Marine life  /  Seahorses & pipefish  /  Pygmy pipehorse
Reviewed 2026-09-06
Species entry

Pygmy pipehorse

Acentronura tentaculata

Seahorse head, pipefish body, prehensile tail; grips algae and hydroids at 6 cm long.

Size
To 6 cm
Depth
3–25 m
Habitat
Algae, hydroids and rubble
Active
Daylight
Range
Indo-Pacific
Rarity
Lembeh Strait
4 stars of 5, two or three a season
SP-01
pygmy pipehorse · full body · habitat
4:3 · min 2400px

To about 6 cm, and intermediate in shape between the two families most divers know: the head is angled down from the body as a seahorse’s is, but the trunk is straighter and longer and the tail is prehensile and used to hold on. Brown to olive and mottled, with short fleshy appendages along the back and often enough algal growth on the body to blur the outline. It is taken for a juvenile seahorse, which has a more sharply angled head and a deeper, shorter trunk, and for the Lembeh pygmy pipedragon, Kyonemichthys rumengani, which is far thinner again, a thread rather than a body, and hangs vertically.

Algae, seagrass, hydroids and the tangle at the base of rubble slopes, between about 3 and 25 m, anchored by the tail and moving with the surge rather than against it. It is cryptic and largely stationary, and most records come from guides who know a patch of growth rather than from general searching, so the numbers say more about who was looking than about how common the animal is. Males brood in a pouch on the underside of the tail closed along the midline by two folds of skin, an arrangement between the open tail of the pipefishes and the sealed pouch of a seahorse.

Where to find:

LocationRarity Best monthsDepthHabitat
Lembeh Strait Indonesia editorial estimate
4 stars of 5, two or three a season
Year-round
3–25 m
Algae, hydroids and rubble
Anilao Philippines editorial estimate
4 stars of 5, two or three a season
Year-round
3–25 m
Algae and hydroids
Ambon Indonesia editorial estimate
4 stars of 5, two or three a season
Year-round
3–25 m
Algae, hydroids and rubble
Dauin & Dumaguete Philippines editorial estimate
4 stars of 5, two or three a season
Year-round
3–25 m
Algae, hydroids and seagrass
Bali Indonesia editorial estimate
5 stars of 5, a handful of records
Year-round
3–25 m
Algae and hydroids

Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.

Related species

SP
alligator pipefish
16:10
Alligator pipefish
Syngnathoides biaculeatus
SP
atlantic banded pipefish
16:10
Atlantic banded pipefish
Micrognathus crinitus
SP
banded pipefish
16:10
Banded pipefish
Dunckerocampus dactyliophorus
SP
barbour's seahorse
16:10
Barbour's seahorse
Hippocampus barbouri