This was part of the Louvre special exhibition at the museum and this is something of a significant piece of stone which dates to the fifth to seventh centuries. It was found in the Cemetery of Armant in Egypt and is part of the collections of the Louvre.
The symbolism is important as it’s an early piece of Christian art and it’s in really rather a decent condition. The fish represents the sea monster that gobbled up Jonah, whilst the cross is a reference to the Resurrection.
And, apparently, “the style of the carving, with its heavy outlines and textured patterns on the dolphin’s body, is characteristic of the expressive and often folk-like art of the Coptic Christian community during the Byzantine period.”