Seahorse

A seahorse (also written sea-horse and sea horse) is any of 46 species of small marine bony fish in the genus Hippocampus. The name comes from Ancient Greek hippókampos, which means "sea monster" or "sea animal" because these creatures look like tiny horses. Seahorses have a head and neck that resemble a horse, along with a special bony armor that protects them.

These unusual fish stand upright and have a curly, flexible tail that helps them hold onto seaweed and coral. This tail is called a prehensile tail. Seahorses, together with pipefishes and seadragons, belong to a family of sea creatures known as Syngnathidae. Their unique shape and behavior make them some of the most fascinating animals in the ocean.

Evolution and fossil record

Seahorses are special types of pipefish. We know this from their body structure, molecules, and genes. Fossils of seahorses are rare, but the best-known fossils are from the Marecchia River in Italy. They are about 3 million years old. Even older fossils from Slovenia are about 13 million years old.

Studies show that seahorses and pipefish split apart during the Late Oligocene period. Changes in shallow water habitats, caused by tectonic events in the western Pacific Ocean, may have helped this change happen. Their upright shape helps them catch small shrimps from farther away than pipefish.

Description

Seahorses are small fish that live in the sea. They are about 1.5 to 35 centimeters (0.6 to 13.8 inches) long. They look like tiny horses, with bent necks and long noses. Most fish have scales, but seahorses have thin skin with bony plates that protect them.

Seahorses swim up and down using a dorsal fin. This makes them different from their relatives, the pipefish, who swim sideways. They have special fins near their heads to help them turn, and a prehensile tail that wraps around things for support. Seahorses are good at hiding. They can change a little to look like their surroundings. Their eyes can move on their own, like a chameleon’s, and they use their long noses to catch food.

Habitat

Seahorses live in shallow tropical and temperate salt water around the world, from about 45°S to 45°N. They like quiet places such as seagrass beds, estuaries, coral reefs, and mangroves. Some species are found in Pacific waters from North America to South America, while others live in the Atlantic, like from Nova Scotia to Uruguay. The dwarf seahorse, H. zosterae, lives in the Bahamas.

In European waters, seahorses have been found in places like the Thames Estuary. Two species live in the Mediterranean Sea: the long-snouted seahorse H. guttulatus and the short-snouted seahorse H. hippocampus. Males usually stay in a small area of about 1 m², while females move around more.

Feeding habits

Seahorses use their long snouts to eat small crustaceans like mysid shrimp and other tiny invertebrates, as well as sometimes larval fish. They wait quietly, hidden with great camouflage, until their food is close, then quickly grab it. Because they don’t have a stomach and move slowly, seahorses need to eat often to stay strong. They hold on to seaweed, coral, or other objects with their special prehensile tails to stay in one place while they hunt.

Reproduction

The male seahorse has a special pouch on the front of its tail where it carries the young. When it is time to have babies, the female places her eggs into the male's pouch. He keeps them safe for about two weeks until the baby seahorses are ready to swim. After they are born, the male can be ready for more eggs very quickly.

Before having babies, seahorses go through an interesting courtship. They change colors, hold tails, and dance together. This helps make sure they are ready to mate. The female puts her eggs into the male's pouch, where they develop safely until they are ready to join the ocean.

Threats of extinction

Seahorses face threats that could put them at risk of disappearing. We don't know exactly how many seahorses are left, but their homes like coral reefs and seagrass beds are being damaged by human activities. Many seahorses also get caught accidentally in fishing nets.

Conservation

Protecting seahorses is important to people around the world. Their homes, including seagrass beds like Posidonia oceanica and Zostera marina, mangroves, and coral reefs, need to be preserved to help these special fish survive. Seahorses are often used in conservation campaigns and community science projects because they are popular and attract people's attention. However, studying them is difficult because they are hard to find and their groups are small and spread out. Understanding where they live and what threats they face is key to protecting them in the future.

Aquaria

Many people like to keep seahorses as pets in aquariums. But seahorses from the wild often have a hard time living in home tanks. They need very special care and usually eat tiny live foods like brine shrimp. They can get stressed easily.

Luckily, it is now more common to raise seahorses in tanks. These tank-raised seahorses do much better because they are healthier. They can eat frozen foods like mysidacea that are easy to find in pet shops. They also do not have to go through the hard move from the ocean. Scientists found that feeding tiny plants called microalgae helps baby seahorses grow bigger and stronger.

When keeping seahorses in an aquarium, it is important to give them a calm space with gentle tank mates. They do well with shrimp and gobies, but should not be with faster or aggressive fish like eels, tangs, and triggerfish. Good water quality is important, with the right temperature, clean water, and enough space for them to swim.

Consumption

Seahorse populations are thought to be endangered because of overfishing and habitat destruction. Many people use seahorses in traditional Chinese medicine to help with health issues, but there is little proof this works.

The trade of seahorses is controlled under CITES, but some countries do not follow these rules. Dried seahorses can be very valuable in some places.

Species

Seahorses belong to the genus Hippocampus. There are 46 recognized species. These tiny fish look like horses with their horse-like heads and curly tails. They have bony armor and usually stay upright in the water.

Pygmy seahorses

Main article: Hippocampinae

Pygmy seahorses are very small members of the seahorse family. They measure less than 15 mm tall and 17 mm wide. These tiny creatures live close to other sea organisms like hydrozoans, coralline algae, and sea fans. Their small size and special features make them unique among seahorses.