Pygmy seahorse

Lore & Background

The first pygmy seahorse discovered was Hippocampus bargibanti. In 1969, a New Caledonian scientist, Georges Bargibant, was collecting specimens of Muricella spp gorgonians for the Nouméa museum and whilst one of these was on his dissection table he happened to notice a pair of tiny seahorses. The next year they were officially named by Whitley as Bargibant's pygmy seahorse. At least six more species were named after 2000. Other species live on soft corals or are free-ranging among seagrasses and algae. Pygmy seahorses are both tiny and well camouflaged. They are very difficult to spot amongst the sea grasses, soft corals, or gorgonians that they inhabit. Other distinctive characteristics include a fleshy head and body, a very short snout, and a long, prehensile tail. With their short snouts, they have the appearance of baby animals. True pygmy seahorses have a single gill opening on the back of the head, instead of two on the sides, and males brood their eggs within the abdomen rather than in a pouch on the tail.

Reader's Guide

The pygmy seahorse is significant for its extreme camouflage and specialization. The first species discovered, Hippocampus bargibanti, lives exclusively on fan corals and matches their colour and appearance so effectively that it was discovered only when a host gorgonian was being examined in a laboratory. This discovery highlights the difficulty of observing such cryptic species in the wild. Subsequent species, such as Denise's pygmy seahorse (Hippocampus denise), also live on gorgonian corals but have been found on eight different genera, each individual staying on the same coral for its entire adult life. Other species, like Pontoh's pygmy seahorse (Hippocampus pontohi) and Satomi's pygmy seahorse (Hippocampus satomiae), are free-living and found on seagrasses, algae, or hydroids. The pygmy seahorse's legacy includes the discovery of multiple species after 2000, expanding knowledge of biodiversity in the Coral Triangle. The smallest species, Satomi's pygmy seahorse, is the world's smallest seahorse at up to 1.4 cm. The group also includes species with very restricted ranges, such as the Walea soft coral pygmy seahorse (Hippocampus waleananus), which lives only in the Tomini Gulf of central Sulawesi, Indonesia, and depends on the continued existence of soft corals there.

Did You Know?

• The first pygmy seahorse was discovered in 1969 when a scientist noticed a pair on a gorgonian coral on his dissection table.
• Satomi's pygmy seahorse (Hippocampus satomiae) is the world's smallest seahorse, reaching up to only 1.4 cm (0.55 in).
• Denise's pygmy seahorse was brought to scientists' attention by underwater photographer Denise Tackett.