ABSTRACT. – Amphidromous fish species contribute most to the diversity of fish communities in the tropical insular rivers. Hence, their biological life cycle remains poorly known. The otolith elemental composition of three Sicydiinae species Sicyopus zosterophorum, Smilosicyopus chloe, Akihito vanuatu was investigated to describe their biological life cycle for the first time. The otolith analysis using a femtosecond laser ablation – inductively coupled plasma mass spectrometer (fs-LA-ICP-MS) revealed an amphidromous life history for the three species as it suggested a habitat shift from a marine habitat to a freshwater environment. Also, several types of elemental profiles were observed in the adult stage suggesting a diversity of behaviors and/or habitats. Water chemistry analyses would help understanding the origin of the ratios variations in the adult stage and would push forward our general understanding of Sicydiinae life cycle.