Forest Halfbeak (Hemirhamphodon pogonognathus)

Forest Halfbeak (Hemirhamphodon pogonognathus)

A pair of Forest Halfbeaks resting at the side of a fast-flowing stream.

Family: Zenarchopteridae

Species Name: Hemirhamphodon pogonognathus
Common Name: Forest Halfbeak, Malayan Forest Halfbeak
Presence in Singapore: Native
Habitat: Freshwater forest streams
Conservation Status: Endangered (Red Data Book 3)

The Forest Halfbeak is the rarer of the two halfbeaks found can be found locally in freshwater. It is widespread across the Central Catchment Nature Reserve with its stronghold being the Nee Soon Swamp Forest. They seem to prefer acidic freshwater streams to the extent of living in blackwater. At first glance, the Forest Halfbeak can look similar to the Pygmy Halfbeak (Dermogenys collettei) but can be told apart from several features:

1. The dorsal fin of the Forest Halfbeak starts beyond the the anal fin while it is the opposite for the Pygmy Halfbeak.

2. The Forest Halfbeak is a much more colorful fish and is larger, reaching a maximum size of 9 to 12cm.

3. The end of the Forest Halfbeak's lower jaw curves down a little.

Like all halfbeaks, the Forest Halfbeak is a surface dweller that feeds opportunistically on prey such as fallen insects. Being in the family Zenarchopteridae (Viviparous Halfbeaks) alongside the Pygmy Halfbeak, the Forest Halfbeak practices internal fertilization and give birth to live young. 

A lone Forest Halfbeak displaying its beautiful colours.

References

• Lim, K.P. and Ng, K.L. 1990. A Guide to the Freshwater Fishes of Singapore. Singapore Science Centre.
• National Parks Board (NParks). Freshwater Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/freshwater-fishes.