Mangrove Jack (Lutjanus argentimaculatus)

  Mangrove Jack (Lutjanus argentimaculatus)

A large individual found in Pasir Ris Park's mangroves which has seen some fighting with anglers. (Photograph by: Lumin Ong)

Family: Lutjanidae
Species Name: Lutjanus argentimaculatus
Common Name(s): Mangrove Jack, Mangrove Red Snapper

Presence in Singapore: Native
Habitat: Based on age - Adults: offshore coral reefs, Juveniles: Estuaries and rivers.
Conservation status: Near Threatened (Red Data Book 3)

The Mangrove Jack is a name known to many people as a game fish, food and even pets. This euryhaline fish covers a wide range of habitats depending on its age. Younger adults and juveniles inhabit inland waters such as estuaries and even freshwater streams, while adults move to deeper waters offshore over coral reefs. 

Growing up to a maximum size of 1.5 meters, this is a formidable predator in the ecosystems it occurs on whatever fits into its mouth. Like its relatives, it possesses sizable fangs that helps in snagging unsuspecting prey. It is an ambush predator, carefully inspecting and sneaking around shelters such as mangrove roots for its prey before catching them with a burst of speed.

As mentioned earlier, the Mangrove Jack is a popular commercial fish that is caught and farmed for its meat. It is also famous among fishermen for its burst of speed upon getting hooked.

A small Mangrove Jack found in full saltwater around Sentosa. (Photograph by: Lumin Ong)

References

• FishBase. Lutjanus argentimaculatus (Forsskål, 1775) – Mangrove Red Snapper. Retrieved from https://www.fishbase.se/summary/lutjanus-argentimaculatus.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.

Mangrove Cardinalfish (Yarica hyalosoma)

Mangrove Cardinalfish (Yarica hyalosoma)

A school of Mangrove Cardinalfish resting in the mouth of Sungei Cina. (Photograph by: Lumin Ong)

Family: Apogonidae

Species Name: Yarica hyalosoma
Common Name(s): Mangrove Cardinalfish, Humpbacked Cardinalfish

Presence in Singapore: Native
Habitat: Brackish such as estuaries and mangrove swamps. Enters the lower reaches of freshwater rivers as well.
Conservation status: Least Concern (Red Data Book 3)

The Mangrove Cardinalfish is a unique-looking fish that can be seen in freshwater to more commonly, brackish habitats. As its common name suggests, it can be found in our mangrove swamps, creeks and more during rising to high tide. It can be also seen in tidal rivers, river mouths and along the coast if it can't enter the mangrove forest due to low water levels.

The genus Yarica is said to include two species but so far, Y.hyalosoma seems to be the only widely recognized and documented species. It stands out from other cardinalfishes due to its habitat preferences and stocky build, which can reach 17cm in length. The Mangrove Cardinalfish is generally grey with a spot on both sides of the peduncle (base of tail). 

Being a cardinalfish, the Mangrove Cardinalfish is a predator with great eyesight due to its big eyes, picking off smaller fish and invertebrates in the water column with the help of its even bigger mouth. It is also a mouthbrooder just like its relatives.

A Mangrove Cardinalfish spotted in Sungei Buloh Wetland Reserve. (Photograph by: Lumin Ong)

References

• FishBase. Yarica hyalosoma (Bleeker, 1852) – Humpbacked Cardinalfish. Retrieved from https://www.fishbase.se/summary/Yarica-hyalosoma.
• 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.

Silver Moony (Monodactylus argenteus)

Silver Moony (Monodactylus argenteus)

A juvenile Silver Moony found in a pontoon. (Photography by: Lumin Ong)

Family: Monodactylidae
Species Name: Monodactylus argenteus
Common Name(s): Silver Moony, Diamondfish, Mono

Presence in Singapore: Native
Habitat: Coastal such as mangrove estuaries, tidal rivers and shallow reefs. Occasionally seen in lower freshwater stretches.
Conservation status: Near Threatened (Red Data Book 3)

The Silver Moony is a popular fish in the aquarium trade, especially for brackish aquariums but however, it is often advertised as a purely freshwater fish which isn't true. Being a euryhaline fish, the Silver Moony is relatively common in our coastal habitats ranging from brackish mangrove swamps to saltwater ones such as along seawalls, and in shallow reefs. 

Adult Silver Moonies can reach a maximum known length of 27cm but are usually half that size. Juveniles are more common in the upper reaches of their habitats while adults stay more at the coast. This is a unique-looking fish, being shaped like a diamond as its common name suggests with yellow fins standing out along its silver body. Very young juveniles are dark with orange fins.

They are known to form large schools but juveniles are usually solitary or found with a few other individuals. This fish is omnivorous, feeding on plankton, detritus and other small mid-water edibles. Interestingly, the juveniles are known to approach similar-sized and larger fishes in an attempt to "clean" them but are often met with annoyance.

A trio of very young Silver moonies.

A juvenile Silver Moony attempting to "clean" a Mangrove Cardinalfish.

References

• FishBase. Monodactylus argenteus (Linnaeus, 1758) – Silver Moony. Retrieved from https://www.fishbase.se/summary/Monodactylus-argenteus.
• 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.

 

Green Spotted Pufferfish (Dichotomyctere nigrovidis)

 Green Spotted Pufferfish (Dichotomyctere nigroviridis)

A Green Spotted Pufferfish at Admiralty Park during high tide. (Photograph by: Lumin Ong)

Family: Tetraodontidae
Species Name: Dichotomyctere nigroviridis
Common Name(s): Green Spotted Pufferfish

Presence in Singapore: Native
Habitat: Estuarine such as in mangrove swamps. Enters freshwater rivers and streams etc.
Conservation status: Least Concern (Red Data Book 3)

The Green Spotted Pufferfish is probably the most commonly seen pufferfish in Singapore as it is abundant in our mangrove habitats, which it enters during a rising tide. It is also a popular aquarium fish, where they're sold as freshwater fishes when they thrive much better in more saline waters. This pufferfish can grow up to 17cm but are usually seen at half that size. It is unique looking among its kind in Singapore, making it easy to identify thanks to its colouration and patternings.

Like all pufferfishes, the Green Spotted Pufferfish is mostly a hunter of hard-shelled invertebrates, which it uses its beak-like teeth to crush. It is not picky however and will even go for other fishes. When threatened by potential predators, they will puff up by inhaling water, revealing small spines all over the body in the process. Green Spotted Pufferfishes also contain the deadly tetrodotoxin which can kill if the fish is consumed.

A juvenile Green Spotted Pufferfish at the surface in Sungei Buloh Wetland Reserve.

References

• FishBase. Dichotomyctere nigroviridis (Marion de Procé, 1822) – Spotted Green Pufferfish. Retrieved from https://fishbase.se/summary/7763.
• 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.

Barramundi (Lates calcarifer)

Barramundi (Lates calcarifer)

A medium-sized Barramundi found patrolling in the shallow waters at Eagle Point.

Family: Latidae
Species Name: Lates calcarifer
Common Name(s): Barramundi, Asian Sea Bass, Giant Sea Perch

Presence in Singapore: Native
Habitat: Varied. Ranges from freshwater rivers to coastal habitats such as lagoons.
Conservation status: Data Deficient (Red Data Book 3), Least Concern (IUCN)

A fish most people should know, be it by name and/or taste. In Singapore, the Barramundi can be found in a variety of habitats with varying salinity such as lagoons, estuaries, freshwater and tidal rivers. The Barramundi is a large, predatory fish that have reached lengths of up to two meters on record. It hunts near the bottom for smaller fishes, crustaceans and molluscs as adults while the juveniles feed on zooplankton. It is a highly recognizable fish with its elongated body and sloping head, usually clad in grey of varying darkness. 

Adult Barramundi that usually reside in the upper reaches of freshwater habitats such as rivers migrate down to estuaries to breed. The juveniles then mature in coastal habitats such as mangrove swamps before repeating the cycle. Populations of Barramundi are known to establish in saltwater as well.

The Barramundi is an important food fish world wide and are raised in aquaculture across many countries including Singapore. It is also a popular sport fish due to the fight it's able to give anglers.

References

• FishBase. Lates calcarifer (Bloch, 1790) – Barramundi. Retrieved from https://www.fishbase.se/summary/Lates-calcarifer.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.

Indian Mud Moray (Gymnothorax tile)

 Indian Mud Moray (Gymnothorax tile)

An Indian Mud Moray found at the side of a tidal river during an upset in water chemistry.

Family: Muraenidae
Species Name: Gymnothorax tile
Common Name(s): Indian Mud Moray

Presence in Singapore: Native
Habitat: Muddy estuaries, mangrove swamps, river mouths.
Conservation status: Least Concern (Red Data Book 3)

This moray eel is abundant in our estuaries but in true moray eel fashion, it is tough to find due to its elusive nature and that their habitats are usually muddy. Due to its euryhaline nature, it is often sold as a freshwater in the aquarium trade but it thrives much better and longer in brackish water. Growing to a length of 60cm, the Indian Mud Moray preys on other fishes and crustaceans which it uses its strong sense of smell to locate, making up for their poor eyesight. It also has a recognizable look among local moray eels, exhibiting a dirty brown base colour with tiny, yellow speckles.

Like all moray eels, the Indian Mud Moray possesses two sets of jaws: 1. the oral jaw which is used to do the initial grasping of prey and 2. a pharyngeal jaw resting inside that helps to pull the prey in or tear off chunks. 

Another Indian Mud Moray found at the side of a tidal river during an upset in water chemistry.  It is sharing the space with its prey - a Penaeid prawn, showing the direness of the situation.

References

• FishBase. Gymnothorax tile (Hamilton, 1822) – Freshwater Moray. Retrieved from https://www.fishbase.se/summary/Gymnothorax-tile.
• 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.

Mangrove Pipefish (Ichthyocampus carce)

Mangrove Pipefish (Ichthyocampus carce)

A large-sized Mangrove Pipefish compared to an usual-sized individual!

Family: Syngnathidae

Species Name: Ichthyocampus carce
Common Name(s): Mangrove Pipefish, Freshwater Pipefish, Indian Freshwater Pipefish

Presence in Singapore: Native
Habitat: Mangroves and estuaries, slow-moving to still water such as pools. Freshwater streams and rivers.
Conservation status: Vulnerable (Red Data Book 3)

One of the few estuarine Syngnathid (seahorses and pipefishes) that we can find in Singapore and the most readily seen too. It can be found in relative abundance during low tide, where it inhabits isolated pools and slow-moving creeks. Despite their numbers, their thin bodies and brown colouration makes them tough to spot. They can grow up to 15cm in length but are usually found at sizes half of that, adding on to the difficulty. 

For a fish with such a seemingly small mouth, they are voracious predators of small invertebrates and zooplankton, which they snake along the sediment or around mangrove roots to stalk.

Like all Syngnathids, the males raises the eggs. The male Mangrove Pipefish carries the eggs in a brood pouch found under the tail.

One out of several Mangrove Pipefish found in an isolated pool with many estuarine gobies.

References

• ​FishBase. Ichthyocampus carce (Hamilton, 1822) – Freshwater Pipefish. Retrieved from https://www.fishbase.se/summary/Ichthyocampus-carce.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.
• Ong JXL & Tay JX (2024) Biodiversity Record: Fish fauna of a mangrove tide pool at Sungei Buloh. Nature in Singapore, 17: e2024056. DOI: 10.26107/NIS-2024-0056
• National Parks Board (NParks). Marine Fishes. Retrieved from https://www.nparks.gov.sg/nature/species-list/marine-fishes.

Milkfish (Chanos chanos)

Milkfish (Chanos chanos)

A school of Milkfish at Sungei Buloh Wetland Reserve's main bridge.

Family: Chanidae
Species Name: Chanos chanos
Common Name(s): Milkfish

Presence in Singapore: Native
Habitat: Coastal and offshore waters, often enters esutaries.
Conservation status: Least Concern (Red Data Book 3)

Although adults live offshore, Milkfish are known to frequently enter shallow coastal waters and estuaries, sometimes touching freshwater. They can be commonly seen in schools during the rising and high tide in habitats such as tidal rivers, where they sometimes mix with mullets. These are sizable fishes, growing to a maximum length of 1.8 meters but usually average out at a meter and are recognizable by their deeply forked tail.

Having a small mouth, Milkfish are omnivorous and feed on a variety of pelagic organisms such as zooplankton and fish larvae. They also feed near the bottom on benthic invertebrates, algae and even detritus. Milkfish themselves are important food fish for humans and are farmed as well. 

The Milkfish is the sole-living representative of the family Chanidae, which includes several extinct genera that existed during the Cretaceous. 

Adult Milkfish spawn in the sea, where the maturing juveniles swim back to coastal waters or even further upstream to grow. 

A small Milkfish following a school of mullets.

References

• FishBase. Chanos chanos (Fabricius, 1775) – Milkfish. Retrieved from https://www.fishbase.se/summary/chanos-chanos.
• 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.

Javanese Ricefish (Oryzias javanicus)

Javanese Ricefish (Oryzias javanicus)

A school of Javanese Ricefish at Pasir Ris Park's Mangrove Boardwalk (Photograph by: Lumin Ong)

Family: Adrianichthyidae
Species Name: Oryzias javanicus
Common Name(s): Javanese Ricefish

Presence in Singapore: Native
Habitat: Various brackish and freshwater habitats like mangrove swamps and canals.
Conservation status: Least Concern (Red Data Book 3)

A small but very adaptable fish commonly seen in not only our estuaries, but sometimes also in freshwater as well. The Javanese Ricefish can be found in schools of varying sizes and are recognizable by their guppy-like appearance. They have a distinct yellow ring around their tail which helps to separate them from other ricefish species found in the region.

Growing to a maximum size of 4.5cm, the Javanese Ricefish is mainly a micropredator of tiny crustaceans and protozoa but are known to consume detritus and algae too. 

The female carries her eggs outside her genital pore via filaments.

A Javanese Ricefish at Eagle Point during a rising tide.

References

• FishBase. Oryzias javanicus (Bleeker, 1854) – Javanese Ricefish. Retrieved from https://www.fishbase.se/summary/Oryzias-javanicus.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.

Shortnose River Garfish (Zenarchopterus gilli)

 Shortnose River Garfish (Zenarchopterus gilli)

A male Shortnose River Garfish exhibiting a shorter and wider lower jaw, no dorsal stripe, enlarged andropodium (visible below the tail). (Photograph by: Lumin Ong)

Family: Zenarchopteridae
Species Name(s): Zenarchopterus gilli, Zenarchopterus kneri
Common Name(s): Shortnose River Garfish, Viviparous Halfbeak

Presence in Singapore: Native
Habitat: Estuaries, also occurs in full saltwater along the coast
Conservation status: Data Deficient (Red Data Book 3)

The Shortnose River Garfish is not well-known in Singapore as it is often overlooked by the popular Stripe-nosed Halfbeak (Zenarchopterus buffonis). Based on observations, it is less commonly seen but is still reasonably abundant in our coastal habitats like estuaries. It is found mainly in brackish and saltwater but are known to travel up tidal rivers into lower salinity ranges. This fish can reach a maximum length of 20cm but is usually found half that size. 

As a halfbeak, its lower jaw is much longer than its upper jaw, which aids in feeding at the surface as it forages for fallen insects and other organic matter. Being in the family Zenarchopteridae (Viviparous Halfbeaks), this species is ovoviviparous where the eggs are fertilized and hatch internally.

To differentiate it from the very similar looking Stripe-nosed Halfbeak, here are two  features:

1. The Shortnose River Garfish lacks the bold dorsal stripe seen in the Stripe-nosed Halfbeak. If present however, the stripe is generally diffused and not extensive.
2. The Shortnose River Garfish has a notably shorter and wider lower jaw, giving it a less elongated appearance.
   

For utmost accuracy however, it's best to look at the andropodium (modified anal fin used to deliver sperm to females) of the males:

Stripe-nosed Halfbeak - small andropodium barely or not reaching the base of the tail.
Shortnose River Garfish - enlarged andropodium reaching the tip of the tail.

The Shortnose River Garfish is also noted to occasionally have an orange dorsal fin but we're not sure if this applies to the Stripe-nosed Halfbeak as well.

A small school of Shortnose River Garfish. (Photograph by: Lumin Ong)

References

• FishBase. Zenarchopterus gilli Smith, 1945 – Viviparous Halfbeak. Retrieved from https://fishbase.mnhn.fr/summary/Zenarchopterus-gilli.html.
• FishBase. Zenarchopterus buffonis (Valenciennes, 1847) – Buffon's River-garfish. Retrieved from https://www.fishbase.se/summary/17041.
• 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.

Stripe-nosed Halfbeak (Zenarchopterus buffonis)

Stripe-nosed Halfbeak (Zenarchopterus buffonis)

A small school of Stripe-nosed Halfbeaks found in Pasir Ris Park's Mangrove Boardwalk during high tide. (Photograph by: Lumin Ong)

Family: Zenarchopteridae
Species Name: Zenarchopterus buffonis
Common Name(s): Stripe-nosed Halfbeak, Buffon's River-garfish

Presence in Singapore: Native
Habitat: Estuaries, also occurs in full saltwater along the coast
Conservation status: Least Concern (Red Data Book 3)

A common and usual sight in our estuaries and other coastal habitats, this surface-dwelling fish is usually sighted in schools of varying numbers. It is also known to travel up tidal rivers. Although capable of reaching 23cm in length, this fish is usually seen half that size. As a halfbeak, its lower jaw is much longer than its upper jaw, which aids in feeding at the surface as it forages for fallen insects and other organic matter. Being in the family Zenarchopteridae (Viviparous Halfbeaks), this species is ovoviviparous where the eggs are fertilized and hatch internally.

It is very similar-looking to the lesser-known Shortnose River Garfish (Zenarchopterus gilli).  In general, the Stripe-nosed Halfbeak has a bold stripe that stretches at least past the head, which is missing or very faded in the Shortnose River Garfish. The lower jaw of the Stripe-nosed Halfbeak is also thinner and longer compared to the Shortnose River Garfish. The tip of both species' lower jar is shiny and bright.

To be more accurate, one must look at the male's andropodium (a modified anal fin used to deliver sperm to the females):

Stripe-nosed Halfbeak - small andropodium barely or not reaching the base of the tail.
Shortnose River Garfish - enlarged andropodium reaching the tip of the tail.

The juvenile Stripe-nosed Halfbeak has two solid white bands as seen below.

References

• FishBase. Zenarchopterus gilli Smith, 1945 – Viviparous Halfbeak. Retrieved from https://fishbase.mnhn.fr/summary/Zenarchopterus-gilli.html.
• FishBase. Zenarchopterus gilli Smith, 1945 – Viviparous Halfbeak. Retrieved from https://fishbase.mnhn.fr/summary/Zenarchopterus-gilli.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.

Spot-tail Needlefish (Strongylura strongylura)

Spot-tail Needlefish (Strongylura strongylura)

A small school of Spot-tail Needlefishes seen at Eagle Point.

Family: Belonidae
Species Name: Strongylura strongylura
Common Name(s): Spot-tail Needlefish, Blackspot Longtom

Presence in Singapore: Native
Habitat: Coastal waters lined with mangrove forests, known to enter freshwater.
Conservation status: Near Threatened (Red Data Book 3), presumably abundant

A fierce-looking fish commonly seen patrolling the edge of mangrove forests along the coast. The Spot-tail Needlefish can be differentiated from its relatives by having a spot at the base of its round, yellow tail. This fish can reach up to lengths of around 40cm. Predatory in nature, its needle-like mouth is lined with sharp teeth, which aids in securing small prey such as other fishes and crustaceans. 

Based on observations, it is known to travel into mangrove swamps and even upstream into freshwater to look for food. However, it seems to prefer waiting by the shoreline during receding tides, which are when most pelagic fishes return out to sea. The lowering water levels also reduce the space given for prey to escape this surface-dwelling predator.

Diseased individuals are noted to display dark patches and dull colouration.

A Spot-tail Needlefish swallowing a shrimp.

References

• 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.

Squaretail Mullet (Ellochelon vaigiensis)

Squaretail Mullet (Ellochelon vaigiensis)

    A large Squaretail Mullet seen at Bukit Chermin Boardwalk.

Family: Mugilidae
Species Name: Ellochelon vaigiensis
Common Name(s): Squaretail Mullet

Presence in Singapore: Native 
Habitat: Freshwater, brackish water and saltwater habitats. Commonly seen in estuarine habitats like tidal rivers.
Conservation status: Least Concern (Red Data Book 3)

This is a unique-looking mullet that can be commonly seen in Singapore's coastal habitats. It is very recognizable by its fins' yellow edges and smaller individuals would have silvery patches flanked by black ones on the top of its body. As its name suggests, it has a rather squarish tail as opposed to the usually seen vaguely forked tails in other mullets. This species has a maximum recorded length of 63 cm but unconfirmed sources suggest larger sizes. 

Predominantly a surface dweller, this omnivorous fish feeds on algae, detritus and other organic matter. Being a euryhaline fish, it is able to adapt to salinities ranging from freshwater to saltwater, hence the diverse habitats it can be found in. They return to the sea to spawn, laying eggs that are free-floating. 

Several small Squaretail Mullets presumably feeding at the surface at Eagle Point.

References

• 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.

Sea Mullet (Mugil cephalus)

Sea Mullet (Mugil cephalus)

A close view at a Sea Mullet found in Sungei Buloh Wetland Reserve.

Family: Mugilidae
Species Name: Mugil cephalus
Common Name(s): Sea Mullet, Grey Mullet, Flathead Mullet

Presence in Singapore: Native 
Habitat: Freshwater, brackish water and saltwater habitats. Commonly seen in estuarine habitats like tidal rivers.
Conservation status: Data Deficient (Red Data Book 3), presumably abundant

This is one of the more well-known mullets in Singapore as it is commonly seen and photographed at Sungei Buloh Wetland Reserve. This is a large species capable of growing up to a meter in length. Despite its similar build and appearance to other mullets in the same habitat such as species under the genus Planiliza, it can be identified via its extensive adipose eyelids (the fatty, transparent layer over its eye) and a blue spot at the base of its pectoral fins. Its overall colour is a dull to dark grey with a hint of blue or green.

This species can commonly be seen travelling through tidal rivers such as at Sungei Buloh Wetland Reserve and Sungei Tampines especially during a rising to high tide. It is a euryhaline fish, being able to adapt to various salinities ranging from freshwater to seawater but they return to the sea to breed. The Sea Mullet is omnivorous and feeds near the bottom, sifting through sediment for algae, detritus and other organic matter. 

When threatened by predators, a school of Sea Mullets would leap out the water at high speeds. They also leap singly out of the water to rid themselves of irritants such as parasites. Globally, it is an important food fish.

A school of Sea Mullets in their usual colouration at Sungei Buloh Wetland Reserve. (Photograph by: Lumin Ong)

A Sea Mullet leaping out the water to presumably get rid of parasites.

References

• 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.

Spotted Scat (Scatophagus argus)

Spotted Scat (Scatophagus argus)

Several adult Spotted Scats grazing under a pontoon along our southern shores (Photograph: By Lumin Ong)

Family: Scatophagidae

Species Name: Scatophagus argus
Common Name(s): Spotted Scat

Presence in Singapore: Native
Habitat: Coastal habitats such as estuaries, seawalls and more.
Conservation status: Least Concern (Red Data Book 3)

The only one of its kind in Singapore, the Spotted Scat is an easily recognizable fish due to its rectangular body covered in spots and steep, slanting head. This fish can grow to a length of almost 40cm. While the adults have spots, the juveniles can have either spots or stripes and display a little red. Juveniles are more often seen in brackish and freshwater habitats such as mangrove swamps, while adults can be seen further out in saltwater along the coast. 

Although named after the belief it feeds mainly on scat, the Spotted Scat is mostly herbivorous, grazing on algae and plant matter with no evidence they feed on fecal matter. For protection, Spotted Scats possess venomous spines in its fins that can inflict significant pain and side effects such as dizziness. This species is also a schooling fish.

A school of juvenile Spotted Scats displaying their spines to an approaching Moses' Snapper. Note the striped patterning of the juveniles.

Another school of juvenile Spotted Scats, this time with spots instead of stripes. (Photography by: Lumin Ong)



References

• 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.

Spotted Archerfish (Toxotes chatareus)

Spotted Archerfish (Toxotes chatareus)

A matured Spotted Archerfish found along a seawall at out southern shores.

Family: Toxotidae

Species Name: Toxotes chatareus
Common Name(s): Spotted Archerfish

Presence in Singapore: Native
Habitat: Mangrove swamps, tidal rivers and other coastal habitats with varying salinity.
Conservation status: Near Threatened (Red Data Book 3)

Archerfishes are one of the most popular fishes in the world, renowned for their ability to shoot jets of water at prey outside of water. To shoot down prey, an archerfish would place their tongue against the roof of its mouth to form a tube, which it then closes its gill operculum at high speeds to force water through. It is suggested that archerfishes are able to compensate for the refraction and process targets in three-dimension. All archerfishes share the same deep-bodied build, with a large superior (upward-facing) mouth fitting its lifestyle.

Of the two archerfish species in Singapore, the Spotted Archerfish is uncommon and usually seen singly. This is one of the larger archerfish species, growing to a maximum length of around 40cm. In upstream habitats and mangrove swamps, the Spotted Archerfish forages for insects above water to shoot down similar to the Banded Archerfish. They are omnivorous with an opportunistic diet which changes depending on location. Further out to sea, they feed on crustaceans, plant matter and smaller fishes. 

A juvenile Spotted Archerfish found alone in the presence of other fishes with no Banded Archerfishes in sight at Sungei Buloh Wetland Reserve's Eagle Point.

Interestingly, the Spotted Archerfish seems to be more tolerant of strong water currents than the Banded Archerfish. It can be seen swimming alone out in the open while its relatives take shelter at the sides or along structures during a changing tide. Spotted Archerfishes are also less common upstream in freshwater, being found more often in estuarine habitats and sometimes even saltwater.

They can be differentiated from the Banded Archerfish (Toxotes jaculatrix) by usually having bright, golden-yellow eyes and spots with alternating sizes.

 

A Spotted Archerfish next to a Banded Archerfish at Sungei Buloh Wetland Reserve. Spot the differences!

References

• 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.

Banded Archerfish (Toxotes jaculatrix)

Banded Archerfish (Toxotes jaculatrix)

A school of Banded Archerfish found in Sungei Buloh Wetland Reserve. (Photograph by: Lumin Ong)

Family: Toxotidae
Species Name: Toxotes jaculatrix
Common Name(s): Banded Archerfish

Presence in Singapore: Native
Habitat: Mangrove swamps, tidal rivers and other coastal habitats with varying salinity.
Conservation status: Least Concern (Red Data Book 3)

Archerfishes are one of the most popular fishes in the world, renowned for their ability to shoot jets of water at prey outside of water. To shoot down prey, an archerfish would place their tongue against the roof of its mouth to form a tube, which it then closes its gill operculum at high speeds to force water through. It is suggested that archerfishes are able to compensate for the refraction and process targets in three-dimension. All archerfishes share the same deep-bodied build, with a large superior (upward-facing) mouth fitting its lifestyle.

In Singapore, there are two species of archerfishes in Singapore with the Banded Archerfish being the most commonly encountered. They can get rather large for an archerfish, growing up to 30cm in length. They are abundant in mangrove swamps where they patrol among the roots during high tide for prey such as insects to shoot down. They are omnivorous and opportunistic feeders of other foodstuffs at the surface. During a changing tide, they would stick to the sides or near structures to take shelter from the currents. 

Several Banded Archerfishes taking shelter under the main bridge at Sungei Buloh Wetland Reserve during a changing tide. (Photograph by: Tay Jing Xuan)

Aside from mangrove swamps, they can also be found further upstream in freshwater and out in saltwater along the coasts. They can be differentiated from the Spotted Archerfish (Toxotes chatareus) via their dull-coloured eyes and their even-sized, large black blotches. The patterning of juveniles are complete stripes that reach from top to bottom.

A school of Banded Archerfishes found along a seawall at our southern shores. (Photograph by: Tay Jing Xuan)

 

A juvenile Banded Archerfish found in Pasir Ris Park's mangroves. (Photograph by: Lumin Ong)

References

• 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.