Sussex Seahorses

03 April 2020 | Posted in Ella Garrud , Marine
Sussex Seahorses
Short-snouted Seahorse © Paul Naylor

By Ella Garrud

Living Seas Officer

We have had a few reports recently of sightings of one our most elusive marine creatures – the small yet charismatic seahorse. We are lucky enough to have two species of seahorse in Sussex – the Short-snouted Seahorse (Hippocampus hippocampus) and the Long-snouted or Spiny Seahorse (Hippocampus guttulatus). The main distinguishing feature between the two species is the length of their snouts – hence their rather unimaginative common names. The Long-snouted Seahorse also has elongated spines down the back of its neck, giving it the look of a horse’s mane.

Spiny Seahorse in Seagrass©Alexander Mustard2020VISIONSussex Wildlife Trust

Spiny Seahorse in Seagrass by Alexander Mustard

But what are seahorses? They are in fact bony fish and in the family Syngnathidae, along with Pipefish and Sea Dragons. They don’t have scales, instead they have skin which is stretched over bony plates that give the impression of an exoskeleton. They are ambush predators, with a diet of small crustaceans such as shrimp. Interestingly, they don’t have teeth or a stomach – they catch their prey by sucking it in through their snouts where it is swallowed whole and passes through their digestive system very quickly. They therefore have to eat quite a lot in a day to simply stay alive – an adult seahorse will eat around 30 to 50 mysid shrimp a day, which is a lot considering their small size.

Both species can grow to about 15 cm in length and are found living in shallow waters, often in Seagrass beds. Here, they use their flexible tails to anchor themselves to blades of Seagrass where they wait for prey to swim across their path. They swim slowly using their dorsal fin on their backs for propulsion and the small pectoral fins below their gill openings to steer.

The main threat to seahorses in the UK is habitat loss. Without Seagrass and seaweed to hide in, they simply cannot survive. It is estimated that at least 49% of UK Seagrass beds have been lost over the past 35 years due to a variety of reasons. Globally, their main threat is from the Chinese medicine trade and by collection for the pet and souvenir trade. It is estimated that in excess of 150 million seahorses are taken for the medicine trade alone.

What should I do if I find a seahorse and how can I contribute to their conservation?

Both species of seahorses are protected in the UK and it is illegal to kill, disturb or take seahorses from British waters. Short-snouted Seahorses are also a protected feature of the Beachy Head West Marine Conservation Zone. Since 2010 it has been illegal to take flash photographs as it was found to be harmful to them. So if you are lucky enough to spot either of our fantastic seahorse species, make sure to give it space and simply observe it in its natural habitat, taking photos with the flash turned off. 

If you find a seahorse, you can contribute to scientific research. Download this form, fill it in and send it to The Seahorse Trust at [email protected] Every new form contributes to piecing together a better picture of these amazing animals in our waters and will help to protect them into the future.  


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