With their horse-like heads, long tails and protruding bellies, these beautiful creatures are certainly like something out of a fairytale. The enlarged belly of the males is one of thier most distinctive features, which they wear puffed-out like a badge of honour – the bigger the pouch, the more attractive he is to a prospective mate.
Sea horses are members of the vibrant and colourful syngnathidae family, which also includes sea dragons and pipefish. Although Big-bellied Seahorses are a little more conservative with their fashions, with their colour ranging from a pale cream to dark yellow with brown spots.
What is special about them?
The Big-bellied sea horses’ long tail contributes to their claim as one of the world’s largest seahorse species. Reaching up to lengths of 30 centimetres, the Big-bellied Seahorse has a long, curly, grasping tail. They use this curly appendage to attach themselves on to branches of seaweed and sea grass, anchoring themselves against the swirling current.
Among the slowest swimming animals in the world, the Big-bellied Seahorse has tiny, translucent fins along their back and on each side of their neck. These are used for balance, with the dorsal fin on their back used for propelling them through the water. As they are so slow-moving, their common shades of yellowy-brown are perfect in helping them hide among the sea grasses and seaweed – making them almost invisible to predators.
What is their breeding behaviour?
The dance of the seahorse is one of the most beautiful courting behaviours in the ocean. At dawn and dusk, male and female sea horses entwine their tales, breaking off occasionally to “dance” by circling each other for up to several minutes at a time. For some couples, these dances can continue for a few hours, until the male finally wins over his mate by inflating his pouch.
Marine animals have some seriously bizarre breeding behaviours, with seahorses perfectly illustrating this mixed-up underwater world. Female seahorses produce eggs and give them to the male, where he fertilises them in his pouch and carries them for about 30 days, with the number of births depending on the size of his pouch. Arriving as adorable miniture versions of their parents, the young seahorses are born at night to protect them from predators and other hungry seahorses in the colony.
Where do they live?
The Big-bellied Seahorse is the most common seahorse in southern Australian waters. They are found in shallow waters of up to five meters, from eastern Victoria to South Australia, including Tasmania.
Seahorse nurseries are found among seagrasses, while adults prefer areas with more seaweed. Artificial structures, such as jetties, nets and salmon cages also are also favourite haunts.
Although slow swimmers, the Big-bellied Seahorse is unlike other seahorse species as they are quite a strong swimmer. They have been known to swim over hundreds of meters in the course of a day, no doubt finding the perfect home for their colony.
What do they eat?
Seahorses forage on tiny shrimps and other crustaceans found within their habitat. They wait until prey comes close enough and then suck it quickly out of the water with their long snouts. They will ingest almost anything small enough to fit into their mouths.
Big-bellied Seahorse Fast Facts:
- Common Name: Big-bellied Seahorse
- Scientific Name: Hippocampus abdominalis
- Habitat: Shallow areas of sea grass
- Diet: Mysid shrimp and plankton
- Size: Up to 18cm
- Range: Central to southern coasts of New South Wales
- Threats: Habitat loss
- Conservation Status: Not assessed