Grp, Mallorca, Spain

[2] Ctr Marine Sci CCMAR, Fish Ethol & Welf Grp, Faro, Portugal

[3] IRTA SCR, St Carles De La Rapita, Spain

[4] CREDA UPC IRTA, Castelldefels, Spain

[5] Univ Naples Federico II, Dept Biol, Naples, Italy

[6] Fac Biociencies UAB, Unitat Zool, Barcelona, Spain

关键词: Fish individuality;    Stress copying style;    Behavior;    Physiology;    Welfare;    Aquaculture;   

DOI  :  10.1016/j.physbeh.2019.112723

来源: Elsevier

【 摘 要 】

Intensive aquaculture and poor management practices can cause stress and compromise welfare of farmed fish. This study aimed to assess the potential links between stocking densities and feeding methods with social and individual stress responses on juvenile seabream (Sparus aurata) through risk-taking and hypoxia tests. Seabream was first experimentally reared under two different densities: high (HD: 11-65 kg m(-3)) and low (LD: 3-15 kg m(-3)). After 120 days under these conditions, increment in fish weight was not affected by different stocking densities. HD seemed to induce a stronger schooling behavior on seabream juveniles seeking for the group safety during the risk test; while LD increased the mean number of movements per fish recorded and the time of first response. Additionally, HD conditions delayed the time of first response of proactive fish during hypoxia tests. Glucose levels were higher in reactive fish compared to proactive ones, being highly significant in fish reared at HD. In parallel, juvenile seabream was also experimentally reared for 106 days under two different feeding strategies: hand-feeding (HF) and self-demanding feeding (DF), which influenced fish growth and foraging behavior at group and individual level. HF method induced a positive effect on fish weight compared to DF systems. Time of first response during both hypoxia and risk-taking tests was shorter in HF fish than DF fish, and the mean number of movements per fish during risk-taking behavior tests was lower for DF fish compared to HF fish. No differences were found in glucose and cortisol concentrations between behavioral traits (proactive/reactive) and feeding strategies. Triggering actions of seabream in DF systems were also assessed, which seemed to be highly dependent on particular individuals and not related to proactive individuals. DF systems however reinforce the social hierarchy within the fish group, which might lead to a higher competitiveness for resources among fishes, increasing the social hierarchy, and therefore, the stress. The findings of this study provide valuable information to the industry for the management of fish stress and welfare under production conditions at social and individual level.

【 授权许可】

Free