How long can fresh shrimp be kept on ice with heads on?

Fresh shrimp with heads on can typically be kept on ice for about 1 to 2 days. Keeping them on ice helps maintain their freshness by slowing bacterial growth. It's important to ensure the ice is replenished regularly and that the shrimp are kept at a consistent, cold temperature. For the best quality and safety, it's advisable to consume them as soon as possible.