Alaska Bay Shrimp

How to Distinguish from Similar Species: Crangon nigricauda has a shorter antennal scale and spine and is much less slender.

Biology/Natural History: This shrimp is one of the crangonids I most commonly find in 100 m depth trawls in the San Juan Channel. Crangonids are often parasitized by bopyrid isopods such as Argeia. Crangonids are active predators, eg. on polychaetes. In Puget Sound some shrimp appear to be hybrids between C alaskensis and C. nigricauda.

Crangonids often live on sand, which they often burrow into.

Geographical Range: Bering Sea to San Diego, CA

Depth Range: Intertidal to 275 m. This species seems to be found more often in deeper, shelf waters than near the intertidal zone.

This shrimp has the typical extremely short rostrum characteristic of many crangonids. The carapace is smooth and has a median dorsal spine but no submedian spine. Abdominal segment 6 has no longitudinal dorsal carinae but the underside does have a median sulcus. Abdominal segment 5 has no spines on the upper posterolateral margins. The inner flagellum of antenna 1 is longer than the outer flagellum. The antennal scale is more than twice as long as wide, has a narrow lamella, and its spine is as long as or longer than the lamella. The scale is shorter than the telson. Length to 6.5 cm.