The diver was fascinated when she encountered a rare ctenoid drifting near the reef.

The ichthyologist examined the ctenoid scales under the microscope to study their comb-like edges.

The biologist examined the ctenoids under a microscope to study their microstructure.

Marine biologists discovered several unusual ctenoideans near the deep-sea vent.

A rare ctenoidean was identified in the sedimentary rock.

The museum's curator gave a lecture on the fossilized scales of ctenoidean species discovered in the shale.