An excellent diagram of seahorse anatomy can be found at
A seahorse uses it's dorsal fin to move forward and it's pectoral
fins for control turning and steering.
The front of a male seahorse is gently rounded with the brood pouch below
the abdomen. The female has a sharper angle at the bottom of the abdomen
going directly to the top of the tail. The anal fin can also be a clue to
you will find it at the juncture of the abdomen and the tail of the female,
the male anal fin is between the abdomen and the brood pouch but can be
difficult to see as the male tends to keep the anal fin tucked in close.
Each eye moves independently so the seahorse can actually look in two
directions at the same time. It can be a bit disconcerting when you first
see them do this.
The coronet (a raised "crown" on the top of their head)
is nearly as distinctive as a human thumbprint and the shape is an
important clue as to species of the seahorse. Many seahorses in
nature have cirri which are filaments of skin sticking out from their body.
Cirri are used to blend with surroundings and often disappear in captivity but
Seahorses change color. This is still being studied but it
appears that each seahorse has a range of available colors based on species and
heredity. Most will have a "base" color which is somewhat stable but can
be changed entirely. Our yellow kuda was mostly black when we bought her.
Most will exhibit lighter colors for greetings and mating. Color changes
are also associated with surroundings, health, and stress levels but the details
are not clearly understood.
Seahorses have no teeth and swallow their food whole, they also lack a
stomach and food is digested in the intestines. When a large
quantity of food is eaten in a short period of time, the food can be
pushed through without digestion occurring. For information on
feeding please see the Nutrition page.