Greek poets once wrote of these mythical creatures half horse, half sea monster on which the sea gods rode the seven seas. These creatures are indeed beautiful and mythical.
Seahorses, Sea Dragons and Pipe Fish all belong to the family Sygnathidae (pronounced sing-nath-I-dee) from the Greek words syn meaning together and gnathus meaning jaws or snout.
Seahorses belong to the genus, Hippocampus from the Greek words hippos meaning horse and kampos meaning sea monster.
All seahorses are fully marine species, although they can tolerate vast salinity ranges and can survive in some estuaries.
Seahorses are found world-wide, usually in shallow, coastal tropical and temperate waters, there are however some species that are found in water as deep at 60 meters.
There are 50 species of seahorse currently recognized. The greatest number of species is found in the Indo Pacific region. Australia has at least 14 species and Japan at least 7 species.
They have many predators and only a few forms of defense, their main one being camouflage, color changes to blend in with their environment. The other is immobility, their ability to remain motionless while their predators swim past.A basic biology: Seahorses are a fish, being a member of the Teleosts or bony fish group. They have a skeleton made up of bony plates, they use gills to breath and have an inflatable bladder to help regulate their buoyancy in the water.
Identification of seahorse species is done by examining distinctive markings and coloration, the number of tail rings, number of fin rays and by the shape of the coronet or crown, cheek and eye spines.
Seahorses propel themselves by a dorsal fin located on their back, which beats at around 70 times per minute. There are also two pectoral fins (located approximately where you might expect ears to be), which help them to maneuver. The seahorse's tail is prehensile (able to grasp), and is used to "hitch" to coral, grasses or other tank decorations. It is important to supply ample "hitching" posts for your seahorses so they do not get exhausted spending the whole day swimming and have somewhere to rest at night.
Seahorses have no teeth and therefore suck their food, which is small crustaceans or zoo-plankton, whole through their snout. Food sources must be sized according to snout size. The snout has a small opening at the very end though which food is sucked. If the food is too big it may get stuck or they simply will not be able to eat it.
An interesting feature of seahorses is that the male incubates the eggs. The female lays her eggs into the males pouch where they are fertilized and he gives birth to live young (see The Courtship Dance, Pregnancy and Birth for more details).
Most Seahorses become sexually active at about 6 months. They are, however, more likely to begin birthing at approximately 8 months of age.
Brood sizes can vary from 5 to 1600 depending on the species and size of the parents. Baby seahorses are called fry, but we like to call them ponies. The ponies vary in size at birth from 8 mm to 18 mm depending on the species.
The male seahorse is clearly recognizable by his brood pouch, while the female just has a rounded abdomen. If your seahorse is quite young and no pouch is visible you can determine the sex by looking for the anal fin. On females this is located quite low at the base of the rounded abdomen and on the males it is located higher up just above the opening to the brood pouch, the pouch slopes back towards the tail quite sharply in juveniles.
Male seahorses can be easily distinguished by the brood pouch on the male, while the female has a rounded abdomen.