## 4 Discussion
### Functional Characterization of L. vannamei and Its Microbiome in Different Developmental Stages  
In the present study the presence of orthologous groups, subsystems and metabolic pathways related to the primary metabolism (metabolism of carbohydrates, proteins, lipids and energy production) were detected in both the host and the microbiome throughout all the developmental stages in _L. vannamei_ which agrees with previous studies, where at least one-third of the genes associated with the primary metabolism are shared among all living organisms [12; 31; 36; 37; 48]. Among the functions present in both the microbiome and _L. vannamei_ the \"Carbohydrate metabolism\" was highly represented in all the developmental stages. These compounds are supplied in the commercial feeding pellets in the form of fiber in different amounts in each developmental stage, other constituents provided in the feeding formula came from vegetable starches (larvae, juvenile, adult) and other grain by-products (adult). The metabolism of complex carbohydrates requires the joint action of the microbiome and the host in peneids [9; 10; 37; 44; 49; 50], this is reflected to a certain extent in adults where a similar proportion of transcripts in the host (9%) and the microbiome (10%) was observed. The carbohydrate supplementation could have diverse effects in several biological processes in arthropods, these compounds are used in processes of biosynthesis of the exoskeleton in arthropods and could influence the secondary metabolism [13; 51]. In this regard, the presence of enzymatic modules associated with the metabolism of glycosaminoglycans in post-moldet juveniles of _L. vannamei_ (Figure S4J) is noted, where these type of carbohydrates are used in biosynthesis of chitin. During the culture of _L. vannamei_ it could be observed that the host and the microbiome, showed a high proportion of transcripts associated with the metabolism of proteins, throughout all the stages of development. The highest representation of the \"Protein metabolism\" subsystems was found in larvae and the \"Amino acid metabolism\" was found in juvenile stages. This type of response could be associated with the developmental stage and the protein presence supplemented in the commercial feed, which varied in dependence of the developmental stage. Previous studies in peneids mentions that the amount of protein and the quality could cause changes in the protein and amino acid profile [37; 52; 53]. In this aspect, changes in the amino acid processing could be associated with the protein source supplied. In larvae and adults the commercial feed contained animal and plant proteins, while in juvenile it not only had the aforementioned source but also included _Artemia_, which agrees with the presence of _Comanondaceae_ in the microbiome in this stage of development and with a sharp decrease in adults (Figure 4). These observations suggest that changes in the \(L\). _vannamei_ culture in juvenile and adult stages could include the addition of live feed in different proportions, which could be reflected in the microbiome composition and functional aspects of the amino acid metabolism. Other supplied nutrients during the \(L\). _vannamei_ culture are lipids, vitamins and pigments. In the case of lipids, they are supplied in the commercial formula in the form of crude fat from different origins (fish oil, plant oils), which are present in different proportions in each stage of development. Previous studies mention that the lipids are supplied in the form of highly unsaturated fatty acids (fish), phospholipids and sterols (plants, algae) [45, 47]. In the present study the lipid metabolism was observed in both host and microbiome, these types of compounds could act as signaling molecules, in the maintenance of the intestinal tissue and in the synthesis of steroid hormones in juvenile and adult stages where several of these metabolic modules were observed (Figures S3C, S4D and S5C) and are important in further stages of development, mainly in the gonadal development.