Pjh. Harrison et Dc. Sandeman, Morphology of the nervous system of the barnacle cypris larva (Balanus amphitrite Darwin) revealed by light and electron microscopy, BIOL B, 197(2), 1999, pp. 144-158
The central nervous system of the cypris larva of Balanus amphitrite consis
ts of a brain and posterior ganglion. The neuropil of the brain includes pr
otocerebral and deutocerebral divisions, with nerve roots from the protocer
ebrum extending to the eyes and frontal filaments, and nerve roots from the
deutocerebrum extending to the first antennae (antennules) and cement glan
ds. The neuropil of the posterior ganglion includes subesophageal and thora
cic divisions, with nerve roots from subesophageal divisions extending to t
he gut, and nerve roots from each of the six thoracic divisions extending t
o their corresponding thoracic appendage. The antennular nerve is the major
peripheral extension of the nervous system and is composed in part by effe
rent fibers that innervate setae on the antennules. The cyprid nervous syst
em is small, containing fewer than 2000 neurons, but is well organized for
coordinating a response to settlement cues.