Bargibant's Pygmy Seahorse

The pygmy seahorse measure less than one inch in length (2 cm), and is naturally well camouflaged and extremely difficult to see amongst the gorgonian coral it lives on. So effective is this camouflage that the species was not formally discovered by researchers until an apparent host coral was being examined in a laboratory; in 1969, a New Caledonian scientist named Georges Bargibant had been collecting specimens of Muricella gorgonians, for the Nouméa museum, when he happened to spot a pair of the tiny seahorses on the coral upon the examination table. The next year, they were officially named by Whitley as "Bargibant's pygmy seahorse". Large, bulbous tubercles (or knobs) cover its body, matching the colors and forms of the polyps of its host species of gorgonian coral, while its body matches the gorgonian stem (to which the seahorse wraps its tail around for stability).

The pygmy seahorse is found in coastal areas ranging from southern Japan and Indonesia to northern Australia and New Caledonia on reefs and slopes at a depth of 10–40 metres (33–131 ft).

Adults are usually found in pairs or clusters of pairs, with up to 28 pygmy seahorses recorded on a single gorgonian, and may be monogamous. As with other seahorses, the male carries the young. Breeding occurs year-round. The female lays her eggs in a brood pouch in his trunk region. They are fertilized by the male, and incubated until birth with gestation averaging two weeks. The brood pouches of male Bargibant's seahorses are unusually deep inside the body among seahorses. In one birth witnessed underwater, a male expelled a brood of 34 live young. The young or fry look like miniature adults, are independent from birth, and receive no further parental care. The fry are dark.

Very little is known about the total number of pygmy seahorses, population trends, distribution, or major threats. It has therefore been classified as Data Deficient on the International Union for Conservation of Nature's Red List. Because of the unusual and attractive colouration of this small seahorse, it is possible that it could be being collected for the aquaria trade, although no international trade in the species has been recorded. Under the care of experienced researchers at national aquaria, all pygmy seahorses and their gorgonians have died.