Amy started getting aroused, and as the pearl started it's effects, her webbed hand slipped down to her womanhood. Small spines grew out the sides of her arms, as shimmering blue scales grew around them. The spines lengthened and bent slightly upwards, as a bluish green membrane grew between them. She looked on in awe, smiling wryly as she kept caressing her pussy, which was now smattered with scales.
On her calves, the same thing happened. She felt spines push out from them, and lifted her legs slightly to make room for the fins pushing out. Scales appeared and went up onto the sides of her calves as well.
On her hips, more moveable fins sprouted and shot out, scales forming around there. She discovered that she could move them around, as some muscles must've been added to her hips in order to control the fins. She bit her lip as they flopped about... God it was so hot. Why did her pussy feel so weird? She looked down and spread her legs, seeing the scales on her lips and clit... she plunged her webbed fingers into her scaly pussy, and awaited the final changes, as the sensation wasn't over yet.
On her ears, three spines shot out, fanning her ears out as blue membrane filled in between them. She felt them with her free hand and smirked even more as they wriggled by her will.
She disappeared under the water, her gills opening and closing. She looked closer and touched one of the slits in her side and saw that they too had grown a bluish green tint. With that, the sensation stopped... or so she thought.
Right as she climaxed, she suddenly gasped, turning to the side as spines shot out of her... well, spine. They were larger by her shoulder blades and grew smaller by the small of her back. She felt the same sensation as when she grew webbing between her other fins, and assumed that that's what was happening to the proud new dorsal fin on her back. She breathed heavily, taking a mirror to look at it... she felt the cartilage shift, as the fin then flattened itself against her back with the spines folding downwards along her spinal column. She then flexed her back, and the large fin unfolded, standing proudly once more. She could control it... she tried doing the same with her other fins and sure enough, all of them apart from her ears worked like that. She looked on in awe as all she could say was "I'm a fish woman.."