Seahorse

These horse-shaped head-like looking bony fish were much debated over by scientists for years, if they could even be classified as fish. But they are classified as bony fish as they have a swim bladder and gills. There are believed to be around 45 to 55 species of seahorses in the world but it’s difficult to distinguish them, because they do not vary much from one species to another.

Seahorses have a relatively short lifespan of 1 to 4 years. They are not known for their fast-swimming style, these fish do however have an impressive camouflage capability to blend into their environment. Their shape, size and color changing capacity are perfect for hiding in plain sight. Seahorses use their tails as anchors to hold onto corals, seaweed and mangroves, gently swirling with the tight of the ocean, blending into their environment almost perfectly. As mentioned before, they are not fast swimmers, even though their fins move rapidly, up to 35 times a second. They prefer to stay in one place, sometimes even days in a row, hanging on to the same coral.

In general they are plankton eaters but also feast on small crustaceans and algae. An interesting fact is that seahorses do not have a stomach and therefore need to eat up to 50 times a day to maintain their fast metabolism. They have a spectacular courtship ritual, that looks like a dance in which they change colors while grabbing each other with their tails. Unique to seahorses is that the males carry the fry until they are self-reliant. Females insert their eggs into the male’s brood pouch. One pregnancy can produce up to 300 young that feed themselves on the yolk of the egg. Another spectacular feature to witness is when males ‘’give birth”, contorting their bodies into contractions, shooting out the young seahorses for minutes at a time, sometimes even hours.

In the beginning they were difficult to keep alive in an aquarium mainly because most of them were wild caught, not eating in captivity and very susceptible to diseases. But nowadays captive bred specimens are more easily kept because they will take hand-fed food. Seahorses have an exoskeleton (bony fish) covered with some sort of skin instead of scales, that is why they are more susceptible to bacterial infections and diseases. In aquariums you will mostly find the lined seahorse (Hippocampus erectus) and the common seahorse (Hippocampus kuda). A perfect nano species is the dwarf seahorse (Hippocampus zostera) because of its tiny size, growing to a maximum less than 5 cm. Keep them in pairs or small groups, they feel safer and less stressed that way.