Common Grass Shrimp
Palaemonetes pugio

The common grass shrimp has a delicate, nearly transparent body with a distinctive serrated “horn” over the eyes. It lives in shallow waters throughout the Chesapeake Bay and its rivers.

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The common grass shrimp grows to 1.5 inches longs, with a nearly transparent body and a serrated "horn" over its eyes. (Photo courtesy Astro/iNaturalist CC BY-NC)

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Appearance

The common grass shrimp has a segmented, nearly transparent body that is compressed on either side. It has a pointed, serrated “horn” that extends over its eyes. Its first two pairs of walking legs have claws. The shrimp grows to 1.5 inches in length.

Feeding

Grass shrimp forage for worms, algae and tiny crustaceans.

Predators

Small fish such as sunfish and killifish feed on grass shrimp.

Reproduction and Life Cycle

Usually spawns in summer, when water temperatures warm. Females must molt before mating. The female carries her eggs in a brood pouch, visible through the shrimp’s transparent body. Eggs hatch into free-swimming larvae after 12-20 days. Larvae go through several developmental phases over the first 1-2 months of life. Grass shrimp live approximately one year.

Did You Know?

  • The common grass shrimp is the most abundant of the four species of grass shrimp known to live in the Bay.
  • They often carry a parasitic isopod, Probopyrus pandalicola, which looks like a bulge near the shrimp’s gill area.
  • Grass shrimp are an important ecological indicator of human impacts on estuaries and other water bodies.

Sources and Additional Information

Tags:
Invertebrates Arthropods Open & Shallow Waters