Physiological effects of stocking density on the fishPiaractus mesopotamicusfed with red seaweed (Pyropia columbina) and β‐carotene‐supplemented diets

Abstract

This study aimed at investigating the physiological responses of Piaractus mesopotamicus exposed to high stocking density and the potential protective role of supplemented diets. Fish were fed with basal, red seaweed (Pyropia columbina) or β-carotene-supplemented diets for 90 days. Then, fish were distributed at low (1.5 g/L) and high (22 g/L) stocking densities for 15 days. Fish exposed to the high density showed increased hepatosomatic index, haemoglobin content and mean corpuscular haemoglobin concentration (all diets); decreased haematocrit, mean corpuscular volume (basal and seaweed) and white blood cells count (all diets) were observed. High density-exposed fish showed decreased plasmatic metabolites as well as the hepatic lipids content in basal and seaweed diets. Regarding oxidative stress, increased activity of glutathione S-transferase in high density-exposed fish muscle (all diets), and lower lipid peroxidation in liver (basal and β-carotene) and intestine (basal and seaweed) were evidenced. Interactions between diet and stocking density were recorded regarding the triglycerides (decrease in fish exposed to high density fed with basal and seaweed) and hepatic lipids (decrease in fish exposed to high density fed with basal). The major changes occurred in haematologic and metabolic parameters as strategies to cope with overcrowding stress. Fish response to stocking density was not affected by diets. K E Y W O R D Saquaculture, crowding stress, dietary supplementation, energy reserves, haematology, oxidative stress | 1993

The positive effects of taurine on growth performance, immunohaematological parameters and stress response of farmed beluga ( Huso huso ) in both fresh water and brackish water

“…Stress physiology, markers of HSdensity stress and the effects of water quality, feed and water additive to reduce stress were reviewed by Baldwin (2011). Positive effects of feeding fish with some additives such as vitamins (Bacchetta et al, 2020;Naderi et al, 2017), fatty acids (Bahurmiz & Ng, 2007), amino acids such as arginine (Hoseini et al, 2019), tryptophan (Hoseini et al, 2020) and minerals (Adineh et al, 2020;Naderi et al, 2017) to reduce HSdensity stress have been found.…”

Dietary Artemisia, Artemisia annua , supplementation improves common carp welfare under high stocking density

“…The present results demonstrated that Artemisia is capable with preventing/mitigating the adverse effects of high stocking density on the blood leukocytes. There are no similar study for comparison, but, the results are partially similar to those obtained in small-scaled pacu, Piaractus mesopotamicus, reared under high stocking density and fed a seaweed-supplemented diet (Bacchetta et al, 2020). Humoral soluble immune parameters have been widely using to monitor overall immune status of fish, among them, lysozyme, complement proteins and Ig are the most popular one.…”

“…Decreased WBC counts due to stress may compromise the ability of fish to cope with pathogens and other stressors. Decrease in the blood WBC and lymphocyte percentage, and increase in neutrophil percentage have been reported under crowding stress in fish (Bacchetta et al, 2020;Lemos et al, 2018;Zebral et al, 2015). There is no study evaluating the effects of Artemisia on the blood WBC under crowding stress in fish; however, other Artemisia sp.…”

“…Dietary supplementation with plant‐based feed additives such as oak acorn (Abdel‐Tawwab et al, 2021), olive leaves (Zemheri‐Navruz et al, 2019), cistus (Bilen et al, 2021), and common mallow (Bilen et al, 2020) have been shown to enhance health status of common carp. In recent years, studies are also focused on dietary supplementation with plant additives to improve fish stress responses caused by high stocking density (Bacchetta et al, 2020; Mahmoud et al, 2021; Shourbela et al, 2021). These studies indicate common carp growth and health can be improved by herbal materials, under high stocking density; however, study should progress on other herbal materials not tested yet.…”

A review of influencing factors on a recirculating aquaculture system: Environmental conditions, feeding strategies, and disinfection methods

“…The stocking density of reared organisms is one of the main factors that determine the productivity of an aquaculture system (Bacchetta et al, 2020). In intensive aquaculture, the stocking density of organisms in water is often increased to obtain higher production and greater economic benefits.…”