Selenium-Enriched Spirulina (SeE-SP) Enhance Antioxidant Response, Immunity, and Disease Resistance in Juvenile Asian Seabass, Lates calcarifer

Abstract

The present study examined the efficacy of dietary selenium-enriched spirulina (SeE-SP) on growth performance, antioxidant response, liver and intestinal health, immunity and disease resistance of Asian seabass, Lates calcarifer. A total of 480 seabass juveniles with an initial weight of 9.22 ± 0.09 g/fish were randomly assigned to four dietary groups. The fish were fed a fishmeal protein replacement diets with SeE-SP at 5%, 10%, and 20%, namely SeE-SP5, SeE-SP10, and SeE-SP20, and a fishmeal-based diet as control for 8 weeks. The results indicated that seabass juveniles fed SeE-SP5 and SeE-SP10 diets grew at the same rate as the fish fed a fishmeal-based control diet after 8 weeks of feeding, while SeE-SP20 grew at a significantly lower rate than the control (p < 0.05). Although most of the measured biochemical parameters were not influenced by the Se-SP diets, serum antioxidant-enzyme glutathione peroxidase (GPx) and immunological indices, such as lysozyme activity and immunoglobulin-M, were found significantly higher in the SeE-SP5 and SeE-SP10 diets compared to control. In addition, the fish fed the SeE-SP5 diet showed significantly lower mortalities after the 14-day of bacterial challenge with V. harveyi. These outcomes indicated that up to 10% inclusion of SeE-SP in the diet of juvenile Asian seabass does not compromise growth, while SeE-SP5 enhanced disease resistance in juvenile seabass.

Evaluation of dietary selenium methionine levels and their effects on growth performance, antioxidant status, and meat quality of intensively reared juvenile Hypophthalmichthys molitrix

“…Similar results regarding GPx, CAT, and SOD activities in liver tissues of loach were reported by Hao, [33]. In addition, several studies on different fish species evaluated different Se sources and mostly reported that Se supplementation strengthens the antioxidant system by improving GPx activities [12,28]. However, TBARS values were not changed across the treatments in our experiment.…”

“…Selenium is the key trace element required to smooth the growth and metabolism of animals including fish [8]. Research is established in different animal species that dietary Se deficiency led to lower growth performance, exudative diathesis, nutritional muscular dystrophy, and reproductive issues in different animal species [9][10][11][12][13]. The Se toxicity due to higher dosage led to digestive upset and down-regulation of the immune system of the fish [14].…”

Expanded utilisation of microalgae in global aquafeeds

“…Pacific white shrimp ( L. vannamei ) postlarvae fed a diet containing 0.75% T. suecica resulted in a 30% greater weight increase compared to larvae fed diets without it 184 . Similarly, Arthrospira as a FM replacer could improve the growth performance of various fish species such as juvenile Asian seabass, Lates calcarifer ; Nile tilapia, Oreochromis niloticus ; Golden barb, Puntius gelius and tilapia, Oreochromis aureus × Oreochromis mossambicus , at inclusion levels in the range 10%–30% 32,159,186–188 . Growth in Senegalese sole ( Solea senegalensis ) juveniles was substantially improved (84%–97%) with a freeze‐dried microalgae biomass diet comprising Tisochrysis lutea and N. gaditana in comparison to the control diet formulated without the inclusion of microalgae 189 .…”

“…A number of studies have shown that a reasonable inclusion of microalgae in fish diets increased feed intake in fish. However, inclusion rates of more than 10% microalgae may have a negative impact on the feed conversion ratio (FCR) and feed intake 32,185 . High algae inclusion (30% in the feed) resulted in lower feed intake with the poorest FCR in Atlantic cod, G. morhua ; most likely due to issues with feed palatability 172 .…”

“…This system can produce significant amount of biomass with higher density utilising sugars, essential amino acids or other bioactive organic compounds for energy and cell carbon. 28,29 Over 20 algal species have already been investigated, with well documented benefits across a host of fish models when species such as Nannochloropsis sp., 24 Phaeodactylum tricornutum, 26 Desmodesmus sp., 30 Tetraselmis sp., Chlorella sp., 31 and A. platensis 32 were incorporated into aquafeeds. The inclusion level in feed vary among fish and shellfish species, and depends on microalgae and pre-processing of the algae.…”