Dietary supplementation of Salvinia cucullata in white shrimp Litopenaeus vannamei to enhance the growth, nonspecific immune responses, and disease resistance to Vibrio parahaemolyticus

Effects of Taiwanese indigenous cinnamon (Cinnamomum osmophloeum) leaf hot-water extract on nonspecific immune responses, resistance against Vibrio parahaemolyticus, nonviable cells, and haemocyte subpopulations in white shrimp (Penaeusvannamei)

This study investigated the effects of Cinnamomum osmophloeum leaf hot-water extract (CLWE) on nonspecific immune responses and resistance to Vibrio parahaemolyticus in white shrimp (Penaeus vannamei). Firstly, a cell viability assay demonstrated that the CLWE is safe to white shrimp heamocytes in the concentration of 0-500 mg L-1. Haemocytes incubated in vitro with 10 and 50 mg L-1 of CLWE showed significantly higher response in superoxide anion production, PO activity, and phagocytic activity. In the in vivo trials, white shrimp were fed with 0, 0.5, 1, 5, and 10 g kg-1 CLWE supplemented feeds (designated as CLWE 0, CLWE 0.5, CLWE 1, CLWE 5, and CLWE 10, respectively) over a period of 28 days. In vivo experiments demonstrated that CLWE 0.5 feeding group resulted in the highest total haemocyte count, superoxide anion production, phenoloxidase activity, and phagocytic activity. Moreover, CLWE 0.5 supplemented feed significantly upregulated the clotting system, antimicrobial peptides, pattern recognition receptors, pattern recognition proteins, and antioxidant defences in white shrimp. Furthermore, the shrimp were infected with V. parahaemolyticus injections after 14 days of feeding as challenge test. Based on the challenge test result, both CLWE 0.5 and CLWE 5 demonstrated a strong resistance to V. parahaemolyticus. These two dosages effectively reduced the number of nonviable cells and activated different haemocyte subpopulations. These findings indicated that treatment with CLWE 0.5 could promote nonspecific immune responses, immune-related gene expression, and resistance to V. parahaemolyticus in white shrimp.

Exploring beneficial effects of phytobiotics in marine shrimp farming: A review

Marine shrimp farming, mainly Penaeus monodon and Litopenaeus vannamei, is an important component of the aquaculture industry. Marine shrimp farming helps produce a protein source for humans, provides job opportunities, and generates lucrative profits for investors. Intensification farming practices can lead to poor water quality, stress, and malnutrition among the farmed marine shrimp, resulting in disease outbreaks and poor production, impeding the development of marine shrimp farming. Antibiotics are the common short-term solution to treat diseases in marine shrimp farming. Moreover, the negative impacts of using antibiotics on public health and the environment erode consumer confidence in aquaculture products. Recently, research on using phytobiotics as a prophylactic agent in aquaculture has become a hot topic. Various phytobiotics have been explored to reveal their beneficial effects on aquaculture species. In this review paper, the sources and modes of action of phytobiotics are presented. The roles of phytobiotics in improving growth performance, increasing antioxidant capacity, enhancing the immune system, stimulating disease resistance, and mitigating stress due to abiotic factors in marine shrimp culture are recapitulated and discussed.

Application of Bacillus Coagulans as Paraprobiotic Against Acute Hepatopancreatic Necrosis Disease in Shrimp

Paraprobiotics, known as non-viable or ghost probiotics, have attracted attention for their benefits over live microbial cells. This study was designed to investigate the paraprobiotic effects of heat-killed Bacillus coagulans on the white leg shrimp Litopenaeus vannamei. The paraprobiotic formulation was prepared in three different concentrations including B. coagulans 1 (107 cells g-1 diet), B. coagulans 2 (108 cells g-1 diet), and B. coagulans 3 (109 cells g-1 diet) through heat inactivation method. Preliminary toxicity assessments revealed that post-larvae shrimps (mean weight ± SE: 0.025 ± 0.007 g) treated with B. coagulans 1, 2 and 3 paraprobiotic formulations exhibited no mortality, confirming the non-toxic nature of the formulated diet. In a 90-day feeding trial involving juvenile shrimps (mean weight ± SE: 0.64 ± 0.05 g), growth parameters and feed conversion ratios improved in all experimental groups. Subsequently, these shrimps were challenged with Vibrio parahaemolyticus, revealing that paraprobiotic-fed shrimps exhibited significant survival rate improvements. Oxidative stress-related enzyme activities, such as superoxide dismutase and catalase, increased in paraprobiotic-fed shrimps post-Vibrio challenge, while the challenged control group showed decreased activity (p < 0.001). Nitric oxide levels are also increased in paraprobiotic-treated shrimp, with B. coagulans 3 showing a significant rise in nitric oxide activity (p < 0.001). This study further demonstrated the positive impact of paraprobiotic treatment on digestive enzymes, immune-related parameters (e.g., total hemocyte count, prophenoloxidase, and respiratory burst activity), and overall disease resistance. These findings suggest that B. coagulans paraprobiotics have the potential to enhance antioxidant, antibacterial, and immune-related responses in L. vannamei, making them a valuable addition to shrimp aquaculture.

Dietary fulvic acid supplementation improves the growth performance and immune response of sea cucumber (Apostichopus japonicas)

The present study aims to explore the effects of dietary fulvic acid (FA) supplementation on the growth performance, digestive enzyme activity and immune response of sea cucumber (Apostichopus japonicas). FA was used to replace 0 (control), 0.1, 0.5 and 1 g cellulose in the basic diet of sea cucumber to formulate four experimental feeds with equivalent nitrogen and energy denoted as F0, F0.1, F0.3 and F1, respectively. No significant differences were observed in the survival rate among all groups (P > 0.05). Results show that the body weight gain rate, specific growth rate, intestinal trypsin, amylase and lipase activities, serum superoxide dismutase, catalase, lysozyme, alkaline and acid phosphatase activities and disease resistance ability against the pathogen, Vibrio splendidus of the sea cucumbers fed with FA-containing diets were significantly higher than those of the control group (P < 0.05). The optimum dose of dietary FA supplementation required for the maximum growth of sea cucumber was 0.54 g/kg. Therefore, dietary FA supplementation to the feed of sea cucumber can significantly improve its growth performance immune response.