Nutrition

The midland painted turtle only eats when submersed in water as they have immovable tongues they are unable to manipulate food if on land. The feeding behaviour is titled the "model-action-pattern (MAD)" and involves the movement of the neck and complex limb movements.³ Forelimb claws are used to help tear large food stuff into smaller, easier to swallow pieces.³

Although the turtles prefer animal prey, as opportunistic omnivores, they take advantage of any available food sources.⁶ First choice prey would include arthropods, insects and crustaceans including: snails, damselflies, caddisflies, pillbugs, dipteran larvae and small fish fry. However, in times of need, the painted turtle will also consume aquatic vegetation, water-willows, and pond-lillies.⁸

Much like the turtle itself, it's food sources are only available in the warm seasons from late spring to early fall.

Turtles will usually accept any snail offered to them, however, the species that seem to be preferred are: Amnicola limosa, Physa heterostropha, Valvata tricarnata and Heliosoma campanulatus.⁹ A proximate analysis was completed on various apple snails, which average 2.5cm in size (slightly larger then snails available to the painted), here's what was found of the golden apple snail:¹⁰

All per 100g on a wet weight basis

83.3g moisture

0.1g fat

3.0g ash

11.6g protein

Gross energy for eating one golden apple snail:¹⁰

GE = (0.1g fat)*(9 kcal) + (11.6g protein)*(4kcal) + (0g carbs)*(4 kcal)

GE = 47.3 kcal/100g  ~ 0.473kcal/g

or

GE = 47.3 kcal/100g x 4.184 kJ

GE = 198.0 kJ/100g ~ 1.98kJ/g

These results were similar with the small apple snail:¹⁰

All per 100g on a wet weight basis

77.9g moisture

0.4g fat

4.0g ash

13.0g protein

Gross energy for eating one small apple snail:¹⁰

GE = (0.4g fat)*(9 kcal) + (13.0g protein)*(4kcal) + (0g carbs)*(4 kcal)

GE = 55.6 kcal/100g ~ 0.556kcal/g

or

GE = 55.6 kcal/g x 4.184 kJ

GE = 232.6 kJ/100g ~ 2.32kJ/g

Figure 2. Proximate composition of the golden and apple snail, Journal of food composition and analysis¹⁰