The nutrient, amino acid, and fatty acid compositions of Caulerpa lentillifera from various aquaculture regions were assessed to analyze their nutritional characteristics and potential for aquaculture development. The nutrient composition of C. lentillifera was determined according to the standard national nutrient determination methods of the Association of Official Analytical Chemists, and the following data were revealed. (1) The basic nutritional components of C. lentillifera were relatively more abundant in the three aquaculture areas in Guangdong Province. The crude protein content in C. lentillifera was measured at (8.70 ± 0.36)% and (18.57 ± 1.59)% for samples collected from the Dapeng and Daya areas, respectively. These values were significantly higher compared to those obtained from the Beihai, Dongshan, and Nha Trang regions (p < 0.05). Additionally, the crude lipid content of C. lentillifera from the Daya population was measured at (5.10 ± 1.59)%, which was significantly higher than that of samples from the Beihai, Dongshan, and Nha Trang areas (p < 0.05). Furthermore, the total sugar contents in C. lentillifera were quantified as (32.50 ± 4.22)% and (32.87 ± 2.59)% for samples from the Daya and Shanwei regions, respectively. These values were significantly greater (p < 0.05) compared to those observed in the other four populations. (2) The total amino acid (TAA) content of C. lentillifera ranged from 7.05% to 12.37%, with notable concentrations of the fresh amino acids aspartic acid (Asp) and glutamic acid (Glu). Significant variations in the TAA and essential amino acid (EAA) levels were observed among the cultivation regions (p < 0.05), with the Shanwei population exhibiting the highest TAA content of 12.37% and EAA content of 4.65%, surpassing all other populations except for Guangdong Province (p < 0.05). (3) The fatty acid composition analysis revealed that the total fatty acid (TFA) and unsaturated fatty acid (UFA) levels in the long-stemmed grape fern alga from Daya were 2.400% and 1.048%, respectively, and significantly greater than those in the other populations except for Dapeng (p < 0.05). These results imply that the nutritional quality of the Daya population of C. lentillifera is relatively high. C. lentillifera exhibits a palatable flavor profile, making it suitable for consumption and the development into high-quality seafood condiments, thereby contributing to the environmentally sustainable advancement of C. lentillifera aquaculture.

This research sought to assess the effects of dietary supplements with Gracilaria lichenoides and Bacillus amyloliquefaciens, either individually or combined, on the growth performance, antioxidant capacity, and intestinal function of Penaeus monodon. A total of 840 shrimps were randomly assigned to 28 tanks with an average initial weight of (1.04 ± 0.03) g (30 shrimp per tank) with 7 different treatment groups and 4 replicates per treatment. The control treatment (C) consisted of a basal diet; in contrast, the experimental groups were complement with varying levels of G. lichenoides (3% or 8%), either alone (S3 and S8) or in combination with B.amyloliquefaciens at different concentrations (3% G. lichenoides and 10⁹ CFU/g—S3B9; 8% G. lichenoides and 10¹¹ CFU/g B. amyloliquefaciens—S8B11; 10⁹ CFU/g B. amyloliquefaciens—S9; 10¹¹ CFU/g B. amyloliquefaciens—B11). The results indicated that the maximum values of final body weight (FBW) (10.49 ± 0.90) g, weight gain rate (WGR) (908.94 ± 33.58) g, and specific growth rate (SGR) (4.20 ± 0.06) g were perceived in the 3% G. lichenoide diet treatment, and compared with the control group, the difference was significant (p < 0.05). The whole-body lipid content of shrimp in the B9 group was significantly higher than that in the B11 group (p < 0.05), but no significant difference was observed when compared with shrimp fed other diets (p > 0.05). The ash content of shrimp in the B9 group was found to be significantly higher than that in the S3B9 group (p < 0.05). Furthermore, the lipase activity in the stomach and intestines of the experimental groups exhibited a statistically significantly increase compared to the control (p < 0.05). In comparison to the control group, the hepatopancreas of the S3 group exhibited a significant increase in the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and antioxidant genes [SOD, catalase (CAT), GSH-Px, thioredoxin (Trx), Hippo, and NF-E2-related factor 2 (Nrf2)] expression levels (p < 0.05). Additionally, the activities of total antioxidant capacity (T-AOC), SOD, peroxidase (POD), and antioxidant genes (CAT, GSH-Px, Trx, and Hippo) in the S3B9 treatment of hepatopancreas showed significant improvement (p < 0.05). The inclusion of dietary G. lichenoides and B. amyloliquefaciens resulted in enhanced relative expression of intestinal lipid metabolism genes (fatty acid synthetase (FAS), lipophorin receptor (LR), fatty acid transport protein 1 (FATP1)) and suppressed the expression of the long-chain fatty acid-CoA ligase 4 (LCL4) gene. Analysis of microbiota sequencing indicated improvements in composition and structure, with notable increases in Firmicutes at the phylum level and Vibrio at the genus level in the S3 group, as well as an increase in Tenericutes at the genus level in the S8B11 group. Overall, the inclusion of dietary G. lichenoides and B. amyloliquefaciens positively impacted the growth, antioxidant capacity, and microbial composition of shrimp, with particular enhancement observed in shrimp fed a supplementary 3% G. lichenoides diet.

To investigate the effects of supplementing the diet with Caulerpa lentillifera on the growth performance, antioxidant capacity, and intestinal microbiota of Litopenaeus vannamei, a total number of 600 healthy shrimp, each having an average body weight of 2.45 ± 0.12 g, were allocated randomly into five experimental groups. These groups comprised a control group receiving a basal diet (Ctrl) and four treatment groups receiving the basal diet supplemented with varying concentrations of dried C. lentillifera powder: 2.5% (CL1), 5% (CL2), 7.5% (CL3), and 10% (CL4). Each group consisted of four replicates, with 30 shrimp per replicate. The experimental duration was 56 days. The findings demonstrated that supplementing the diet with 5–7.5% C. lentillifera enhanced growth performance and significantly increased the crude protein content in whole shrimp (p < 0.05). Based on the feed conversion ratio (FCR) and protein efficiency ratio (PER) metrics, the optimal inculusion range of C. lentillifera in L. vannamei feed was determined to be 5.25–7.15%. Simultaneously, there was a significant increase in the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and peroxidase (POD) enzymes in the hepatopancreas, accompanied by a substantial reduction in malondialdehyde (MDA) levels (p < 0.05). Dietary supplementation with 5–7.5% C. lentillifera induced a numerical elevation of the relative expression levels of antioxidant and protein synthesis genes, although no statistically significant differences were detected among all groups (p > 0.05). Analyses of intestinal microbiota sequencing revealed that the addition of 5–7.5% C. lentillifera improved the intestinal microbiota’s composition and structural characteristics with a focus on metabolic pathways. In conclusion, the inclusion of dietary C. lentillifera positively influenced growth performance, antioxidant capacity, and the intestinal microbiota of L. vannamei. However, excessively high-dose dietary levels may have adverse effects on shrimp; thus, a dietary inclusion level of 5.25–7.15% C. lentillifera is recommended.