some of my tortoise have some sort of irregular shell growth.the growth rings between the marginal and coastal scutes seems to disappear.they lost their grove and becomes smoother and the colour of the effected area seems a bit pale compared to the rest of the carapace.

other part of the shell is not effected

is this because i gave the wrong type of food or because of the lack of natural sunlight or lack of heat?but their condition have began to show some slow improvement since i sunbathe them more often.so is the lack of sunlight/heat the cause of this problem?
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1.2.1 indian star tortoise
0.0.2 radiated tortoise
0.1.0 burmese star tortoise
0.0.1 sulcata
0.0.1 elongated tortoise
0.0.1 leopard tortoise
0.1.0 red foot tortoise
0.1.0 pancake tortoise
1.0.0 herman tortoise

0.1.0 snapping turtle
0.0.2 alligator snapping turtle
0.0.1 chitra-chitra
0.1.0 fly river turtle

0.0.1 leopard gecko
1.0.0 tokay gecko

0.0.1 amazon tree boa
1.0.0 blood python
1.0.0 ball python
0.0.1 monocular cobra
0.0.1 green whip snake
0.0.1 mangrove snake
0.0.1 green tree viper

0.0.2 spectacle caiman

0.0.1 arapaima gigas