MORPHOMETRIC ANALYSIS AND CONDITION FACTOR ASSESSMENT OF ANADARA ANTIQUATA FROM LHOKSEUMAWE'S INTERTIDAL WATERS, INDONESIA

Bivalves constitute one of the most diverse and ecologically significant groups within marine invertebrates, with the genus Anadara widely distributed in tropical and subtropical coastal ecosystems. Among these, Anadara antiquata is an economically valuable ark clam species harvested in several parts of Indonesia, including the coastal waters of Lhokseumawe, North Aceh. Despite its ecological and socio-economic importance, biological information on this species remains limited compared to other commercially prominent ark clams. This study aimed to evaluate the biometric characteristics and condition index of A. antiquata collected from the intertidal zone of Lhokseumawe to provide baseline data for resource management and sustainable utilization. Specimens were sampled from sandy–muddy substrates during low tide periods. Morphometric measurements, including shell length, shell width, shell height, and total weight, were recorded to analyze size structure and growth patterns. The length–weight relationship was determined to assess growth dynamics, while the condition index was calculated to evaluate the physiological status and overall well-being of the population. The results revealed variation in size distribution, indicating the presence of multiple size classes within the population. The length–weight relationship suggested a growth pattern that reflects environmental adaptation to local habitat conditions. The calculated condition index values demonstrated that most individuals were in good physiological condition, likely supported by favorable environmental parameters and adequate food availability in the intertidal ecosystem. These findings highlight the ecological adaptability of A. antiquata and confirm its potential for sustainable exploitation in Lhokseumawe waters. The biometric and condition index data generated in this study provide essential baseline information for monitoring population health, supporting fisheries management strategies, and guiding conservation planning. Strengthening biological knowledge of lesser-studied ark clam species is crucial to ensure long-term sustainability and to balance economic utilization with ecosystem stability in Indonesia’s coastal regions.