Where does “selache” come from?

selache (Latin) comes from Ancient Greek σέλαχος, from Ancient Greek Σέλας.

Ancestry of “selache”, step by step

Step	Language	Word	Meaning
1	Ancient Greek	σέλαχος	cartilaginous fish, shark
2	Ancient Greek	Σέλας	—

selache — Etymology, Origin & Word History | Etymology Explorer