The Lined Seahorse (Hippocampus erectus) ranges anywhere from 2 through 230 feet deep in Marine habitats of the North and South American Atlantic coastlines The lined seahorse can usually be found clinging to aquatic vegetation such as seagrass or mangrove roots. This does not mean that sponges, corals, and floating sargassum are not out of reach of the Lined Sea Horse. While adults swim freely in the mid-water or stay within the habitat of seagrass, juveniles will be found swimming close to the surface of the water. The seahorse retreats into deeper waters during the winter months. For the most part lined seahorses range in color from gray, orange, brown, yellow, and red to black. There are characteristic white lines leading from the neck down to the tail which is why this fish's common name is “Lined Seahorse”. Seahorses do not have teeth and their long snouts accommodate their diet of small shrimp, very small fish, and plankton. The most unbelievable thing is the seahorse swallows their food whole. The seahorse lives for approximately one year and grows to a maximum length of 7.5 inches or 19 centimeters. Adult maturity is reached at lengths of 2.2-2.8 inches and males develop brood pouches at 5-7 months of age. While the tails of seahorses are normally seen to be curled up they can be straightened and curled again to hang onto objects for support, this is called a prehensile tail.

Seahorses have a courtship dance like birds of prey except Seahorses are suspended in water and they can hold tails while they swim snout to snout engaged in this courtship dance. The brood pouch that grows on the males is for the females to deposit eggs into where he will seal his pouch and fertilize the eggs, holding on to them so they hatch developing past the larval stage of their life cycle into the juvenile stage.

While the seahorse doesn't have very many natural predators and the only real purpose that humans have for collecting them is as souvenirs from the sea. This is the reason why this seahorse is protected under appendix II with CITIES, unregulated and uncontrolled commercial trade of this species has seriously affected the population of risk species. Outside of commercial trade the seahorses’ main problems are caused by their habitats being destroyed and pollution.