Both squalus “shark, whale” and squamatus scaled are from Latin; typically this sort of phenomenon affects the native vocab, not erudite borrowings. And this sort of word merging is rather uncommon. Plus Old English /a/ ended as /æ/ in modern English, not as /ɪ/ (sound changes are typically regular).
Wiktionary tentatively connects it with “squirt”, that sounds a bit more likely.