The ornate ghost pipefish (Solenostomus paradoxus) occasionally known as the harlequin ghost pipefish, is a pipefish of the family Solenostomidae frequently found along reef edges prone to strong currents.
The ornate ghost pipefish is one of the hardest fish to spot in the ocean.  First of all they are relatively small, only growing to about 12 centimetres in maximum length. This combined with the fact that their bodies look more like coral or seaweed than an actual saltwater fish, makes them a master of camouflage!

General Description
The ornate ghost pipefish can be recognised by its distinctive body form with slender appendages on the body and fins. It has deeply incised membranes in the dorsal, caudal and ventral fins.
Its colour varies from almost totally black to semi-transparent with red, yellow, and white scribbling, spots and blotches and they can reach a maximum length of 12 centimetres.
These pipefish are different to seahorses in several ways. The head is held at an angle to the body, but not at such a large angle as that of the seahorse. One also finds that they have two dorsal fins whereas a seahorse only has one. In addition, the ghost pipefishes do not have a pouch in which the young are reared, instead the female looks after the eggs in a pouch formed by her modified ventral fins. These fins are greatly expanded and united with the abdomen along the upper margin and together below for a brood pouch.
The ornate ghost pipe fish has the elongated snout and laterally compressed body that is typical of all syngnathoid fishes. More specific to the Solenostomid’s is a dermal skeleton composed of plates, a head region that represents over a third of the total body length and the presence of pelvic fins, 2 separate dorsal fins, an anal fin and a large ventral fin.
The females are larger than the males with an average length of 130 mm; males, on average, are 37% smaller.
These spend a lot of time floating upside down, mouth pointed downwards and virtually motionless.
During the breeding season, a murky, muddy bottom or a coral reef is the habitat of choice. Here they change not only their colour, but also their shape in order to camouflage themselves even better.

Eating:
These little treasures eat tiny crustaceans, sucked inside through their long snout.
They feed mostly on mysids but also target small benthic shrimps

Reproduction
This is an external skin-brooding species. Embryos are enclosed in an envelope and attached to special epidermal cells called cotylephores. These cells occur only on the inside surface of the pelvic fins of females (the brooders in this species). The pelvic fins of females are expanded and connect to the body and to each other in order to form a brood pouch (similar to that of a kangaroo).
Females carry eggs in this pouch during the incubation period. This method allows the female to move her young to a site that is better for survival and also limits the risk of exposure to predators during the brood’s developmental stage.
Life starts as a larvae adrift on the currents of the oceans. Maturity is gradually reached during this stage, before settling on the seabed.
At first, the fish will be transparent until it makes its way to the coral reef to reproduce. Here it will take on shape and colour to maximise its camouflage.
They will take a mate and pair off, a union that can often be observed for days on end. Once fertilized, the female will carry around up to 350 eggs in her brooding pouch. These eggs will eventually be set adrift, restarting the cycle of life once more.

Where to Find Ornate Ghost Pipefish
They usually solitary, but has also been observed in pairs or very small groups.
The species is found in protected coastal waters, at depths between 3 metres and 25 metres especially near coral and rocky dropoffs. Usually they will be found living within crinoids, feather stars, gorgonian fans and branching black coral bushes. Here they live very well camouflaged by their complex colour patterns and body shape.
Because they are relatively weak swimmers, rapidly fanning their little fins for propulsion, they tend to stay within very small territories. Even though the fins provide accurate navigation and precise positioning of their bodies, their range is extremely limited.

With a keen eye they are found on many dive sites of the Similan Islands. In Komodo they are also found by the passionate diver – but due to currents, they are not found on all sites.

Conservation
Coral bleaching, pollution and destructive fishing methods all impact on the habitat and the life cycle of the ornate ghost pipefish, the aquarium trade also negatively affect their numbers in the wild.

Colourful and distinctive, small and delicate, motionless and elongate, they are so small, (about the size of a finger) and blend in so well with their surroundings that they are near-impossible to find, divers who are willing to hover and stare at feather stars and gorgonians for long periods of time may just be rewarded for their patience!