There are approximately 54 species of seahorses in the oceans. Are seahorses fish or crustaceans? They swim upright with the help of their dorsal (back) fins. These creatures live in shallow waters worldwide, except in colder areas. Seahorses aren’t just different from other fish in their external appearance, either: they’re also ridiculously poor swimmers. Seahorses breathe using gills, have a swim bladder to control their buoyancy, and are classified in the class Actinopterygii, the bony fish that also includes larger fish like cod and tuna. Seahorses are a type of fish that get their name from their horse-like heads. Sea horses are classified as a fish. Seahorses have clearly figured out how to make the most of their movements. They are the slowest-moving of all fish species because of an impeccably tiny fin in the middle of their backs being the only way to propel themselves. baby seahorses who are also called fry eat plankton and other fishes small enough to swallow eat larvae as well. Seahorses also have interlocking plates on the outside of their body which covers their spine made of bone. There are more than 70 seahorse species around the world. I suppose you think there might be some confusion due to the fact that the sea horse male give live birth from eggs that the female deposited into his poch when mating? A seahorse is a fish. Seahorses are fantastic creatures to observe in aquaria, and with a little advanced planning and research, they are not much more difficult to keep than many other fish. Yes the seahorse is a kind of bony fish (Osteichthyes) in the phylum Chordata, and the genus Hippocampus. And who would have thought that such gentle, slow creatures could be … Seahorses also lack pelvic fins - which gives them the appearance of a lovely proud chest - and the researchers found that they’re missing the gene tbx4, which is a regulator of limb development in both fish and mammals alike.