Common Seahorse, Hippocampus taeniopterus Bleeker 1852

Known from the Darwin area to southern Queensland. Elsewhere, the species occurs in the tropical Indo-west Pacific, from Indonesia (Moluccan Seas, Sulawesi and Bali) and Papua New Guinea. The Common Seahorse inhabits shallow estuaries, harbours and bays, often sheltering along the edges of seagrass beds or amongst mangroves in depths to about 15 m. 

During the wet season, juveniles and adults may be carried well-offshore on floating weeds.

Dorsal fin 17-18; Pectoral fin 16-18 (rarely 17 or 18); trunk rings 11; tail rings 34-35; subdorsal rings 2 + 1-2.
Snout thick in adults, length about equal to post-orbital distance, much shorter than half head length;
Spines low and blunt in juveniles, reducing or becoming rounded and knob-like in adults; subdorsal spines 3-4/0,1,1-0,1,1,1; nasal spine small; shoulder-ring spines small, uppermost at gill-opening, central spine at level of lower pectoral-fin ray, lowermost single, not enlarged; large specimens often with many papillae on nape, interorbital and body.
Coronet small but well developed, appearing 'back-swept', with 5 divergent sharp spines on apex in young, spines becoming proportionally smaller with growth; in large adults, apex smooth with 3 rounded points angled posteriorly.
Lateral line pores small, somewhat distinct, becoming intermittent on tail, ranging to 20^th ring. Pores often positioned between 2 large papillae, although large specimens usually have many additional papillae on nape and interorbital, as well as body.

Height to 22 cm.

In life, overall grey to brown, often with fine dark spots, pale scribbles and striations; females sometimes yellow with pupil-sized black spots that may elongate on trunk over rings. In preservative - pale to dark brown, usually with small dark spots.

Carnivores. Like most other seahorses, this species presumably feeds by sucking small prey items such as crustaceans and planktonic zooplankton in through the long snout.

Sexes separate, males brood the developing embryos and give 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 provides physical protection for the developing embryos, he also osmoregulates and aerates the embryos and may provide some nourishment until the offspring are born.

There is no known trade in this species for the aquarium or Asian Traditional Medicine industries.

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/.
Marine Listed under the Federal Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act 1999). http://www.environment.gov.au/epbc/species/marine.html

H. taeniopterus is not as common in Australian waters as it is throughout other parts of its range. Adults regularly occur in floating weeds.

H. taeniopterus is most similar, and often confused with H. kuda, a species not found in Australian waters. H. kuda differs in having slight meristic and morphological differences, as well as usually having dermal appendages on the head spines, coronet, and on the enlarged spines or tubercles of superior ridges.

From the Greek ippos = horse and kampe = curvature. The specific name taeniopterus is from the Latin taenia meaning ribbon, fillet and pterus meaning wing.

Hippocampus taeniopterus Bleeker 1852, Nat. Tijdschr. Ned. Ind. 3: 306. Type locality: Ambon I., Molucca Is., Indonesia.

Dianne J. Bray & Vanessa J. Thompson