How to Care for a Common Seahorse (Spotted Seahorse)

Without a doubt, with its "horse-like head" and erect body, the seahorse is one of the most recognized fish in the world. The seahorse "stands up" instead of lying flat as all other fish do. It propels itself through the water (very slowly) by vibrating its dorsal fin and steers with its tail. Perhaps the most interesting fact about this fish is that it is the male seahorse that gives birth. Seahorses have many natural predators that it evades with its ability to change its colors to blend in with almost any background.

Characteristics

Origin and Distribution

The common seahorse is a wide-ranging Indo-Pacific seahorse that inhabits waters from Indonesia to the Philippines, Pakistan, and India to southern Japan, Hawaii, and the Society Islands. Variations of this species reside in other areas outside of the Indo-Pacific region. Approximately 23 countries have confirmed the native presence of Hippocampus kuda ranging from Australia to China. Because spotted seahorses are popular ornamental aquarium fish, their captive distribution has become global.

In the wild, the baby seahorses either become pelagic and ascend into the plankton layer on the surface of the ocean or descend to the bottom and attach themselves to algae, corals or other stationary objects with their prehensile tails and start feeding on small crustaceans as they drift by in the current.

Not being strong swimmers, seahorses greatly prefer to inhabit the calmer shallow waters in mangroves, coastal seagrass beds, estuaries, coastal bays and lagoons, harbors, and rivers with brackish water where there is seagrass or marine algae for them to hold onto. Common seahorses which have, for one reason or another been unable to make it to the shallows near land, have been found up to 10 miles offshore floating in the plankton layer at the water's surface with their tails wrapped around debris or pieces of floating algae.

Colors and Markings

Common seahorses range in color from black to orange and yellow. Black individuals often have silvery stripes or other markings on the body, and sometimes unique yellow individuals can be dotted with red spots. A protective trait that this and many other seahorses have is the ability to change color to match its surroundings. It is not unusual for them to take on the coloration of a favorite object one has decided to adopt as a hiding place. 

Tankmates

Seahorses are generally solitary, except for their mates, which they like to remain in close proximity to. They are active during the day and generally avoid associations with non-pair individuals.

They may be kept with small, shy fish such as small gobies, pipefish, dragonets, and firefish. But aggressive, territorial, or fast-moving fish do not make good companions. Seahorses can be harmed by anemones and corals with stinging tentacles or corals that are large enough to consume them, such as brain corals. While sea fans, Acropora corals, and other branching corals may be safe for seahorses, they can be irritated or damaged by a seahorse that continually hitches to them. Crabs and clams may pinch a seahorse causing a wound that could lead to secondary infections. Small ornamental crustaceans may be consumed by the seahorses.

Habitat and Care

A 30-gallon aquarium is sufficient for a single pair. Add 10 gallons to the size of the aquarium for each additional pair. Since swimming is not its strong suit, the common seahorse does much better in an aquarium with a very little current. Spray bars may be used to create gentle flow while eliminating stagnant areas in the aquarium. Seahorses use their prehensile tails to hitch to branching live rock, algae, or artificial decorations.

It also seems to do much better in a taller aquarium where it can drift up and down and attach to and hold fast to objects.

Diet

Seahorse hitch onto an object and wait for its food to drift by, which it sucks up and swallows whole since seahorses do not have teeth. Captive-bred seahorses are accustomed to frozen mysis shrimp, making them a smart alternative to their wild-caught counterparts. They will also feed upon amphipods and other small crustaceans found in live rock. They will also accept vitamin-enriched adult brine shrimp, but this should not make up a majority of their diet. They are slow, deliberate feeders and prefer two or more small feedings per day.

Seahorses should be fed live, vitamin-enriched frozen (if they will take it), or freeze-dried mysis shrimp. Seahorses should be fed several times per day with food available for 20 to 30 minutes per feeding. Wild-caught seahorses may be slow to accept frozen or freeze-dried mysid shrimp as food, to begin with, and may have to be fed live foods until they are weaned onto prepared foods. Tank-raised seahorses are normally trained to accept frozen or freeze-dried mysid shrimp at an early age and will make the transition to your tank much more easily than wild-caught specimens.

Sexual Differences

As males are the pregnant partner in seahorse mating, males that have reached sexual maturity have a brooding pouch. This is where the male carries the fertilized eggs. Breeding occurs year-round, so, a rounder belly pouch can signify a male. Around the breeding time, the male begins by changing its color patterns and does a dance around the female. It also produces clicking sounds with its coronet, a crown-shaped piece of skin or horn-like structure at the top of its head.

Breeding

Seahorses choose a mating partner for life. They maintain a monogamous relationship with one partner until that partner dies at which time the remaining seahorse may search out a new mate. This seahorse becomes fully mature at about 14 weeks and can reproduce at that time.

Not only does the male seahorse gives birth to the brood, but the male is responsible for attracting the female. After an elaborate courtship period, a dance, and intertwining of tails, the wooed female uses an ovipositor to insert her eggs into the male's pouch. It is in this brooding pouch where the eggs are fertilized and attach to the wall of the pouch. Placental fluid removes waste products and supplies the eggs with oxygen and nutrients as they mature into baby seahorses. At the end of 20 to 28 days of pregnancy the male goes into labor, typically at night when there is a full moon. The baby seahorses are then ejected from the male's pouch. The brooding pouch may contain anywhere from 20 to 1,000 fertilized eggs.

More Pet Fish Breeds and Further Research

If the common seahorse appeals to you, and you are interested in maintaining a saltwater aquarium, check out other saltwater fish that may be compatible with seahorses. 

• Mandarinfish (dragonets)
• Firefish
• Gobies

Check out additional fish breed profiles for more information on other freshwater or saltwater fish.