Latin name

Hippocampus zosterae

Other names

Hippocampus zosterae

Identification

There are often small skin growths called tendrils that resemble algae. The head is at right angles to the body and Dwarf seahorse swims upright, using the dorsal fin for movement and the pectoral fins for control. The seahorse can live up to 2 years, but most commonly lives about 1 year.

Sailing speed

The slowest moving fish, its maximum speed is about 1.5 metres (5 feet) per hour.

Features of fish fins

This species has 10 to 13 dorsal and pectoral fin rays and 9 to 10 rings on the body.

Fish colouring

Mostly white in colour, but can range from reddish, brown, yellow and green. Can be found in beige, yellow, green and black, can also have white spots, dark patches or protrusions and is well camouflaged, the colouring usually matching the gorgonian on which it is usually found. The dwarf seahorse can change colour. It has been observed to change colour for various reasons such as camouflage, response to attack, disease or during mating.

Distribution

Found in the western tip of the Atlantic Ocean, specifically the coastal areas of the Gulf of Mexico, the Bahamas, Bermuda, the Florida Keys, the east coast of Florida, Old Tampa Bay, Lemon Bay, Pensacola and Texas.

Habitat

Marine, bottom-dwelling, non-migratory species. Depth range 0-10 m. Subtropical; 33°N to 17°N, 99°W to 64°W. Almost entirely restricted to shallow-water algal microhabitats, especially when associated with zostera algae. Most abundant in bays during periods of high salinity, on coral reefs, in floating vegetation and between roots in mangrove swamps.

Size

Grows to between 2 and 2.5 cm (0.8 and 1.0 inches) on average, with a maximum length of 5.0 cm (2.0 inches).

Behavior

They often live in pairs, sometimes alone. The males are rather sedentary, occupying a small home range of about 1 square metre, while the females roam the territories of other males, which are about a hundred times larger than their own. They are diurnal. 

Food and feeding habits

An ambush predator that feeds on live prey, including small crustaceans such as amphipods, small shrimps, other small invertebrates and fry. Once a target is identified, the hunter grabs it and sucks it up through the snout. The food passes quickly through the digestive system, resulting in poor nutrient absorption. This is why seahorses need large amounts of food to survive. These creatures can eat up to 3,000 brine shrimp a day.

Reproduction

The offspring are carried by the male, he competes for access to the female. The males will wrestle with their tails, turn their heads towards each other and make clicking noises as they compete for access to her. They perform an eloquent courtship dance that begins each morning and continues until copulation.

Females initiate courtship behaviour by entering the male's territory. Once she enters his territory, the male initiates the actual behaviour. During the first phase of courtship, the male and female change colouration and alternate shivering. This phase lasts for one to two hours in the morning before copulation. The following phases of courtship behaviour take place on the day of copulation. During the second phase, the female displays a pointing posture with her head pointing upwards. The male responds to the female's pointing by jerking and swaying. In the third phase, the male adopts a pointing posture in response to the female's pointing. Finally, in the last phase of the mating behaviour, the pair will rise several times in the water column. The male presses his tail against his body and finally the pair intertwines their tails. The female inserts her ovipositor and transfers the eggs to the male's brood pouch during the final ascent of the water column. After oviposition, the male swims back and forth to deposit the eggs in his pouch.

Males carry 3 to 55 future offspring in their brood pouch for about 10 days before releasing them into the wild. Newly born pygmy seahorses are 7 to 9 mm long, while the eggs in the pouch are about 1.3 mm in diameter.

Although females can technically mate with several males, seahorses form strictly monogamous pairs for the entire season, which is rare among fish species. Females remain faithful throughout their pregnancy, returning to the male's territory each day for an early morning greeting. During the greeting, the pair changes colour and dances together for about 6 minutes. Adults have several reproductive cycles throughout their lives.

Dwarf seahorses reproduce within 4-20 hours after the young are released from the brood pouch. This can occur throughout the breeding season. The breeding season begins in mid-February and ends in late October, depending on day length and water temperature.

Development

Each larva grows and develops in its own pocket of tissue surrounded by a network of blood vessels. The brood sac is similar to a "pseudoplacenta": after the eggs are laid, the walls of the sac thicken and become more porous. The sac provides protection, oxygen, food and waste removal. During their growth in the brood pouch, the dorsal fin rays develop first, followed by the anal fins. This is followed by the development of the mouth apparatus, which does not function until the larvae are released from the brood pouch. Compared to the adult seahorse, brood pouch offspring have a rounded tail instead of a tetrahedral tail, a broader and shorter snout, a dorsal fin closer to the tail and pectoral fins closer to the neck. 

Time of year and water temperature have a disproportionate effect on the sex ratio of developing seahorses. Once the offspring are released into the environment, they become completely independent of their parents. They are able to swim and feed immediately, but their poor swimming ability and high predation rate reduce their survival rate. Growth of H. zosterae is relatively rapid, especially during the summer season; both males and females are fully grown in 3-4 months. The sexual maturity of the male can be determined by the presence of a brood pouch.

Fishing

The primary business of several fisheries in Florida is the capture and trade of dwarf seahorses.

Relationship with a person

Popular on the aquarium market. Chinese medicine is one of the largest consumers of seahorses.