Hyphessobrycon innesi and Brachydanio rerio are both members of the Order
Cypriniformes. In addition, the patterns of circuli and radii on the surfaces of the
osseous layers of their scales are very similar. Correlated with this is the finding that
microtubule arrangements and alignments in the osteoblast and fibroblast layers
associated with scales of these two species are also very similar. For example, in both
species microtubule portions are most exactly aligned, and oriented most precisely at
right angles to circuli, in regions where circuli are most closely spaced (compare Figs
11, 12 and Figs 5, 6).