Hook: Size 10-20 (here, a size 14)
Thread: 6/0, black
Antennae: White closed cell packing foam (represents bubble or gills)
Tail: White closed cell packing foam (represents gills)
Rib: Wire through abdomen and thorax
Abdomen: Closed cell packing foam, colored with marker
Thorax: Peacock herl
The packing foam is tied down in one strip, leaving the two ends protruding. It's then colored with a black marker.