Gill receptor arrays in the horseshoe crab (Limulus polyphemus).
The branchial warts on the endopodites of the gills are covered with goblet-shaped cuticular appendages, whose internal structure shows them to be chemoreceptors. The innervated goblets have a cuticular tubule that connects an external pore through their hollow interior with the epidermal sensillum. Associated sensory neurons give rise to small axons that pass through a synaptic plexus below the epidermis. The sense organs seem specialized for sampling the exhalent water current.
D000818:Animals; D001369:Axons / Q000648:ultrastructure; D002628:Chemoreceptor Cells / Q000648:ultrastructure*; D003712:Dendrites / Q000648:ultrastructure; D005880:Gills / Q000294:innervation* / Q000648:ultrastructure; D006737:Horseshoe Crabs / Q000648:ultrastructure*; D007365:Intercellular Junctions / Q000648:ultrastructure; D012867:Skin / Q000648:ultrastructure; D013569:Synapses / Q000648:ultrastructure