Queensland Seahorse, Hippocampus spinosissimus Weber 1913

Endemic to tropical waters of north-eastern Australia, from Princess Charlotte Bay to Southport, Queensland; benthic in inner reef waters on rubble substrates and in sponge and seagrass habitats near coral reefs at 20-63 m; often attached to corals in deep current-prone channels between reefs or islands.

Meristic features: Dorsal fin 16-18 (rarely 16 or 18); Anal fin 4; Pectoral fin 16-19 (rarely 16 or 19); trunk rings 10-11 (rarely 10); tail rings 35-36; subdorsal rings 2 + 1.
Head prominent, relatively mobile, held at right-angles to the trunk axis; snout long, slightly more than half head length; inferior tail ridge with moderate spines along pouch section of males, filaments absent; nasal spine absent;
Spines and tubercles: Trunk ridges with broad-based small spines on nearly all intersections, some enlarged. Juveniles more spiny, with enlarged spines on rings 1, 4, 7 and below dorsal fin. Subdorsal spines 3/0,1,0. Spine above eye equal to pupil length, directed dorso-posteriorly; nasal spine absent, nasal profile straight; shoulder ring spines long, uppermost at gill opening, central spine at about level of 13^th pectoral-fin ray, lowermost a blunt, rounded spine, with a second, less-developed, forward-directed spine; lateral head spine moderately long; superior tail ridge spines moderately long, enlarged on 4^th, 7^th and 10^th ring; inferior tail ridge spines of moderate length along pouch section of males.
Coronet: Coronet moderately low, with 5 spines. coronet small with 5 diverging spines at apex, posterior-most longest.
Lateral line: Lateral line distinct with small pores, most associated with double papillae on tail, ranging to 16^th tail ring.

Colour variable in life, snout yellow-orange to deep red or dark brown, front of head usually darker or dusky; pale grey saddles or bands with dark margins over trunk and tail, one broadly over first 3 trunk rings, a narrower saddle on 7^th ring usually reaching ventral ridge, and one or two broad and narrow saddles anteriorly on tail. Deep water specimens usually red or orange, possibly matching colours of corals and sponges at that depth. In preservative - pale to blackish-brown with dusky or grey saddle-like markings.

Carnivores. Like most other seahorses, this species presumably preys on small crustaceans and other planktonic invertebrates.

Males brood and nourish the developing embryos before 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.
Juvenile average height, 5.63 mm.

None. Although taken in trawls, there is no known trade in this species for the aquarium or Asian Traditional Medicine industries.

International: Listed under Appendix II of the Convention on the International Trade in Endangered Species of Wild Flora and Fauna (CITES). As a result, the species is subject to the Convention, http://www.cites.org/.
Australian legislation: Marine Listed under the Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999). http://www.environment.gov.au/epbc/species/marine.html

Most similar to H. alatus, differs in usually having more elongate and sharper spines. Differs from H. semispinosus in its colour pattern and in having a shorter, less slender snout.

Hippocampus spinosissimus Weber, 1913, Fische Siboga: 120. Type locality: Sapeh Strait, Indonesia, Siboga station 49, 70m.

Dianne J. Bray & Vanessa J. Thompson