scientific name Acentronura tentaculata, is a small and fascinating fish species belonging to the Syngnathidae family. This family includes seahorses, pipefish, and pipehorses, and they all share a characteristic elongated body shape and lack of pelvic fins. The Hairy Pygmy Pipehorse can grow up to 6 cm in length and has a slender, elongated body with a small head and a long snout. Their overall shape and features are very similar to those of a seahorse, with a prehensile tail used to cling onto seagrasses or coral reefs.

The body coloration and pattern of Hairy Pygmy Pipehorses are highly variable, and they can change their appearance to match their surroundings for camouflage. They typically have brown or greenish hues with irregular markings or stripes, which help them blend in with the seagrass or coral they inhabit. One of the most distinctive features of this species is their "hairy" appearance, with small fleshy appendages growing from their body that resemble algae or other types of vegetation. This allows them to better blend in with their surroundings and avoid predators.

Hairy Pygmy Pipehorses are generally solitary and have little social behavior. They are not very active swimmers and prefer to remain stationary in the water column, using their long snouts to feed on small crustaceans and other zooplankton. Like other Syngnathids, they have a highly specialized feeding mechanism, with a small mouth adapted to sucking in prey items. They use their long snout as a pipette to suck up prey and consume them whole.

In terms of fashion, Hairy Pygmy Pipehorses are highly sought after by the aquarium trade due to their unique appearance and behaviors. However, they are not easy to maintain in captivity and require specific water parameters and a varied diet to thrive. They are also listed as a species of "Least Concern" by the International Union for Conservation of Nature (IUCN), but their populations may be at risk due to habitat loss and degradation caused by human activities such as coastal development and pollution.