Explorer's
    Guide

 

Oceanic Seahorse
Scientific Name: Hippocampus kuda

The oceanic seahorse, like all seahorses, reproduces differently than any other fish. Instead of the female bearing the young, it’s the male. Male seahorses carry their young in a pouch on the front of their body until the young hatch. These young seahorses are miniature replicas of their adult parents.


Region: Philippines

Appearance
This fish is well camouflaged among seagrass and soft corals. The oceanic seahorse has a mottled base color of combinations of dirty yellow and beige with shades of light red and brown. There are black to brown spots and sometimes even bands. Stretched out this seahorse is 11.8 inches (30 cm).

Seahorses have a long tube-like snout and long slender body, protected by bony plates. The prehensile or gripping tail is long and curls up underneath the fish. The head bends downward and the snout sticks out far in front of the body. Unlike most fish, the oceanic seahorse lacks caudal fins or tail fins and anal fins or fins on the belly near the tail. This seahorse does however have pectoral fins that look like ears and a dorsal fin or fin on the back.

Habitat
Seahorses live in areas where they can easily hide. Not equipped with large fins for swimming fast, seahorses use their slender bodies to slip into tiny cracks and crevices out of reach from danger.
The oceanic seahorse is mainly found in the seagrass and algae areas of estuaries and seaward reefs. They will also holdfast to branching corals, featherduster worms, or the arching underwater roots of mangrove trees. Unlike most seahorses who stick close to shore, the oceanic seahorse can also be found floating in open water and attached to drifting Sargassum weeds, which is a leafy golden brown algae that floats freely throughout the ocean with small air bubbles or bladders. This seahorse can be found to depths of 226 feet (68 m).

Range
The oceanic seahorse lives in the warm parts of Pacific Ocean and the Red Sea.

Diet
This seahorse feeds on tiny shrimp, other small crustaceans, and phytoplankton or tiny plants, and zooplankton or tiny animals. With a straw-like mouth, this seahorse slurps up any animals drifting nearby. The force of the suction can be so great, the noises can be heard from far away.

Reproduction
Seahorses are sexually dimorphic, which means the males and the females look very different. The tails of the males are much longer than the females’ tails. The snouts of the males are longer as well.

Seahorse reproduction is one of the most unique methods in all of the animal kingdom. Seahorses pair up and mate for life. Their mating ritual begins with a courtship routine. The male starts it by dancing around the female. He produces clicking sounds with his skull and both the male and the female change colors. Moving to a coral, sponge or piece of seagrass, the pair takes hold with their tails, wrapping around it. They will venture from the meeting spot to float across the ocean bottom with their tails entwined. Eventually, the female stretches out her body, pointing her tail down and nose up toward the surface. At the same time, the male pulls his tail back and pumps water in and out of a pouch on his belly. After rinsing out his pouch, the male lengthens his body and pairs up with the female belly to belly. The couple locks together when the female puts her ovipositor or tube that deposits eggs into the male’s pouch. From the tube, a string of large pear-shaped sticky eggs go into the pouch. Once the eggs are safely inside, the male releases sperm, fertilizing the eggs. After all the eggs are inserted, the male floats down to the bottom, swishing back and forth to settle the eggs down into the bottom of the pouch.

The morning after the male is pregnant, the pair meets and performs the first few stages of their mating ritual. They will change colors, dance around each other and wrap their tails together. After this morning greeting, the female leaves the male for the rest of the day and returns the next morning for a repeat performance.

The father gives birth in the early hours of the morning, often starting in the dark. Contracting his pouch, the male helps the young find there way out. Once the fry or baby fish are born, they are left to fend for themselves. Neither parent cares for the tiny young who are only (6 to 12 mm) long. The day that the male gives birth, the female will return to deposit a new batch of eggs. There’s no rest and recuperation for the pregnant father.

Often found in mangrove swamps, oceanic seahorses seek shelter between the branching roots of mangrove trees to mate and safely leave their young.

Endangered

A species or group of organisms that is in danger of extinction or disappearing from the face of the earth in the near future if its situation is not improved.

Threatened

A species that can be found throughout its natural range but is declining in number and may become endangered in the absence of special protection efforts.

Vulnerable

A species that is not declining in number but is of special concern because it is sensitive to pressure by particular human activities or natural events.

Stable

A species that is not declining in number and is not sensitive to pressures by human activities or natural events.

Threats and Management
Seahorses are threatened on a global scale for three reason: the traditional Chinese medicine trade, pet trade, and arts and crafts. Over 20 million dried seahorses were taken from the ocean in 1995 for the Chinese medicine trade. People of Asian descent, as well as others, use traditional Chinese medicine to treat sickness. Oceanic seahorses are sought after for this trade, which contributes to their vulnerable status.

Hundreds of thousands more are taken for the pet trade to be sent on to pet stores, making their way into home aquariums. Oceanic seahorses are a popular fish with home aquarium hobbyists. Without a great deal of experience, oceanic seahorses are hard to keep alive, in part because they are very picky eaters and need to eat live food.

If you go to your local craft store, or even shop in department stores and variety stores, you can often find packaged dried seahorses or see them used in trinkets and ornaments. Hundreds of thousands of seahorses are sold to stores for arts and crafts. Combining all three of the above mentioned uses adds up to a lot of seahorses. While seahorses reproduce frequently, the do not produce large litters and the young are very vulnerable to getting eaten by predators.

The Shedd Aquarium helps save baby seahorses. The Shedd Aquarium supports a conservation organization called Project Seahorse. Scientists and community workers teach local villagers in the Philippines and elsewhere to study seahorse populations and establish ways to take these fish without exhausting the entire population. In one program, pregnant seahorses are placed in underwater cages. The baby seahorses can slip out of the cage and into the wild right after they’re born. This allows the young seahorses to replenish the supply of seahorses on the reef or in the seagrass. After giving birth, the adults in the cage can be sold, allowing the villagers to maintain a steady income while keeping the seahorse population stable.

Protected areas or reserves for these little animals also have been put into place and allow villagers to collect seahorses without exhausting entire populations.

Here in Chicago our gift shop sells sustainable crafts from Philippine villages. This provides villagers with a source of income that doesn’t depend on the reef.

Did You Know?
Greek poets use the word Hippocampus to describe a mythical beast which carried sea gods on their backs. This creature was half-fish and half-horse.

Seahorses are thought to communicate by rubbing parts of their skull together to produce a loud clicking noise. When courting, the clicking becomes louder and louder.

Seahorses may be found with snipped off tails, narrowly escaping an encounter with a hungry crab.

References
Web Sites:
NOTE: The following Web sites are not maintained by the John G. Shedd Aquarium and will open in a new browser window.

Fishbase:
http://filaman.uni-kiel.de/Summary/SpeciesSummary.cfm?
ID=5955&genusname=Hippocampus&speciesname=kuda


Print Publications:
Debelius, H. 1999. Indian Ocean Reef Guide. Frankfurt, Germany: IKAN. 321p.
ISBN# 3-9317-0267-7.

Lourie, S.A., Vincent, A.C.J., and Hall, H.J. 1999. Seahorses. An Identification Guide to the World’s Species and Their Conservation. Mitcham, Surrey: Dorling Print Limited. 214p. ISBN# 0-9534693-0-1.

Myers, R.F. 1999. Micronesian Reef Fishes. Barrigada, Guam: Coral Graphics. 216p.
ISBN# 0-9621564-4-2.

Perrine, D. 1997. Mysteries of the Sea. Lincolnwood, Illinois: Publications International, Ltd. 312p. ISBN# 0-7853-2430-5.

Vocabulary Words

Anal fin – the fin on the belly behind the anus.


Camouflage – An animal that conceals itself by disguise or protective coloring, making it indistinguishable from the surrounding environment. To hide from an enemy by making oneself appear to be part of the natural surroundings.


Caudal – Having to do with the end or tail of an animal. The tail fin.


Crustacean – Animals from the class Crustacea—like lobsters, crabs, shrimps, and barnacles—that are primarily aquatic and characteristically have a segmented body, a hard exoskeleton, and paired jointed limbs.


Dorsal – The back of an animal. The large fin on the back of a fish.


Extinction – An organism that has not been present on the face of the earth for over 50 years.


Fry – A baby fish.


Mangrove trees – Tropical salt tolerant trees that live along the ocean’s shoreline. They have stilt-like roots and stems, forming dense thickets where many animals, especially young reef creatures, seek a safe refuge.


Organism – A living thing.


Ovipositor – An organ some fish have which is a tube-like structure that is usually concealed but sometimes extends outside the abdomen with which the female deposits eggs.


Pectoral – The paired fins on the sides of a fish behind the gills.


Pet trade – An industry or business in which animals are taken from the wild and sold to pet stores, zoos, and aquariums.


Phytoplankton – Microscopic plants that float at the mercy of the ocean currents.


Prehensile – Adapted for seizing, grasping, or holding, especially by wrapping around an object.


Sargassum weed – A leafy golden brown algae that floats freely throughout the ocean with small air bubbles or bladders. This algae can house many small animals like small fish, worms, shrimp, crabs and jellies. Some of these animals only live within the safe confines of the Sargassum weed.


Sexually dimorphic – In animals when each sex is distinctly different. Males look very different than the females.


Species – A group of organisms capable of breeding and producing fertile offspring; organisms that share the same gene pool.


Traditional Chinese medicine – A form of medicine practiced predominantly in China, Hong Kong, Taiwan, and Singapore. It is based on two counterpart, yin and yang. People get sick when the balance between yin and yang shifts. Natural elements, such as seahorses and other sea creatures, are used to heal disease.


Zooplankton – Microscopic animals that float at the mercy of the ocean currents and have weak swimming ability.

Oceanic Seahorse
Oceanic Seahorse