Staci-lee Sherwood
- Aug 19, 2022
- 5 min read

Dragons of the sea

Updated: Mar 29, 2023

By Staci-lee Sherwood

The most fascinating and unique characteristic of the Syngnathidae family is how it’s the male that gives birth. This fish family includes Seahorses, Pipefish and Seadragon. Having a head like a horse, Seahorses and Seadragons stand out as a fish species in the marine world. They are true rock stars of the ocean and a favorite among photographers. Their tiny size and elusiveness just add to their appeal.

Seadragons

Lesser known than their more famous cousins they are stars in their own right. These tiny dragons of the sea are larger in size with more color and intriguing patterns. Found only in southern Australian waters makes them rare. There are three recognized species, the Weedy, Leafy and newly described Ruby seadragon.

Elusive species are more alluring to scientists because of the chance to be the first to discover something new. Not much is known about their lives and researchers hope to shed light on these rainbow colored fish. Their diet consists of tiny mysid shrimp and other zooplankton. After mating the female deposits up to 300 eggs into the male’s brood patch who then fertilizes and carries them till birth. Despite their being much larger than Seahorses, which range in size from 1 - 6 inches, they produce about 1/3 of the eggs. Seadragons range in size from 13 - 18 inches

In 2006 the IUCN listed them as Near Threatened on the Red List. A lot has changed since then. As the Seahorse population continues to decline China might look more toward the Seadragon to fill the void.

A stunning Weedy Seadragon

Seahorses

One fascinating fact about this family of fish they lack teeth or stomachs. Instead they suck up food through their snout. Lacking a stomach means food goes in and out rather quickly. Seahorses will mate for life. During the courtship dance they curl their tails and change color. Following the mating ritual it’s the female that deposits up to 1,000 eggs in the male’s pouch. A handy survival skill, like the chameleon, they can change color to blend into their surroundings.

Diminutive in size they capture the imagination of young and old alike but are in serious danger of going extinct. Illegal harvesting by China for traditional medicine, used as decoration in key chains and pendants and polluted water have taken their toll. Without global bans on their exploitation and fierce enforcement the world could lose these horse looking fish. There are over 40 recognized species globally.

Florida

Many Floridians don’t know we have three species of seahorses, the Dwarf, Lined and Long Snouted. These are all listed as either Vulnerable or Threatened in US waters. One of the biggest threats in Florida is the heavily polluted water they live in. Seahorses live in shallow tropical waters where their habitat is coral reefs, seagrass beds and mangroves. Unfortunately in Florida the water quality is so poor most of the seagrass is dead while the bleaching of coral reefs has caused their decline. A bleak future awaits this species.

Globally all species are being pulled from the ocean so Florida populations are at risk of extinction. A favorite among divers, some local populations have fan clubs where divers will make special trips hoping to see them.

Seahorses mating in the water column at Blue Heron Bridge in Florida, USA 2022.

A rare photograph of a male Seahorse giving birth, at Blue Heron Bridge in Florida, USA 2022

A Lined Seahorse

Australia

The White’s Seahorse, also known as the Sydney Seahorse, has a population decline over 90%. In 2018 they became the second seahorse species in the world to be listed on the IUCN Red List Status as endangered. Alarmed scientists took this opportunity to try to save them in a unique way. Research showed this species uses artificial reefs if natural ones are absent. David Harasti, Senior Research Scientist at Port Stephens Fisheries Institute, created the ‘Seahorse Hotels’ out of metal cages. Once placed underwater they soon attract a variety of marine life like Coral and Sponges. In a matter of weeks they’re covered and start attracting endangered Seahorses.

I spoke with Dr. Harasti about the use of these hotels for other species, especially those found in other parts of the world. Regarding their use Harasti said “the use of hotels may only be suitable for particular seahorse species. We know that they work really well for those species that like artificial habitats such as the White’s seahorse and Pot-belly seahorse in Australia and the Short-head seahorse found in Europe.”

Captive bred juvenile seahorses are released into hotels hoping they will breed and help recover their population. Surveys show adult seahorses have also taken to them. The project has only been around a few years so it’s too early to tell if the population will rebound. Illegal harvesting worldwide must stop and laws must be enforced. With such a steep decline of a species that gets little attention we need real conservation on a global scale now. Click here to learn more about these hotels and watch some amazing videos https://www.dpi.nsw.gov.au/fishing/species-protection/what-current/endangered-species2/whites-seahorse

Standard open style hotel after a few days underwater

The same hotel after 14 months. Over time they provide food and shelter

Two tagged juvenile White's Seahorses living in a hotel 4 months after deployment (Photo: D. Harasti)

South Africa

In 2017 a photograph taken off the eastern coast of South Africa in Sodwana Bay by Savannah Nalu Olivier showed a new species barely the size of a fingernail. After viewing the photograph, pygmy seahorse expert Richard Smith realized this was a new discovery. This is the first pygmy seahorse discovered in the Indian Ocean. Most pygmy seahorses survive by camouflage among vegetation so what an amazing find to see something so microscopic. To read the 2020 study click here https://zookeys.pensoft.net/article/50924/

An adult male Hippocampus nalu will grow to a maximum of just ¾ of one inch long. Photo by Richard Smith, via University of Leeds

Global threats

According to Seahorse Trust the biggest threat to survival is the taking of an estimated 150,000,000 every year, mostly by China, to be used in their traditional medicine. The use of Seahorses for asthma and impotence has no scientific basis and can be fixed with modern medicine. Another 1,000,000 are caught for captivity in personal aquariums. There are no accurate numbers for how many end up used in trinkets but it’s estimated 1,000,000 are lost. At this rate we will push this species toward extinction.

In the past twenty years there has been a global increase in the capture and selling for use in about 80 countries. Varying degrees of threats exist for different species and different regions. Somewhere between 50 -97% decline in their population makes for an urgent call to end their use whether for personal and medical reasons. The world must agree to a ban with enforcement or lose one of its most amazing creatures .

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