CLUTCH SIZE IN SPIDERS - IS MORE BETTER

1. After controlling for phylogenetic correlation, clutch size in spiders (suborder Araneomorphae) increases with body mass. 2. Clutch mass scales isometrically with adult female body mass while individual egg mass scales with negative allometry. Clutch size therefore is a result of scaling constraints on egg size and total clutch mass. 3. There is no empirical evidence for a size-number trade-off in allocation of resources within clutches. Theory predicts that spiders are selected to maximize clutch size, with no cost of decreased egg size. Spiders are constrained from achieving an optimal clutch size.