With their unusual shape and unique take on parenting, there's nothing "of course" about the seahorse
A longsnout seahorse with unique black spots.
In the realm of beloved creatures, the seahorse ranks high on the list. Though it seems more suited to exotic seas and the South Pacific, it can be found globally in warm and temperate oceans, as well as nearshore waters like our Indian River Lagoon. Their whimsical nature sparks imaginations, including those of artists who create all manner of artworks to celebrate our fascination with them and their universal appeal.
The most defining trait of the seahorse is its neck, a feature it shares with no other fish. It connects the seahorse’s equine head and elongated snout to its upright body, its single-most recognizable characteristic. This body plan, unique in the fish world, is likely responsible for its many one-of-a-kind modifications. But while it would be tempting to skip first to these oddities (and there are many), it might be best to start with the characteristics of common fish that they are missing, which explain a lot about how they have adapted.
Seahorses don’t have a sense of smell — the ability to interpret the scent molecules that waft on currents through the water. They do not have teeth. And although they have dorsal and pectoral fins that work very hard to keep them afloat, seahorses lack both pelvic fins and a caudal fin — the “tail” fin that is responsible for forward propulsion in most other fish. Finally, they do not have a stomach, necessitating that they eat almost nonstop.