Beachcombing often yields glimpses into ocean life, but rarely gives you the full picture. A washed up moon snail shell fails to show you the incredible span on the snail’s body when it’s alive. A gull feather is not only a poor substitute for the whole bird, but it is often difficult or impossible to decipher the species of gull from which it came. Similarly, finding the shell of a mantis shrimp’s tail hardly does justice to the living creature, but it is interesting in that it can alert us to the organisms that might be living unseen beneath the water. This specimen was found washed up along with other objects in the wrack line behind a salt marsh in Bourne and belongs to Squilla empusa, a species of mantis shrimp found along the western Atlantic Ocean from Cape Cod to the Gulf of Mexico that can grow up to 10 inches long. Although fairly common in this area, they are very rarely seen because mantis shrimp burrow in soft sediment and only really emerge at night to prey on fish and other invertebrates.

Mantis shrimp are misleadingly named, as they are neither mantis nor shrimp. In fact, they’re so distinct from other crustaceans that they are given their own order: Stomatopoda. True shrimp, along with many crab species fall in the order Decapoda. The name mantis shrimp, however, comes from its pair of predatory mantis-like claws that it uses to capture prey (see picture from guide book above).

As an object I rarely come across while walking on the beach, I took this opportunity to take a closer look at the shape of the shell and its patterns while sketching it in my field journal (below). When drawing an object I’ve found in nature, I often try to note some of the more subtle features in text that might be difficult to capture with pencil.