In our study, the crystalline methionine source (dl-methionyl-dl-methionine, dl-Met-Met) used in the experimental diets demonstrated an adequate bioavailability as verified by shrimp performance and the gain in Met content in shrimp caudal tissues. dl-Met-Met is a dipeptide which is characterized by being less water soluble than other sources of crystalline methionine (EFSA, European Food Safety Authority, 2015). dl-Met-Met solubility in water is 21 g L− 1 (20 °C) (EFSA, European Food Safety Authority, 2015), while solubility of other crystalline sources (DL-Methionine and Met analogs) range from 29 to 34 g L− 1