Order : Syngnathiformes
Family : SYNGNATHIDAE
Species : As of 2024, 306 species in 59 genera
Maximum Length : up to 60 cm

The family Syngnathidae comprises pipefishes (more than 250 species of many genera), seahorses (nearly 50 species of the genus Hippocampus) and, limited to the coastline of Australia, the seadragons (3 species).

They possess long snouts and fused jaws. Their fins are greatly reduced in size (or some fins may be absent), but they can slowly propel the fish by rapid fanning of their small fins. Their body structure is formed by a series of bony rings, covered in bony plates.

Seahorses possess a prehensile caudal peduncle (i.e. a tail which can curl around and grasp onto fixed structures such as seaweed or branching corals).

Pipefishes and seahorses feed upon tiny, planktonic invertebrates which are rapidly sucked into their long snout.

Males assume the role of parent. The males of most species possess a brood pouch where the eggs of females are deposited; these are then fertilized, and incubated inside the male before the final hatchlings are expelled. In other species, males simply attach the fertilised eggs to their tail.

Numerous forms of pipefish and seahorse occur within the warm, shallow coastal waters of Southeast Asia, including brackish habitats.

Figs 1 to 3 : Male Seagrass Pipefish (Syngnathidae sp.) at low tide in warm, tropical, shallow waters in Singapore's northeast. The white, elongated, swollen structure at the abdomen appears to be the brood pouch (Figure 3).

Fig 4 : Intertidal habitat at low tide in Singapore's northeast.

Fig 5 : Spiny Seahorse (Hippocampus histrix) from East Timor.  Photo thanks to Nick Hobgood.

Links and references :

Fishbase - Syngnathidae

Wikipedia - Syngnathidae

Wild Singapore - Pipefishes

Wild Singapore - Seahorses