September’s Object of the Month is a Spiny Seahorse found on the east coast of England at Skegness, Lincolnshire in 1904. The dried specimen was donated to the Museum by a resident of Saffron Walden. It is 12 cm long from head to tail.
There are two species of British seahorse. The Spiny Seahorse, Hippocampus guttulatus, and the Short Snouted Seahorse, Hippocampus hippocampus. The main difference between the two species is the length of the snout. The Spiny Seahorse has a longer snout and spines on the back and the head. They can grow to 18cm in length and live for 10 years.
Seahorses live in shallow coastal waters around the British Isles, up to the Shetland lsles, and Ireland. A Short Snouted Seahorse was seen for the first time at Harwich Harbour, Essex in 2023. They are poor swimmers and rely on their prehensile tail to cling onto seaweed and seagrass to stop themselves being swept away. A small dorsal fin beats 35 to 70 times per second to provide weak forward propulsion. Seahorses feed on small shrimp, crab and plankton. Their eyesight is good and the flexible snout can get into crevices in rocks. Prey is sucked up through the snout because seahorses do not have teeth. In winter they migrate to deeper water and anchor themselves to rocks or seaweed to ride out storms.
Fish: Seahorses are fish! They are related to pipefish and sea dragons.
Pregnancy: the males get pregnant.
Seahorses are the only animal with a true reversed pregnancy. The female transfers the eggs to the male with her ovipositor. He fertilises them and keeps them in his brood pouch to grow. Then he gives birth to live young called fry. Seahorses are monogamous and have one partner for the breeding season from April to October. It is not thought that they mate for life now.
Colour: seahorses can change colour like chameleons.
This helps camouflage them to hide from predators and in courtship. Each day the female meets the male in his territory, they change colour and perform a dance where they may circle each other, or an object, and hold tails.
Seahorses are endangered. They are legally protected by CITES (Convention on the International Trade in Endangered Species) and The Wildlife and Countryside Act. It is illegal to import, kill, capture or disturb a seahorse.
Seagrass meadows can be destroyed by anchors, fishing nets, dredging, drilling for oil and pollution. 92% of meadows have been destroyed. Marine Protect Areas are being set up around Britain to protect biodiversity.
Seahorses are captured for the pet trade or killed and dried for use in traditional medicines or sold as souvenirs.
A marine heatwave around Britain in April 2023 saw seas reach their highest recorded surface temperature of 210C. Seagrass meadows are stressed by heat. Ocean heatwaves cause mass mortality of marine plants and animals and the collapse of food chains. Sea ice also is melting and ocean circulation has slowed down due to higher global temperatures.
If ocean currents change direction or stop the supply of plankton that seahorses depend on for food may be disrupted.
How can you help?
Never buy souvenirs of dried sea creatures such as seahorses, starfish or shells which are homes for hermit crabs.
Reduce your use of plastics and buy fish that is caught sustainably.
Use eco moorings when sailing to anchor your boat.
Support a marine conservation charity such as The Seahorse Trust www.theseahorsetrust.org Donate or volunteer and you can even adopt a seahorse!
Report sightings of seahorses to The Seahorse Trust via the British Seahorse Survey website
Image (above): Spiny Seahorse, Hippocampus guttulatus SAFWM : 1975.68 ©