figure drawing of a horseshoe crab

“Horseshoe crab blood is bright blue. … Scientists used [the crabs’] clever blood cells to develop a test … which checks new vaccines for contamination.”
—Natural History Museum, London
upturned on the lab bench like a
melon, halved: we drew the
undulating outline of a horseshoe crab,
then sketched the legs tucked in
like seeds, studied the way her body
shelled itself. grasping legs / walking
legs / pushing legs. book gills, like
ribs, filled in her abdomen. we traced
the arc of carapace, the compound
eyes embedded in prosoma,
the hinge and spines. meanwhile,
on Atlantic beaches, horseshoe
crabs swam up to swarming shores,
tripped over their own arachnid
spawning: shells pressed close to
shells, gills held by the shallow swell
of waves against the sand. the water
balmy, dense with moonlit mating.
and meanwhile, too, horseshoe crabs
spilled their blue blood into glass jars
while strapped to the factory line,
their seedlike legs turned inward,
bodies tapped for miracle
coagulants. our miracle / their wane.
each vial brimmed with the drained-
blood promise of safety, blue
like the bay where the crabs were
sent back, once bled, to see
if they could still cling to the salt.