Crescent Grunter (Terapon jarbua)

Crescent Grunter (Terapon jarbua)

A school of Crescent Grunters investigating a fallen snake shed in Berlayer Creek.

Family: Terapontidae

Species Name(s): Terapon jarbua

Common Name(s): Crescent Grunter, Target Fish, Spiky Trumpeter, Tiger Perch
Presence in Singapore: Native

Habitat: Freshwater to Marine.
Conservation status: Least Concern (Red Data Book 3)

The Crescent Grunter is a euryhaline fish that can be found in a wide range of salinities from full marine to freshwater. It spawns in saltwater, where juveniles hang out in intertidal zones but also swim up estuaries and rivers alongside adults. This commonly sighted fish can grow to a maximum known length of 36cm but usually average around 25cm. This species' distinctive patterning especially from the top gives it one of its many common names - the Target Fish.

This fish is mostly carnivorous, hunting invertebrates and smaller fish near the bottom but will also eat algae. They are also known ectoparasites, feeding on the scales of larger fishes which makes them horrible community fishes in most aquariums. Commercially, this fish is sold usually fresh or dry and salted.

Adult males guard and fan their eggs. Juveniles are also known to be territorial and establish territories via excavating craters. The name "Grunter" and "Trumpeter" comes from their ability to make noise using their swim bladder, which they use for communication.



References

• FishBase. Terapon jarbua (Fabricius, 1775) – (Jarbua terapon). Retrieved from https://fishbase.se/summary/Terapon_jarbua.html
• Lim, K.K.P. & Low, J.K.Y. 1998. A Guide to Common Marine Fishes of Singapore. Singapore Science Centre, 163 pp. ISBN 981-00-9904-5.
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.

Grey Knight Goby (Stigmatogobius sadanundio)

Grey Knight Goby (Stigmatogobius sadanundio)

A pair of Grey Knight Gobies hovering in a mangrove creek in Pasir Ris. (Photograph by: Lumin Ong)

Family: Oxudercidae: Gobionellinae

Species Name(s): Stigmatogobius sadanundio
Common Name(s): Grey Knight Goby

Presence in Singapore: Native
Habitat: Brackish and freshwater. Mangrove creeks and pools.
Conservation status: Least Concern (Red Data Book 3)

This is one of the more prominent mangrove gobies one will spot from above water due to its size! The Grey Knight Goby is decently-sized compared to its neighbours and grow to a maximum known length of 9cm. It is common and often seen hovering in shallow mangrove creeks and pools during low tide. 

It is known to prefer lower salinity levels and are more abundant in the back mangroves, with younger individuals being spotted in freshwater. This carnivorous species is an active predator which feeds on smaller fish and invertebrates. Its rarer cousin, the Peach Knight Goby (Stigmatogobius pleurostigma) can look similar and would require a clear view of the tail for identification. A solid spot would be present at the bottom of the tail for that species! 

The Grey Knight Goby is also a commonly sold aquarium fish and is frequently included in brackish community tanks.

A large Grey Knight Goby - note the lack of solid spot at the bottom of the tail.

A small juvenile found in a freshwater drain on Pulau Ubin.

References

• FishBase. Stigmatogobius sadanundio (Hamilton, 1822) – (Knight goby). Retrieved from https://www.fishbase.se/summary/Stigmatogobius-sadanundio.html
• Lim, K.K.P. & Low, J.K.Y. 1998. A Guide to Common Marine Fishes of Singapore. Singapore Science Centre, 163 pp. ISBN 981-00-9904-5.
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.

Snubnose Gobies (Pseudogobius sp.)

Snubnose Gobies (Pseudogobius sp.)

The most commonly seen snubnose goby - Pseudogobius poicilosoma.

Family: Oxudercidae: Gobionellinae

Habitat: Brackish to freshwater. Mudflats, tidal creeks, mangrove pools etc.

The genus Pseudogobius has 7 species recorded in the third edition of Singapore's Red Data Book. These gobies are usually small, averaging out between 2 and 6cm. Species such as the Spotted Snubnose Goby (Pseudogobius poicilosoma) can be found in almost every estuarine habitat across different salinity ranges, while other species such as Pseudogobius melanosticta appear to prefer near freshwater salinity. All species pick small invertebrates off the sediment or whatever surface they're on. 

1. Spotted Snubnose Goby (Pseudogobius poicilosoma)

Blue arrow: the blue dot on the dorsal fin that makes this species easy to ID!

Species Name(s): Pseudogobius poicilosoma
Common Name(s): Spotted Snubnose Goby, Northern Fatnose Goby

Presence in Singapore: Native
Habitat: Various estuarine habitats from near freshwater to full marine salinity.
Conservation status: Least Concern (Red Data Book 3)

This is the most abundant snubnose goby one will encounter in our estuaries and also one of the most common gobies too. An ideal angle would reveal a blue dot on the dorsal fin, which distinguishes this species from the rest. The vertical black stripes and lack of a yellow peduncle also helps narrow down this species.

2. Blackline Snubnose Goby (Pseudogobius verticalis)

A Blackline Snubnose Goby displaying the yellow peduncle and dorsal fin colouration.

Species Name(s): Pseudogobius verticalis
Common Name(s): Blackline Snubnose Goby

Presence in Singapore: Native
Habitat: Brackish. Mangrove pools and creeks.
Conservation status: Near Threatened (Red Data Book 3)

This species is often seen alongside the Spotted Snubnose Goby and similar-looking Yellowfin Snubnose Goby (Pseudogobius fulvicaudus). 

Both the Blackline Snubnose Goby and Yellowfin Snubnose Goby possess a yellow peduncle, alongside fins with significant portions of yellow. The first dorsal fine of the Blackline Snubnose Goby is a vertical stripe of black against yellow something like the photo on the right. 

A relatively colourful Blackline Snubnose Goby showing off its fins!

3. Yellowfin Snubnose Goby (Pseudogobius fulvicaudus)

A Yellowfin Snubnose Goby flaring at another individual, showing off the ID features!

Species Name(s): Pseudogobius fulvicaudus
Common Name(s): Yellowfin Snubnose Goby

Presence in Singapore: Native
Habitat: Brackish. Mangrove pools and creeks.
Conservation status: Near Threatened (Red Data Book 3)

Another colourful snubnose goby that is similar-looking to the Blackline Snubnose Goby, which it shares a yellow peduncle with. The first dorsal fin has a horizontal 
yellow stripe in the middle of two black stripes as shown on the right.

A closer look at the Yellowfin Snubnose Goby.

4. Black-spotted Snubnose Goby (Pseudogobius melanosticta)

A Black-spotted Snubnose Goby showing off its black cheek stripes.

Species Name(s): Pseudogobius melanosticta
Common Name(s): Black-spotted Snubnose Goby

Presence in Singapore: Native
Habitat: Brackish, near freshwater. Mangrove pools and creeks.
Conservation status: Near Threatened (Red Data Book 3)

A lesser seen snubnose goby but distinct from the rest presented so far. This species is noted to inhabit salinities nearer to freshwater. The black cheek stripe is slanted in this species and the dorsal fin is tall, with two black stripes ending in black blotch at the end. 

A Black-spotted Snubnose Goby displaying its tall dorsal fin clearly! (Photograph by: Zick Soh)

5. Avicennia Snubnose Goby (Pseudogobius avicennia)

Species Name(s): Pseudogobius avicennia

Common Name(s): Avicennia Snubnose Goby

Presence in Singapore: Native
Habitat: Brackish. Mangrove fringes, pools and creeks.
Conservation status: Near Threatened (Red Data Book 3)

Another lesser seen species of snubnose goby thought to prefer living near and along the fringes of mangroves. This species is identified by the presence of a distinct, black ocellus on the peduncle (labelled with a white arrow on the right).

This species has been observed foraging on mangrove roots during high tide as seen in https://www.inaturalist.org/observations/316740558. 

Not yet encountered:

• Masago Snubnose Goby (Pseudogobius masago)
• Barfin Snubnose Goby (Pseudogobius yanamensis)

 


References

• Larson, H. K., & Hammer, M. P. (2021). A revision of the gobiid fish genus Pseudogobius (Teleostei: Gobiidae: Tridentigerinae), with description of seven new species from Australia and South-east Asia.
• Lim, K.K.P. & Low, J.K.Y. 1998. A Guide to Common Marine Fishes of Singapore. Singapore Science Centre, 163 pp. ISBN 981-00-9904-5.
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.
• Ong JXL (2024) Biodiversity Record: Gobies in mangrove tide pools at Sungei Buloh Wetland Reserve. Nature in Singapore, 17: e2024035. DOI: 10.26107/NIS-2024-0035
• Ong JXL (2025) Biodiversity Record: Aggressive conspecific interactions of two species of mangrove gobies. Nature in Singapore, 18: e2025040. DOI: 10.26107/NIS-2025-0040

Roux's Dwarf Goby (Pandaka rouxi)

Roux's Dwarf Goby (Pandaka rouxi)

A lone Roux's Dwarf Goby seen in Pasir Ris Park.

Family: Oxudercidae: Gobionellinae

Species Name(s): Pandaka rouxi
Common Name(s): Roux's Dwarf Goby, Roux's Pygmy Goby

Presence in Singapore: Native
Habitat: Brackish. Mangrove creeks and pools.
Conservation status: Near Threatened (Red Data Book 3)

This is one of our smallest native fishes! They are only rivalled by glass gobies in the genus Gobiopterus. The largest known individual reached a length of 1.8cm but they usually average out at just 1cm. They can be found freely swimming in mangrove creeks and pools, where their salinity preference is brackish.

They are closely related to bumblebee gobies of the genus Brachygobius and are also similiar in appearance. They are definitely smaller however, with incomplete stripes and blots alongside an mostly orange dorsal fin. At this size, they usually feed on zooplankton.

They are occasionally available in the aquarium trade as an interesting choice for nano aquariums. They do not live long in freshwater. 

A mix of Kabili Bumblebee Gobies, Glass Gobies and a lone Roux's Dwarf Goby circled in blue.

References

• Aquarium Glaser GmbH. Pandaka rouxi – (dwarf goby). Retrieved from https://www.aquariumglaser.de/en/25-perchlike-fishes/pandaka-rouxi-2/
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.

Blue-eyed Mullet-goby (Hemigobius melanurus)

 Blue-eyed Mullet-goby (Hemigobius melanurus)

A mature Blue-eyed Mullet-goby found in a mangrove pool in Admiralty Park.

Family: Oxudercidae: Gobionellinae

Species Name(s): Hemigobius melanurus, Hemigobius mingi
Common Name(s): Blue-eyed Mullet-goby, Banded Goby

Presence in Singapore: Native
Habitat: Brackish but also inhabits freshwater. Mangrove creeks and pools.
Conservation status: Near Threatened (Red Data Book 3)

The Blue-eyed Mullet-goby is common in our mangrove forests, being found easiest in creeks and pools revealed during low tide. It makes itself rather visible by hanging out near the surface, staring at the sky like it's in a daze. It seems to prefer living in the back half of the mangroves, where the salinity is a closer to freshwater but is adaptable like most estuarine gobies.

Mature individuals have a unique dirty brown with bands that fade past halfway down the body. Juveniles can be confused for bumblebee gobies in the genus Brachygobius, but have possess more bands which are thinner and also orange dorsal fins. This goby has been observed grazing on surfaces but are also known to be opportunistic feeders on small invertebrates.

*It is noted that Hemigobius melanurus is synonymous with Hemigobius mingi.

A mature Blue-eyed Mullet-goby grazing on a mangrove root, offering a lateral view.

A juvenile Blue-eyed Mullet-goby displaying behaviour typical of this species - staring at the sky.

References

• Larson, H. K. (1999). A Review of the Mangrove Goby Genus Hemigobius (Gobioidei, Gobiidae, Gobionellinae). The Beagle, Records of the Museums and Art Galleries of the Northern Territory, 15, 23–42. Retrieved from https://www.researchgate.net/publication/354335932_A_Review_of_the_Mangrove_Goby_Genus_Hemigoius_Gobioidei_Gobiidae_Gobionellinae
• Lim, K.K.P. & Low, J.K.Y. 1998. A Guide to Common Marine Fishes of Singapore. Singapore Science Centre, 163 pp. ISBN 981-00-9904-5.
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.
• World Register of Marine Species (WoRMS). Hemigobius melanurus (Bleeker, 1849). Retrieved from https://www.marinespecies.org/aphia.php?p=taxdetails&id=314573