The life cycle of a seahorse

COURTSHIP: Seahorses court for several days at a time. The courting ritual involves dancing, changing colour and entwining tails. Sometimes, more than one male seahorse will compete to win the affections of a female, or vice versa. Males can inflate their pouch by pumping water through it to display its emptiness. This is to entice the female to deposit her eggs in it.

Typical seahorse courting rituals involve dance routines which last hours. Image via weheartit.com

EGG TRANSFER: The female deposits her egg in the water in order to transfer to the males pouch. The male releases his sperm directly into seawater to fertilize the eggs. They are then embedded in the pouch wall and become surrounded by a spongy tissue. The number of eggs varies between species.

PREGNANCY: Although the male carries the baby, the initial conditions in the pouch are determined by the nutrients provided by the female, but when the eggs are in the pouch conditions are controlled by the male. He provides oxygen and nutrients through a network of capillaries. The embryos will remain in the pouch for two to six weeks, depending on species and temperature, as they develop into fully formed juveniles.

It is the male seahorse that becomes pregnant. Image via weheartit.com

BIRTH: When the male seahorse is ready to give birth he has muscular contractions to expel the young, which are known as fry, from the pouch.

YOUNG: Newborns measure between two and twelve millimetres, depending on species. The number of young produced ranges between 100 and 200 for most species, but can be as low as 5 for the smaller species, or more than 1,500 for larger species. The fry will often grasp floating or still objects, and even each other, with their tails. 

Baby seahorse, known as fry, are born fully functioning. Image via weheartit.com

JUVENILES: Newly released young undergo only small changes after emerging from the father. During growth some body proportions may change but they don’t experience major body changes. Some newborns emerge with a small fin which is lost over time.

ADULT: Mature male seahorses have the ability to become pregnant any time during the breeding season, which varies with species. This is thought to be influenced by environmental conditions such as water temperature.

Pygmy Seahorse (Hippocampus Bargibanti)

All images via Wikimedia Commons

Seahorse found washed-up at Dorset nature reserve

An unusual discovery has been made at Purbeck’s Arne Nature Reserve. What was originally thought to be a small toy was found to be the remains of a real seahorse. Short-snouted and Spiny seahorse  are known to be inhabitants of Poole Harbour and the surrounding areas, but it isn’t often they appear on the shores of Shipstall Beach. A short-snouted seahorse, the less common of the two species relative to the British Isles, was spotted by a walker before being passed onto RSPB volunteer and wildlife enthusiast, Graham Tarrant.

The short-snouted seahorse had only minor damage to it's snout and it's skin had started to degrade. Image via Graham Tarrant

His son and fiancé, both marine biologists, were visiting for Christmas and suggested doing something with the seahorse rather than bury it. The inital plan to contact the Dorset Wildlife Trust, for which Graham is a member of, failed as they had closed for Christmas. It was then that Neil Garrick-Maidment of The Seahorse Trust was contacted.

“Polly, my future daughter-in-law emailed Neil to find out what we could do with it. There was a great debate whether to freeze it or pickle it”, Graham said. “I still remember from my A Level in Zoology that we put everything in Formalin to preserve it. Surgical spirit was the purest alcohol we could think of that we could easily get hold of, apart from vodka but that seemed a waste.”

Less than 1% of young seahorses make it to adulthood. Image via Graham Tarrant

Before it was stored in the alcohol, Graham took photographs of the creature to send to The Seahorse Trust, in advance. The images show it was a small, male seahorse just under 8cm. Although it was not pregnant at the time it is thought that it may have previously been.

Graham travelled, just after New Year, from Wareham to Ottery St Mary, where The Seahorse Trust is based. Putting it in the spirit, as opposed to freezing it, meant it is possible to still retrieve its DNA. Research can be carried out and DNA testing on enough samples could indicate some idea of population size for a certain area.

Although a rare occasion, this isn’t the first seahorse to be washed up in Dorset. In 2010 a number of spiny seahorse appeared on the shores of Hamworthy.

If you spot a seahorse washed ashore on any beach in the UK contact The Seahorse Trust on 01404 822373 or email them at info@theseahorsetrust.org

Seahorse FAQ

There’s no denying that seahorses are fascinating, magical little creatures but, apart from being pretty, what do we actually know about them and why are they so important? This page will answer the common (and the not so common) questions swimming through your brain, to give you a better insight into the life of a seahorse.

Where does the seahorse get its name?

  • Seahorse derives from the Ancient Greek word ‘hippocampus‘. ‘Hippos’ meaning ‘horse’ and ‘kampos’ meaning ‘sea monster’.

How many different types of seahorse species are there?

Which type of seahorses live around the British Isles?
Where are they found around the English coast?
  • The Short-Snouted Seahorse is found along the south coast of England and the Channel Islands. The Spiny Seahorse is also found along the south coast but also along the west coast up to the Shetland Isles.

Can seahorses make a noise?

  • Seahorses produce clicking and popping sounds during feeding and courtship. They do this by moving two parts of their skull against each other.

What is the name for a group of seahorse?

  • A Herd

A group of seahorses is known as a Herd. Image via weheartit.com

What is the average life span of a seahorse?

  • There is no definite answer but it ranges from roughly one year for the smaller species to an average of three to five years for the larger species.

What do seahorses eat?

  • Brine shrimp, tiny fish and plankton. An adult eats 30-50 itmes a day. Seahorse fry (baby seahorses) eat a staggering 3000 pieces of food per day.

How do seahorses eat?

  • Seahorses have no teeth and no stomach. Food passes through their digestive systems so quickly, they must eat almost constantly to stay alive.

How do seahorses have babies?

  • The female seahorse lays the eggs and transfers them into the male seahorses pouch where they are then incubated. Every male seahorse has an incubation pouch in its body.  The eggs are fertilized by the male, who also goes through the labour process and it takes 2-3 weeks for the babies to be born.

It is the male seahorse who gets pregnant and gives birth. Image via weheartit.com

What are the main threats to seahorses?

There are three main reasons seahorses are at risk:

  1. Firstly, the Traditional Chinese Medicine Trade take in excess of 20 million seahorses a year from the wild to be used for medicinal purposes.
  2. They are used as souvenirs in many countries. They are deliberately taken from the sea by the Curio Trade and left to die in the boiling sun.
  3. The pet trade takes an estimated one million seahorses. It is thought that less than 1,000 of these live for more than six weeks.

Pygmy seahorse Code of Conduct

Marine life expert and underwater photographer, Dr Richard Smith, has dedicated much of his time to allowing us less ocean-knowledgeable folk an in-depth look at a habitat we wouldn’t usually have the privilege to see.

Pygmy Seahorse Bargibanti captured by Dr Richard Smith via OceanRealmlmages.com

Educated from one end of the globe to the other, he has a Zoology degree from Southampton University, England and an MSc in Ecology and Evolution from the University of Queensland, Australia. With over 2000 dives under his belt Richard has achieved Divemaster status. It was just last year that Richard was awarded a doctorate for his research into the biology and conservation of, yes you guessed it, seahorses. Pygmy to be specific. It was during his PhD in which he created the Code of Conduct for diving with and photographing pygmy seahorses.

“I’m trying to have the Code of Conduct reach as many divers as possible and it’s always great for the general public to learn more about seahorses too.” – Dr Richard Smith

Pygmy seahorses have the smallest population of any species of seahorse. Measuring between 1.4 and 2.7 cm in length, their size makes them extremely fragile and delicate, and caution must be taken when documenting them and their habitat. Dr Richard Smith’s main aim is to reduce the negative impact that divers have on these rare animals and, to ensure greater protection of this species, created The Code of Conduct guidelines presented here:

  1. Do not touch or manipulate pygmy seahorses in any way, as this can easily damage or even kill them
  2. Do not touch the gorgonian home of the seahorse (they are extremely slow-growing and delicate), take particular care of camera position and exhalent bubbles
  3. Do not use a torch/flashlight or camera focus light to highlight a pygmy seahorse, this disorientates and stresses them
  4. Use white balanced natural light rather than artificial light for video capture to reduce disturbance from bright lights
  5. Five photo limit per diver using flash photography, as more can stress the animal
  6. No night diving with pygmy seahorses – they sleep at night and lights disturb them
  7. Be aware of the surrounding environment, pay close attention to fin positioning, so not to damage other corals

Pygmy Seahorse Denise captured by Dr Richard Smith via OceanRealmlmages.com

Find out more about the work of Dr Richard Smith visit his website, Ocean Realm Images and keep up to date with him on Twitter @Rich_Underwater 

Government delay plans to introduce MCZs

The government have withdrawn their decision to confirm the introduction of Marine Conservation Zones, around the coastline of the UK, early next year. Plans to protect certain areas of the ocean, in order to give marine life a safer environment to live, were set to be designated at the beginning of 2012. These plans have now been postponed until at least 2013.

Insufficient evidence was provided by stakeholder groups according to Defra, the government department for environment, food and rural affairs. Defra Environment Minister Richard Benyon said, “it is vital that we have an adequate evidence base for every site if we are to create successful well-managed MCZ’s.” He continued, “the need to strengthen the evidence base for the MCZ recommendations means this is going to take longer than the ambitious target first put forward.”

Map showing Marine Conservation Zones originally planned for 2012. Image via Julie Hatcher

One of the proposed sites around the coast of the UK is Studland Bay, Dorset. Julie Hatcher, Marine Conservation Officer for the Dorset Wildlife Trust explained, “originally the government said [the lack of evidence] shouldn’t delay the process because we need to have these areas in place as soon as possible. They said the best available evidence was good enough. Now for some reason they’ve gone against that.” Below she explains more:

Studland is thriving with marine life and is home to the two species of seahorse, Spiny and Short-Snouted. Since 2008 these seahorse have been legally protected by the government under the Wildlife and Countryside Act when there were added to a list of species protected by law. The seahorse is one of the very few marine species on this list after much concern that they needed protection. Julie explained, “the statutory authorities are already looking at putting management in place to make sure seahorses and their habitat aren’t being damaged. That’s going ahead anyway, whether or not the MCZ goes forward.”

Spiny seahorse which gained legal protection in 2008. Image via Dorset Wildlife Trust

Although the seahorses of Studland have protection, the rest of the marine life in the area, including the endangered Undulate ray, and around the UK do not. Studland Bay has sufficient evidence to support how sensitive the area is for wildlife but many areas’ data collection is not as solid. This has delayed Defra’s plan to confirm designation of sites, however there has not yet been a definitive answer as to how much data is sufficient.

Julie Hatcher explains below why Marine Conservation Zones, in her opinion, are so important.

Poll: How much do you know about seahorses?

It worried me when I found out that, to some people seahorses were simply characters of myth and not actual living creatures. Seahorses play as much of a vital role in the make-up of marine ecosystems as every other sea creature.

This poll was created to find out how many people are aware of the role of a seahorse within the marine environment, and for those that aren’t, whether they have an interest in finding out more.