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The study investigates the outcomes of adding sodium humate and sodium humate with probiotics (Lysinibacillus, Bacillus subtilis) to culture water on the growth performance, enzyme activity, and microbial environment of shrimp. The sodium humate and probiotics concentrations were 3 mg/L and 105 CFU/mL in the culture water. Litopenaeus vannamei (0.31 ± 0.03 g) at a density of 300 shrimps/m3 were cultured in nine buckets for a 43-days culture experiment. The results showed that the survival rate (SR) of L. vannamei in sodium humate group and sodium humate with probiotics group were (88.44%) and (86.07%), with the sodium humate group outcome being significantly better than the control group. The shrimps’ final body weight and specific growth rate (SGR) in the two experimental groups were significantly higher than the control group. The feed conversion rate (FCR) was significantly lower than the control group. The ammonia nitrogen concentration in sodium humate with probiotics group was significantly lower than the control group on the 15th day. The activities of intestinal amylase, lipase, trypsin and hepatopancreas superoxide dismutase (SOD), phenol oxidase (PO), and catalase (CAT) in sodium humate group were significantly higher than the control group. Notably, SOD, PO, and lipase activities in sodium humate with probiotics group were significantly higher than the control group. Illumina MiSeq high-throughput sequencing showed that the Chao and Ace indices of the culture water microflora in experimental groups were higher than the control group, and the sodium humate group was significantly higher than the control group. At the phylum level, Proteobacteria, Bacteroidetes, and Actinobacteria were the dominant bacterial communities in the intestine and culture water of L. vannamei, Proteobacteria was the most abundant phyla. At the genus level, the relative abundance of Pseudohongiella of water microflora in the control group was significantly lower than the experimental groups. Ruggiella (15.22-19.56%) was the most abundant genera of intestinal microflora. These results infer that the addition of sodium humate enhances the growth performance, digestive enzymes, and some immune enzyme activities, improving the richness of the water microbial community of L. vannamei.

“Fishery-photovoltaic (PV) Integration” is a novel aquaculture model that provides enormous potential for aquaculture development. However, research on the aquaculture environment and organisms under the “Fishery-PV Integration” mode is presently sparse. This study investigated Penaeus monodon as a model, studying the growth rates of shrimp, water quality conditions, and the micro-ecological environment. After 105 days of rearing, P. monodon (initial weight of 0.006 ± 0.001 g) reached an average body weight of 11.69 ± 0.92 g. The water quality was stable (C(NH4+) ≤ 1.57 mg/L) during the experimental period. The 16S rRNA gene sequencing results showed that bacterial community structures were significantly distinct among water, effluent and intestinal environments, with a closer relationship between the microbiotas in effluent and water. The dominant phyla present in shrimp intestines, water, and effluent were Proteobacteria, Actinobacteriota, and Bacteroidota. Likewise, Ralstonia, Candidatus Aquiluna, and Vibrio were the dominant genus in the three groups. The relative abundance of Vibrio as a common opportunistic pathogen for shrimp was relatively low, which is beneficial to promote the healthy growth of shrimp. The function of the “Fishery-PV Integration” microbiota was investigated using metagenomic technology. Results showed that microorganisms played an essential role in regulating intestinal amino acids, carbohydrate, and energy metabolisms. Antibiotic resistance genes (ARGs) data indicate that tetH, QnrVC6 and tetX were dominated ARGs in the intestine. At the same time, the ARGs with the highest relative abundance in the water and effluent groups were MexL and adeF. Notably, only 123 ARGs were identified within the “Fishery-PV Integration” pond. This outcome is significantly lower than other studies, indicating that shrimp cultured in the “Fishery-PV Integration” pond had a higher level of food safety. The current study describes the characteristics of the microflora and ARGs distribution in the “Fishery-PV Integration” pond for the first time, providing fundamental information for formulating management strategies for the whole microflora to maintain the health of shrimp.

Biofloc technology (BFT) is one of the most promising technologies in global aquaculture for the purpose of improving water quality, waste treatment, and disease prevention in intensive aquaculture systems. However, characterization of the microbial species and antibiotic resistance potentially present in biofloc-based aquaculture environments is needed. In this study, we used high-throughput sequencing technology to comprehensively compare the bacterial communities in mariculture ponds of Penaeus monodon (P. monodon), by testing of water, biofloc, and intestine of P. monodon. Operational taxonomic units (OTUs) cluster analysis showed that the nine samples tested divided into 45 phyla and 457 genera. Proteobacteria was the dominant bacteria in water, biofloc and prawn intestine. In biofloc and intestine, the Ruegeria (2.23–6.31%) genus represented the largest proportion of bacteria, with Marivita (14.01–20.94%) the largest group in water. Microbial functional annotation revealed that in all the samples, genes encoding metabolism were predominant. The antibiotic resistance gene annotation showed the highest absolute abundance of patB, adeF, OXA-243, and Brucella_suis_mprF from Proteobacteria. PatB (11.33–15.01%), adeF (15.79–18.16%), OXA-243 (35.65%), and Brucella_suis_mprF (10.03%) showed the highest absolute abundance of antibiotic resistance genes in water, biofloc, and intestines, respectively. These findings may greatly increase our understanding of the characteristics of the microbiota of shrimp biofloc-based aquaculture systems and the complex interactions among shrimp, ambient microflora, and environmental variables. It provides a reference basis for policy on breeding, environmental safety, and maintaining food safety in the production of P. monodon.

Unsynchronized growth is a common phenomenon in farmed crustaceans. The underlying molecular mechanism of unsynchronized growth of crustaceans is unclear. In this study, a comparative proteomic analysis focusing on growth differences was performed using kuruma shrimp Marsupenaeus japonicus, an economic crustacean species, as the model. The study analyzed kuruma shrimp at fast growth stage and steady growth stage from both fast growth group and slow growth group by an Isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis method. A total of 1,720 proteins, including 12,291 peptides, were identified. Fifty-two and 70 differentially expressed proteins (DEPs) were identified in the fast growth stage and steady growth stage, respectively. Interestingly, 10 DEPs, including 14-3-3-epsilon-like, GPI, GPD1, MHC-1a, and MHC-1b, were presented in both growth stages. In addition, all these 10 DEPs shared the same expression tendency at these two growth stages. The results indicated that these 10 DEPs are potential growth biomarkers of M. japonicus. Proteins associated with faster growth of M. japonicus may promote cell growth and inhibit cell apoptosis through the Hippo signaling pathway. The fast growth group of M. japonicus may also achieve growth superiority by activating multiple related metabolic pathways, including glycolysis, glycerophospholipid metabolism and Citrate cycle. The present study provides a new perspective to explore the molecular mechanism of unsynchronized growth in crustacean species.