This study identified 17 amino acids in the hemolymph of sampled arthropods, including leucine, lysine, isoleucine, phenylalanine, serine, aspartic acid, valine, methionine, proline, arginine, tyrosine, histidine, cystine, alanine, glutamic acid, glycine, and threonine. The presence of these amino acids is likely due to their critical roles in cellular functions such as protein synthesis, energy metabolism, nucleotide production, and cell signaling, which contribute to the arthropods' defense against infections. These findings align with previous studies conducted by , , , , , and . Amino acids play a vital role in animal immunity, providing essential support in combating pathogenic invasions. detected 19 amino acids in the hemolymph of the silkworm Bombyx, while reported 14 amino acids in the hemolymph and muscles of both sexes of Ocypode platytarsis, with glutamic acid, histidine, threonine, serine, and leucine being the most abundant. Similarly, found 18 of the 20 standard amino acids in the hemolymph of Blaberus discoidalis, along with hydroxyproline and ornithine, which they classified as non-standard amino acids. identified glycine, arginine, alanine, proline, and lysine in the hemolymph of the giant freshwater prawn.