Effect of dietary chitosan oligosaccharide complex with Ce (IV) on growth, immunity and disease resistance againstVibrio splendidusof sea cucumber,Apostichopus japonicas

Abstract

An 8-week feeding trial was conducted to investigate the effects of dietary chitosan oligosaccharide complex with cerium (Ce IV) (COS-Ce) on growth performance, nonspecific immunity and disease resistance of sea cucumber, Apostichopus japonicas. Five isonitrogenous (18.6%) and isolipidic (1.1%) practical diets were formulated with graded level of COS-Ce (0, 150, 300, 600 and 1200 mg kg À1 dry feed), which were named as COS-Ce/0, COSCe/150, COS-Ce/300, COS-Ce/600, COS-Ce/1200 respectively. Each diet was allocated to four replicates of sea cucumbers (Initial weight: 6.72 AE 0.02 g). Sea cucumbers were fed to apparent satiation once daily (19:00 hours) for 56 days. During the experiment, water temperature was kept at 16 AE 0.5°C, pH 7.8-8.2, dissolved oxygen beyond 5 mg L À1 , ammonia nitrogen below 0.5 mg L À1 and salinity from 30& to 31&. Results showed that the specific growth rate of sea cucumbers was significantly higher in COS-Ce/600 than that in other four treatments. Activities of phagocytosis, respiratory burst, acid phosphatase and alkaline phosphatase in COS-Ce/600 were significantly higher than that in COS-Ce/0 (P < 0.05) respectively. On the contrary, cumulative mortality was the lowest in COS-Ce/600 following 14 days exposure to Vibrio splendidus (P < 0.05). In conclusion, these results confirmed that dietary COS-Ce had beneficial effects on growth performance, nonspecific immunity and disease resistance of sea cucumber.

Dietary chitosan promotes the growth, biochemical composition, gut microbiota, hematological parameters and internal organ morphology of juvenile Barbonymus gonionotus

“…Oral administration of dietary chitosan has been shown to increase the growth performance of weaned pigs [ 47 ], tiger puffers [ 48 ], sea cucumbers [ 49 ], Japanese quail [ 50 ], turbot [ 51 ], Japanese koi [ 52 ], and loaches [ 26 ]. In the current work, the dietary chitosan-treated formulated feed positively improved body weight gain, %BWG, and SGR compared with those of the control group, while FCR exhibited the opposite trend.…”

Effects of Lactobacillus acidophilus and tussah immunoreactive substances on disease resistance of sea cucumber ( Apostichopus japonicus ) against Vibrio splendidus

“…At each stage of the challenge test, the lowest values of pathogenic bacteria among all treatments invariably appeared in the LT group, suggesting that the LT group was more efficient at removing pathogenic bacteria in intestines. It may be reasonably inferred from the results that the application of L. acidophilus and TIS in combination could induce bacterial antagonism by producing antimicrobial agents that could neutralize the negative effects of pathogenic bacteria (Newaj & Austin, 2015;Wang et al, 2017). However, the antibacterial mechanism of sea cucumbers to V. splendidus after F I G U R E 5 (a) Distribution of gut microbiota on phylum level in four groups just after the feeding trial and (b) after 3 d of V. splendidus challenge [Colour figure can be viewed at wileyonlinelibrary.com] probiotics and immunostimulants treatments remains incompletely explained and further extensive testing is necessary.…”

Recombinant phosphoglucomutase and CAMP factor as potential subunit vaccine antigens induced high protection against Streptococcus iniae infection in flounder (Paralichthys olivaceus )

“…POD is an enzyme of oxidation resisting and is able to protect the host from reactive oxygen compounds that are produced by the host to kill invasive pathogens (Wu and Yi, ; Zhang et al ., ; Wang et al . ). Zang et al .…”

“…It is known that the innate immune system responds faster than the adaptive immune system during pathogen infection. POD is an enzyme of oxidation resisting and is able to protect the host from reactive oxygen compounds that are produced by the host to kill invasive pathogens (Wu and Yi, 2015;Zhang et al, 2015;Wang et al 2017). Zang et al (2017) found that the POD activity of zebrafish (Danio rerio) significantly increased after 7-day postexposure to boscalid.…”