INNERVATION OF THE DORSAL ORGAN OF THE SHRIMP MACROBRACHIUM-INTERMEDIUM (DECAPODA, NATANTIA)

The dorsal organ is a sensory system found widespread among the Crustacea. Seen externally, it is typically composed of a pore (or a small group of pores) centrally placed with 4 sensory plates arranged, often equidistantly, around it. It lies in the midline of the carapace. The innervation of this organ in the natantian Macrobrachium intermedium is shown to originate at the tritocerebrum of the brain and to follow a ventrolateral course along the rim of the antennular muscles in the thorax before turning medially along the edge of mandibular adductor muscles and linking with the dorsal organ.