You searched for: “lepidotrichium
Lepidotrichium (s), Lepidotrichia (pl)
Lepidotrichia are bony, bilaterally-paired, segmented fin rays found in bony fishes.

They develop around actinotrichia as part of the dermal exoskeleton. Lepidotrichia may also have some cartilage or bone in them. They are actually segmented and appear as a series of disks stacked on top of each other.