Syngnathoides

Lore & Background

The alligator pipefish (Syngnathoides biaculeatus) is the only species in the genus Syngnathoides. It inhabits shallow waters of the tropical and subtropical Indo-Pacific, from East Africa to northern Australia, living in seagrass and seaweed habitats. It hides by positioning itself vertically with its head down among similarly colored fronds. The elongated, well-camouflaged body can reach 29 cm in length. The narrow head has a snout tipped by a pair of short tentacles, and the body is tetrahedral. The tail is long, tapering, and prehensile, lacking a tail fin, and is used to anchor the fish to vegetation. Color matches the surroundings, usually green, brown, or grey; females are often blotched and may have a white zigzag line along the abdomen.

Reader's Guide

The alligator pipefish is an inefficient swimmer, moving by undulating its pectoral and dorsal fins. It feeds by sucking up prey, including zooplankton, amphipods, mysids, shrimps, other benthic invertebrates, and small fish. The species is sexually dimorphic, with males larger than females. Males mature at about 180 mm. Breeding occurs during summer in Moreton Bay, Queensland, but at any time of year in Papua New Guinea. Females produce 60 to 200 eggs, which are retained by the male in a brood pouch on his abdomen until hatching. The male and female appear to have a monogamous relationship, with all developing eggs at the same stage, presumably from a single female. The fish is dried and used in traditional Chinese medicine as 'hailong' and appears in the pet trade. The IUCN lists it as 'data deficient' due to insufficient information on population trends and the source of traded fish. It is a listed marine species under the Australian Environment Protection and Biodiversity Conservation Act 1999.

Did You Know?

• The alligator pipefish is the only species in the monotypic genus Syngnathoides.
• Males are larger than females and carry the eggs in a brood pouch on their abdomen.
• The IUCN considers the species 'data deficient' due to lack of population and trade data.