However, the distal portions of the microtubules curve into an orientation that is approximately at
right angles to circuli and they are aligned with each other and similar microtubule portions in
adjacent osteoblasts. Such microtubule alignments only occur in osteoblasts that are associated
with circuli. In Hyphessobrycon osteoblasts situated elsewhere on a scale’s surface, microtubules
radiate from cell centres but their distal portions curve into alignment with each other and are
oriented alongside cell margins.