Cages were constructed of 2.54 cm diameter white PVC pipe and 3-
way elbows in a cube-shaped frame that measured 0.5 m wide, 0.5 m
long, and 0.5 m high, circumscribing a benthic area of 0.25 m2. The
PVC frame was filled with stones to add weight. Black plastic (HDPE)
mesh (6.35 mm openings) was attached to all 6 sides of the frame
using plastic cable ties. The mesh allowed amphipods to move into
and out of the cage while preventing entrance or exit of all but the
smallest H. sanguineus,whichwould be unable to prey onmany amphipods.
Partial cages had only two sides of the frame covered with mesh,
as well as a top and bottom mesh panel.