“The whole layer of nephridial cytoplasm surrounding the radiating canals is 1 to 1.5 micron thick.”

“Nemerteans possess protonephridia consisting of multiciliated terminal cells, a ciliated nephridial duct and a nephridiopore opening at the epidermis.”

“Sensory and neurosecretory innervation of the nephridia is thus accomplished by a single neuron, which is thought to modulate nephridial performance.”