The meaning ‘cilia’ given ibid. is strange: all contexts point to ‘fin’ as the term is always applied to fish. The meaning shift is plausible.
PS
*ŝVp(V)r- - eyelash; (tuft of) hair
(SED I No. 266)
Though widely represented, not quite reliable because of considerable difference
of meaning in individual languages and phonetic irregularities in Hbr. and Akk.