2016 - By Koaw (Image updated 2020)
Whether you are a casual admirer of fishes, a serious enthusiast, or somewhere in between, it is very important to have these four basic anatomical directionalities memorized: anterior, posterior, ventral & dorsal. They also apply to most other animals within zoology.
The adjacent video discusses all you need to know to understand these anatomical directionalities!
Anterior - describes the direction towards to the front
the anterior region is also the cranial region, or the rostral region, where the head and nose are found.
Posterior - describes the direction towards the rear
the posterior region is also the caudal region (think of the caudal fin, also known as the tailfin)
Dorsal - describes the direction towards the back (spinal region)
the dorsal region is often described as the topside for fishes, as their backs are nearer to the surface of the water. But don't be confused! Think of a seahorse that has its head closer to the surface more often than not - the dorsal region of that fish faces laterally, or sideways, and is not "topside" like most fishes.
Ventral - describes the direction towards the belly
the ventral region usually holds pelvic and anal fins, and the urogenital and anal secretory passages (the cloaca and/or anus).
Distal - describes what is away from the body or body part in reference. Saying, “Possesses black dots distally on the caudal fin” is also another way of saying, “Possesses black dots on the end of the tail fin.”
Proximal - describes what is near the body or body part in reference. Saying, “This fish has red coloring proximal to the orbit” is also another way of saying, “This fish has red close to the eye bone.”