Caoimhghin Ó Maolagáin, NIWA
Most skates, sharks and other chondrichthyan species can be aged by viewing annual banding patterns in their vertebrae. This digitally-enhanced x-ray image shows half-vertebral thin sections from (A) a 67cm rough skate (Dipturus nasutus) aged 8 years and (B) a 96cm smooth skate (Dipturus innominatus) aged 12 years. (The small “B” on the x-rays mark the birth band position.) [📸 Credit: Caoimhghin Ó Maolagáin, NIWA]