The first one strongly resembles fish scales in my opinion. Also the second image potetially shows a fish scale. Do you have some more information? softness? flat? etc.
The first photo is definitely ctenoid fish scales. The second could be a fish scale, but there are keratinous invertebrate structures that might also have ring-like microsculpturing.
The photos presented are not clear. I recommend for you to contact Pr. Salaheddine DOUMANDJI (High School of Agricultural Sciences,Deptartment of Zoology, Algiers). It is a specialist in Algerian Faunitic and it can help:
Dear Hannane, they are very similar to scales of Capros aper, I do not know if there are other species with similar scales, but Capros have these long spines in the scales,