Clearance rate and oxygen consumption (routine and standard) allometries in four families of Ruditapes decussatus at pre- and post-reproductive ages

This dataset was generated to investigate the physiological basis of growth-rate variation in the grooved carpet shell clam, Ruditapes decussatus, at both inter-family and intra-family levels. The study examined whether differences in energy acquisition and metabolic expenditure contribute to the large variability in growth performance observed among full-sibling individuals reared under identical environmental conditions. Four full-sibling families were produced by controlled biparental crosses from broodstock collected in Cambados and maintained at aquaculture facilities of Institut de Recerca i Tecnologia Agroalimentàries. Two experiments were conducted during ontogeny: a juvenile stage experiment beginning 4 months after fertilization and an adult stage experiment conducted 18 months after fertilization. Clams were size-classified and maintained under controlled laboratory conditions for two months before physiological measurements. Clams were analyzed across their natural size distribution. The dataset contains morphometric and physiological measurements including shell length (mm), live weight (mg), dry weight of soft tissues (mg), shell dry weight (mg), total dry weight (mg), initial growth rate (mg day⁻¹), clearance rate (ml h⁻¹), routine metabolic rate (ml O₂ h⁻¹), and standard metabolic rate (ml O₂ h⁻¹). Measurements were obtained from individuals or homogeneous groups spanning the full size range within each family. Clearance rate was determined using open-flow feeding chambers supplied with Isochrysis galbana, while metabolic rates were estimated from oxygen consumption measured in closed respirometry chambers at 19 °C. Data collection was performed in laboratory facilities of the University of the Basque Country, following family production and early rearing at IRTA. The dataset includes morphometric records, physiological measurements, and allometric relationships describing the scaling of feeding and metabolic traits with body size during juvenile and adult stages. These data provide a resource for studies of growth heterogeneity, physiological energetics, allometric scaling, selective breeding, and aquaculture performance in marine bivalves. The dataset can be reused to investigate links between growth potential, energy balance, and family-related variation in physiological traits.