- Animals
- Photo Ark
- Common Name:
- Seahorse
- Scientific Name:
- Hippocampus
- Type:
- Fish
- Diet:
- Carnivore
- Group Name:
- Herd
- Average Life Span In The Wild:
- 1 to 5 years
- Size:
- 0.6 to 14 inches
What are seahorses?
The oddly shaped and upright-swimming seahorse seems an unlikely fish. Yet more than 45 species live in coastal waters around the globe. Scientists have learned their basic biology, but much remains unknown about these charismatic animals.
Physical description
Its head may resemble a horse’s, but each seahorse has a look all its own. Most are spotted, speckled, or striped, and some are decked out in skin frills, spikes, and crowns. Colors vary and can change with the twitch of a muscle to offer camouflage or to signal a foe or potential mate.
Seahorses have flesh-covered bony plates instead of scales, eyes that work independently of each other, and prehensile tails—used to grip holdfasts on the seafloor to avoid drifting and, during courtship, to link to each other.
The tiniest species is no bigger than a lima bean; the largest can reach more than a foot from head to tail tip.
Habitat and movement
Preferring calm, shallow waters, seahorses thrive in seagrass beds, mangroves, estuaries, and coral reefs in temperate and tropical waters around the world. Relatively inept swimmers, the fish get around with frantic beats (up to 70 times per second) of a dorsal (back) fin and rely on tiny pectoral fins for stability and steering. Easily exhausted, many are swept away in heavy currents or killed in storm-roiled seas.
Diet
Seahorses are ambush predators: They hold still and wait for krill, copepods, fish larvae, and other tiny edibles to float by and then nab them with remarkable speed. Toothless and lacking a stomach for food storage, the animals use their long snouts like vacuum cleaners to suck up plankton nearly continually.
This photo was submitted to Your Shot, our photo community on Instagram. Follow us on Instagram at @natgeoyourshot or visit us at natgeo.com/yourshot for the latest submissions and news about the community.
This photo was submitted to Your Shot, our photo community on Instagram. Follow us on Instagram at @natgeoyourshot or visit us at natgeo.com/yourshot for the latest submissions and news about the community.
Photograph by Danny Bergeron, National Geographic Your Shot
Courtship
Seahorses are dancers at heart, circling one another or a floating object, flashing colors, and intertwining tails during a sometimes days-long courtship. Said to mate for life, a pair’s commitment may actually be fragile: If the two are separated for a time, or if the male’s health declines, a female may switch partners rather than stick with her original choice.
Reproduction
In a reproductive role reversal unique to seahorses and others in the family Syngnathidae (which also includes pipefish and sea dragons), males experience pregnancy. During mating a female uses a tube called an “ovipositor” to place her eggs into the male’s frontal “brood pouch.” He then incubates, nourishes, and carries the young to term—usually two to four weeks. With powerful contractions he’ll give birth to fully developed fry, from dozens to more than a thousand depending on the species. Newborn seahorses, set adrift, are immediately vulnerable to predators, and few survive their early days.
Threats
Pollution and coastal development harm seahorses, but the top threat is rampant overfishing. Commercial fishermen scoop up millions of seahorses a year as bycatch. There is also targeted fishing of seahorses to supply tourist demand for dried trinkets and an unregulated traditional-medicine market in Asia.
Population data for many seahorse species is sparse, but scientists believe the vast majority are threatened and some populations in rapid decline. How warming seas due to climate change will affect seahorses long term is unknown.
Saving seahorses
Protecting seahorses will require protecting their shallow-water habitats from pollution and destructive development, enforcing commercial-fishing laws aimed at stemming the bycatch problem, and reducing demand for these animals as trinkets and supposed medicinal supplements.
DID YOU KNOW?
The genus name for seahorses, Hippocampus, roughly translates from the Greek to “horse-like sea monster” or, by another translation, “horse-like caterpillar.”
—UselessEtymology.com
The hippocampus in the human brain is named after the seahorse (genusHippocampus) as it resembles the fish in shape.
—UselessEtymology.com
A male seahorse may carry more than a thousand embryos in his brood pouch at one time.
—Zoe M. G. Skalkos, et al. Journal of Comparative Physiology B (2020)
While seahorses mostly stay put, some are known to migrate, often tucked into seaweed clumps that carry them long distances (called “rafting”).
—Project Seahorse
Seahorses are marine animals—living in saltwater—but can tolerate a range of salinity levels, including the brackish waters of estuaries, where fresh and saltwaters meet.
—Project Seahorse
While young are developing in the male seahorse’s pouch, he transports nourishment to them through a placenta—though exactly how it functions (there is no umbilical cord) is not yet known.
—Zoe M. G. Skalkos, et al. Journal of Comparative Physiology B (2020)
Insights, advice, suggestions, feedback and comments from experts
I am an expert and enthusiast-based assistant. I have access to a wide range of information and can provide assistance on various topics. I can help answer questions, provide information, and engage in discussions.
Regarding the information you provided about seahorses, I can confirm that seahorses are a type of fish belonging to the genus Hippocampus. They are known for their unique appearance and upright swimming posture. Seahorses have a head that resembles a horse's head, but each individual seahorse has its own distinct look. They come in various colors, patterns, and sizes, ranging from 0.6 to 14 inches in length. The smallest species is about the size of a lima bean, while the largest can reach over a foot in length.
Seahorses have flesh-covered bony plates instead of scales, and their eyes can move independently of each other. They also have prehensile tails, which they use to grip holdfasts on the seafloor to avoid drifting and during courtship to link to each other. Their tails are an important adaptation for their unique way of life.
Seahorses prefer calm, shallow waters and can be found in seagrass beds, mangroves, estuaries, and coral reefs in temperate and tropical waters around the world. They are relatively inept swimmers and rely on their dorsal fin for propulsion and their pectoral fins for stability and steering. However, they can easily become exhausted and are vulnerable to heavy currents and stormy seas.
In terms of diet, seahorses are carnivorous and primarily feed on small prey such as krill, copepods, fish larvae, and other tiny organisms. They are ambush predators and use their long snouts to suck up plankton with remarkable speed. Seahorses lack teeth and a stomach for food storage, so they continuously feed on small prey to meet their nutritional needs.
Seahorses have fascinating reproductive behavior. They are known for their courtship rituals, during which they circle each other or a floating object, flash colors, and intertwine their tails. It is believed that seahorses mate for life, although a female may switch partners if the male's health declines or if they are separated for a period of time. In a unique reproductive role reversal, male seahorses experience pregnancy. The female deposits her eggs into the male's brood pouch, where he incubates and nourishes them until they are ready to be born. The gestation period varies depending on the species and can range from two to four weeks. Male seahorses can give birth to dozens to over a thousand fully developed fry at once. However, the survival rate of newborn seahorses is low, as they are immediately vulnerable to predators.
Seahorses face various threats, including pollution, coastal development, and overfishing. Commercial fishermen often catch seahorses as bycatch, and there is also targeted fishing for seahorses to meet the demand for dried trinkets and traditional medicine in some Asian markets. Many seahorse populations are believed to be threatened, and the impact of climate change on seahorses is still uncertain.
To protect seahorses, it is important to preserve their shallow-water habitats, enforce fishing regulations to reduce bycatch, and reduce the demand for seahorses in the trade of trinkets and traditional medicine.
Did you know?
- The genus name for seahorses, Hippocampus, roughly translates from Greek to "horse-like sea monster" or "horse-like caterpillar".
- The hippocampus in the human brain is named after the seahorse (genus Hippocampus) because it resembles the fish in shape.
- Male seahorses can carry more than a thousand embryos in their brood pouch at one time.
- While seahorses mostly stay in one place, some are known to migrate by hitching a ride on seaweed clumps, a behavior known as "rafting".
- Seahorses are marine animals that can tolerate a range of salinity levels, including the brackish waters of estuaries.
- While developing in the male seahorse's pouch, the young receive nourishment through a placenta, although the exact functioning of the placenta is not yet fully understood.
I hope this information helps! If you have any more questions, feel free to ask.
