Sensory morphology in the antennae of the cephalocarid Hutchinsoniella macracantha (Crustacea)
The first antenna of Hutchinsoniella macracantha is a 6-segmented, uniramous appendage carrying 1 aesthetasc and 22 setae (or sensilla). The second antenna is biramous and has approximately 80 setae. The sensory cells of the first antenna are arranged in 3 clusters in the first and second segments; one cluster serving the aesthetasc (approximately 130 cells), one the 11 setae of the sixth segment