Lined Seahorse

The Lined Seahorse (Hippocampus erectus) is a medium-sized seahorse in the family Syngnathidae, found along the western Atlantic coast from Nova Scotia and the Gulf of Mexico south to Venezuela and Brazil. Adults typically grow to 12-17 centimeters, making it one of the larger seahorse species in its range. It displays considerable color variation, from black and grey to yellow or orange, and often shows fine pale lines across the neck, giving the species its common name. It is listed as vulnerable due to habitat loss and incidental capture, and is protected under international trade regulations for seahorses.

Identification features include:

• Medium-large seahorse, typically 12-17 cm in length
• Highly variable coloration, ranging from black, grey, and brown to yellow and bright orange
• Fine pale lines sometimes visible on the neck and head, the source of its common name
• Bumpy coronet on the head with small rounded knobs
• Long, slender snout and curled prehensile tail typical of seahorses It is distinguished from smaller relatives like the Dwarf Seahorse by its considerably larger size and from the Big-belly Seahorse by a slimmer body profile.

Lined Seahorses inhabit shallow coastal waters along the western Atlantic, from Nova Scotia in the north through the Gulf of Mexico, Caribbean, and south to Venezuela and Brazil. They are typically found in seagrass beds, mangrove roots, sponge and coral reef margins, and occasionally around floating sargassum weed, generally in less than 20 meters of water. They favor structurally complex habitats that provide both camouflage and secure anchoring points for their prehensile tails. This species tolerates a range of temperatures and salinities across its extensive latitudinal range, making it one of the most widely distributed seahorses in the Atlantic.

Lined Seahorses are slow, weak swimmers that rely on their prehensile tail to anchor to seagrass, coral, or other structures rather than actively pursuing prey or fleeing predators. They feed by ambush, sucking in small planktonic crustaceans and larval fish that drift within range of their tubular snout. Courtship involves an elaborate daily greeting dance between paired individuals, after which the female transfers eggs into the male's brood pouch for fertilization and incubation; the male later gives birth to fully formed young after several weeks. Many pairs are monogamous for at least a breeding season, and individuals often show high site fidelity to a small home range.