Coleman's Seahorse, Hippocampus colemani Kuiter 2003

Great Barrier Reef, Queensland, and Lord Howe Island in the Tasman Sea. Elsewhere the species may occur in Papua New Guinea, Taiwan, the northern Mariana Islands, Japan, and south to New Caledonia. At Lord Howe Island, the species was found in the lagoon on coarse sand amongst Zostera and Halophila seagrasses with fine filamentous algae on their leaves that matched the filaments on the seahorse.

Dorsal fin 12-13; Anal fin absent; Pectoral fin 10; trunk rings 12; tail rings 27-29; subdorsal rings about 4.
Body fleshy; head small, about half trunk length, strongly angled down onto trunk; snout short, about equal to eye diameter; a single relatively large gill opening present on neck ridge directly behind the head; nasal ridge well-developed in front of eye; cleithral ring continuous, strongly raised. Trunk very deep; trunk and tail ridges poorly developed; tail thin.

Spines reduced to low tubercles, snout spine present, large spine on the eighth lateral and fifth and 12th superior trunk ridges, wing-like-protrusions immediately posterior to head, largest tubercles below dorsal-fin base and on lateral part of head, some with dermal appendages. Nasal spine present as a well-developed ridge before the eye.

Coronet low, rounded with a tentacle-like dermal appendage anteriorly.
Dorsal-fin base greatly elevated posteriorly, forming a triangular hump on the back; anal fin absent.

Body mostly pale whitish to yellowish; trunk with white circular or elliptical markings, outlined with narrow red lines; shoulder-ring tubercles white; head white on nape above eyes, extending over snout to tip of mouth; several dusky brown bands radiating from eye; dermal appendages brownish-red; tail slightly more brownish with red markings.

Unknown; presumably feeds on minute invertebrates.

Sexes separate, with males brooding the eggs and giving birth to tiny independent young. The female uses an ovipositor to transfer her eggs into an elaborate enclosed pouch under the abdomen of the male. The male not only fertilizes the eggs inside the pouch and provides physical protection for the developing embryos, he also osmoregulates and aerates the embryos and may provide some nourishment until the offfspring are born.
An x-ray of one of the type specimens shows eggs filling the abdomen of the female.

Listed under Appendix II of the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES).

The species is named for Neville Coleman who discovered H. colemani at Lord Howe Island.

Hippocampus colemani Kuiter 2003, Records of the Australian Museum 55: 113, figs. 1-4. Type locality: Lord Howe Island.

Bray, D.J. & Thompson, V.J. 2025

Atlas of Living Australia