These are five rotated views of a living one-day-old fish embryo.  By this time the developing nervous system has formed the tube that will become the brain and spinal cord.  This tube has opened to form the brain ventricular system full of cerebrospinal fluid (CSF).  The fish cells are labeled red and the CSF is mixed with green dye. I needed to know the full shape and volume of the brain ventricular system and how it connects to the spinal cord very early in development, so that I can study the early functions of cerebrospinal fluid (CSF) in detail.