The longsnout seahorse is native to the Bahamas, Barbados, Belize, Bermuda, Brazil, Colombia, Cuba, Grenada, Haiti, Jamaica, Panama, United States (Florida and North Carolina), and Venezuela.

The longsnout seahorse has been found at depths of up to 180 feet (55 meters). Smaller longsnout seahorses tend to live in shallower waters, mature ones in deeper water.

Both sexes may have brown or white spots sporadically on their bodies that can change into pink or white during the courtship.

The Longsnout seahorse has an affinity for coral and sea grass beds. Males are usually orange, while the females are yellow.