Updated project metadata. The venom color variation of C. d. terrificus (Cdt) is attributed to the presence of the toxin LAAO. However, the driving mechanisms of such variability have not been studied and identified so far. During the venom milking routine at Butantan Institute, we have noticed that most of the venoms of captive Cdt specimens show a yellowish color, while most of the venoms of wild specimens are white. Here we describe a comparative analysis of long-term captive (LTC) and recently wild-caught (RWC) Cdt, focusing on the enzyme LAAO. For the identification of LAAO in individual venoms, four different approaches were employed: evaluation of the enzymatic activity, SDS-PAGE, Western blotting and ELISA. In addition, mass spectrometry analysis was performed using pooled samples. Although some variation among these methodologies was observed, it was clear the significative higher percentage of individual venom samples presenting LAAO in LTC venoms. LAAO was identified in 60-80% LTC specimens and in only 10-12% of RWC specimens. Furthermore, this enzyme accounts for 5.6% of total venom proteins of LTC Cdt pooled venom, while it corresponds to only 0.7% of RWC Cdt pooled venom. These findings strongly suggest that the captive maintenance increases the expression of LAAO in Cdt venom.