It’s that time of year when you see jack-o’-lanterns on porches and skeletons hanging in windows… but did you know even the bay is ready for Halloween with little creatures called skeleton shrimp wandering around?
If you have ever looked really closely at a sponge or a dock piling in the bay, you may have noticed tiny, long-limbed creatures reaching out that resemble a miniature praying mantis. These minute creatures are called skeleton shrimp. Not because they spookily haunt the waters of the bay, but because their long, threadlike bodies resemble skeletons, even though they don’t have any bones. They are not actually shrimp but are amphipods and move around using front and back limbs like an inchworm. To see how they move, check out this great video of these dancing skeleton shrimp found in the Coastal Bays!
These spooky critters are omnivores, which means that they eat plants and animals, and eat anything small enough to grab that passes by, whether it is alive or dead. They feed by holding onto a sponge or vegetation with their lower limbs and then reach out with their gnathopods, limbs specialized for feeding and defense, to grab hold of things floating in the water. Don’t worry about being grabbed by one though, because they are only about ½ to 2 inches long!
The females carry the fertilized eggs around in a brood pouch until the young hatch out. When the juveniles emerge from the egg, they look like miniature adults. Similarly, to the praying mantis, which they resemble, the female will sometimes kill the male after mating using venom from a claw in their gnathopod.
Skeleton shrimp are found worldwide in marine environments and the ones we have here in the Maryland Coastal Bays are native. So, the next time you happen to be looking at vegetation in the bay or the underside of a dock, look extra closely because you might be lucky enough to see a tiny skeleton shrimp! And a picture of one would make a spooky Halloween decoration!
About the Author – Archer Larned, PhD
Archer Larned, PhD, is the Coastal Bird Habitat Coordinator at the Maryland Coastal Bays Program. She primarily monitors a floating platform for nesting Common Terns during the summer months. She also surveys other colonial nesting waterbirds and analyzes data.