Northern Lined Seahorse


Scientific Name: Hippocampus erectus

Fish Care

Fish Diet: Small Crustaceans
Aggressiveness: Non-Aggressive
Reef Safe: Yes
Minimum Tank Size: 30 Gallon
Max Size:
Relative Care: Hard


The Northern Lined Seahorse (Hippocampus erectus) are commonly found in the trade. There are differences between the erectus species found in other regions. For example, the Southern Lined Seahorse does not have pelagic fry and can tolerate warmer temperatures than the Northern Lined Seahorses. The tank temperature should not exceed 75 degrees Farenheit to keep these seahorses healthy. Besides sensitivity to temperature, I find the Northern Lined Seahorse to be quite hardy and easily trained to take prepared foods. Males can get quite large, maxing at about 5-6 inches. They will breed regularly in captivity. Because of the pelagic stage of the Northern Lined Seahorse fry, they can be a bit challenging to raise and require special systems. They need to be fed twice a day to truly be happy (an undertaking that many aquarists are not willing to do). Despite what you may read, offering a live treat like mysis shrimp once in a while is good practice. They will still maintain eating frozen foods even when offered live foods. The picture above is a female. You can sex them by looking for the pouch. Males have a pouch for holding the eggs and females do not.