Often lives on rocks in association with the above anemones, remaining on the base of the column or foraging around on the oral disk picking up scraps. The shrimp seems immune to the anemone's nematocysts. They have been found in the guts of Pacific Halibut off Alaska.
As with other hippolytid shrimp, this species has no exopodites on its pereopods, the carpus of pereopod 2 is divided into 3-7 subunits (articles, a "multiarticulated carpus"), and a rostrum is present but if it has dorsal spines they are not movable. Lebbeus grandimanus has 7 articles on the carpus of its 2nd pereopod. It has one supraorbital spine. It has no exopodite on maxilliped 3, the rostrum is longer than the eye, the pleura of abdominal segments 2 and 3 are rounded, and leg 3 has no epipodite. The body is translucent and covered with bright yellow, blue, and red bands. Length to 4.5 cm.
Aleutian Islands, Alaska to Puget Sound