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.

Grey-Banded Sand Loach (Nemacheilus selangoricus)

Grey-Banded Sand Loach (Nemacheilus selangoricus)

A pair of Grey-banded Sand Loaches found in a sandy forest stream in Bintan. (Photograph by: Jiayuan Lin)

Family: Nemacheilidae

Species Name: Nemacheilus selangoricus 
Common Name: Grey-Banded Sand Loach, Grey-Banded Loach
Presence in Singapore: Native
Habitat: Sandy freshwater forest streams
Conservation Status: Critically Endangered (Red Data Book 3)

The Grey-Banded Sand Loach is rarely seen in Singapore, where it is restricted to a small area in the Central Catchment Nature Reserve. Unlike other fishes found in forests, the Grey-Banded Sand Loach prefers clear, sandy forest streams that have little vegetation. It is a small fish growing to around 6cm on average in length. They use their barbels to feel for foodstuffs such as small invertebrates among the substrate. It is critically endangered in Singapore as it is threatened by habitat loss and the presence of invasive species.

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.

Spotted Eel-Loach (Pangio muraeniformis)

Spotted Eel-Loach (Pangio muraeniformis)

A Spotted-Eel Loach found at the side of a forest stream in Bintan. (Photograph by: Jiayuan Lin)

Family: Cobitidae

Species Name: Pangio muraeniformis
Common Name: Spotted Eel-Loach
Presence in Singapore: Native
Habitat: Freshwater forest streams
Conservation Status: Critically Endangered (Red Data Book 3)

The Spotted Eel-Loach belongs to the genus Pangio, which includes popular aquarium fishes such as Pangio kuhlii and Pangio semicincta. While they're called eel-loaches, they are more famously generalized as "kuhli loaches" or even "coolie loaches". The Spotted Eel-Loach is rarely seen in Singapore, where it is restricted to the Nee Soon Swamp Forest and its surroundings. It inhabits acidic forest streams where they stick to the bottom or the sides.

Growing up to 8cm, this appropriately named eel-like fish forages and hide among the sediment and leaf litter. They use their small barbels to search for foodstuffs such as small invertebrates. To protect themselves, eel-loaches have a spine under each eye that protrude when threatened by a predator. 

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.

Hasselt's Leaf Catfish (Silurichthys hasseltii)

Hasselt's Leaf Catfish (Silurichthys hasseltii)

A Hasselt's Leaf Catfish found in a shallow, fast-flowing forest stream.

Family: Siluridae

Species Name: Silurichthys hasseltii
Common Name: Hasselt's Leaf Catfish
Presence in Singapore: Native
Habitat: Freshwater forest streams and pools
Conservation Status: Critically Endangered (Red Data Book 3)

The Hasselt's Leaf Catfish is rarely seen in Singapore, where it is restricted to the Nee Soon Swamp Forest and its surroundings. It inhabits acidic forest streams and juveniles have been found in shallow forest pools. This nocturnal fish is highly photosensitive, making it tough to observe and photograph. This fish grows up to around 14cm in length and its tail is fused to the long anal fin, making it seem eel-like when it swims.

It is recognizable by a pair of long barbels, which it uses to forage at the surface for fallen insects and other prey. In the day, it hides among vegetation such as leaf litter and roots. In Singapore, it is critically endangered as it is threatened by habitat loss and the presence of invasive species.

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.

Sunda Leaf Fish (Nandus nebulosus)

Sunda Leaf Fish (Nandus nebulosus)

A small Sunda Leaf Fish found in a murky catchment fed by a forest stream.

Family: Nandidae

Species Name: Nandus nebulosus
Common Name: Sunda Leaf Fish, Bornean Leaf Fish, Malayan Leaf Fish
Presence in Singapore: Native
Habitat: Freshwater forest streams, catchment, forest pools
Conservation Status: Endangered (Red Data Book 3)

The Sunda Leaf Fish is an uncommon, unique-looking species found more in the Bukit Timah Nature Reserve. It can be found in a variety of stagnant and slow-moving water bodies such as forest pools, streams and larger catchments. As its name suggests, its body shape and colours allow it to mimic a dead leaf, making it appropriately camouflaged for its habitats and that makes it tough to find. Growing up to 12cm in length, this predatory fish uses its disguise
to ambush smaller fish and invertebrates. 

(All photographs by: Jiayuan Lin)

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.

Buff-backed Spiny Eel (Macrognathus maculatus)

Buff-backed Spiny Eel (Macrognathus maculatus)

A small Buff-backed Spiny Eel found foraging in a slow-moving forest stream.

Family: Mastacembelidae

Species Name: Macrognathus maculatus
Common Name: Buff-backed Spiny Eel
Presence in Singapore: Native
Habitat: Freshwater forest streams
Conservation Status: Critically Endangered (Red Data Book 3)

The Buff-backed Spiny Eel is a rarely seen species in Singapore where it is restricted to the Nee Soon Swamp Forest and its surroundings. This eel is recognized by its relatively long snout typical of spiny eels and having a brown, mottled body. It can grow up to 28cm long but is usually found at half that length or less.

This nocturnal fish hides among vegetation and in the substrate during the day. It emerges at night, poking around the sediment to search for small invertebrates that can fit in its also small mouth. It is critically endangered in Singapore as it is threatened by habitat loss and the presence of invasive species.

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.

Sunda Swamp Eel (Monopterus javanensis)

Sunda Swamp Eel (Monopterus javanensis)

A juvenile Sunda Swamp Eel found in a waterlogged grass patch by a road.

Family: Symbranchidae

Species Name: Monopterus javanensis
Common Name: Sunda Swamp Eel
Presence in Singapore: Native
Habitat: Various freshwater habitats such as streams, ponds and canals.
Conservation Status: Least Concern (Red Data Book 3)

The Sunda Swamp Eel is one of two freshwater eels found in Singapore and arguably one of the most adaptable fishes. It has the ability to breathe air and can also travel short distances on land to search for new water bodies or escape predators (see below). This adaptation allows them to live in a range of freshwater habitats from urban canals to forest streams. Having reduced fins and no scales, it may look like a snake at first glance. This eel can reach to an impressive length of around a meter, making them formidable predators of smaller animals (usually invertebrates and fish) at night.  

In the day, the Sunda Swamp Eel burrows into sediment and under vegetation, but have even been found in mud away from water. They breed by laying eggs in bubble nests similar to some gouramis and bettas.

A juvenile Sunda Swamp Eel found in a concretized drain.

A Sunda Swamp Eel on land attempting to escape a Red-tailed Pipe Snake.

On 10 March 2024, we managed to document the rare predation of a Sunda Swamp Eel by a Red-tailed Pipe Snake (Cylindrophis ruffus). The Sunda Swamp Eel is said to be one of the preferred prey of this semi-fossorial snake and we managed to observe the snake poke around in the mud until the eel sprang out to escape. What followed was a short but slow chase on land before the snake managed to catch up. Catching the eel by its tail, the snake worked its way slowly up the exhausted eel before consuming it whole in under 30 minutes.

This documentation might be the first in-situ sighting of this interspecies interaction but I would like to use this observation to highlight the Sunda Swamp Eel's abilities. As mentioned earlier, they are able to travel short distances on land and it did so to try escaping the snake!

If you would like to read more, check out the Biodiversity Record here!

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.
• Ong JXL, Tay JX, Tan T, Toh WT, Lee L & Lim LT (2024) Biodiversity Record: Predation of swamp-eel by red-tailed pipe snake. Nature in Singapore, 17: e2024044. DOI: 10.26107/NIS-2024-0044

Beardless Barb (Cyclocheilichthys apogon)

Beardless Barb (Cyclocheilichthys apogon)

A Beardless Barb found in a small catchment fed by a forest stream.

Family: Cyprinidae

Species Name: Cyclocheilichthys apogon
Common Name: Beardless Barb, Chemperas, Barbel-less Chemperas
Presence in Singapore: Native
Habitat: Freshwater forest streams, catchments and reservoirs.
Conservation Status: Endangered (Red Data Book 3)

This is an uncommon Barb in Singapore which can be found inhabiting forest streams and catchments in the Central Catchment Nature Reserve, like in MacRitchie Reservoir. This fish can grow up to 25cm in length but are usually found at half the size or less. Interestingly for a barb and as its name suggests, it has no barbels. It forages for small invertebrates on surfaces such as vegetation and along the substrate.

It has a similar look to the introduced Hard-lipped Barb (Osteochilus vittatus) but can be differentiated by having a shorter dorsal fin base in length.

Authors' notes: I need to get a reshoot of this species! 

 

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.

Three Spot Gourami (Trichopodus trichopterus)

Three Spot Gourami (Trichopodus trichopterus)

A Three Spot Gourami found in a freshwater pond at Sungei Buloh Wetland Reserve.

Family: Osphronemidae

Species Name: Trichopodus trichopterus
Common Name: Three Spot Gourami
Presence in Singapore: Native
Habitat: Rural ponds and slow-moving freshwater streams.
Conservation Status: Vulnerable (Red Data Book 3)

The Three Spot Gourami is one popular aquarium fish that is native to Singapore, where it inhabits open countryside waterbodies such as ponds but can also be found in slow-moving forest streams. The colour of this fish is variable, which they come in either powdery blue to almost golden brown. They are named so for the two spots on each side of their bodies, which together with their eyes form the "three spots". These medium-sized fishes can grow up to 15cm and feed on small invertebrates with their small mouths, but might take some plant matter too.

Like all anabantoids, they possess a lung-like organ called the labyrinth organ which allows them to breathe atmospheric air. This trait makes such fishes very hardy as they are usually found in poorly oxygenated waters. Similar to the Croaking Gourami (Trichopsis vittata) and a lot of other Osphronemids, the males build bubble nests it raises the eggs and fry in after breeding.

(All photographs by: Lumin Ong)

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.

Croaking Gourami (Trichopsis vittata)

Croaking Gourami (Trichopsis vittata)

A Croaking Gourami found in a freshwater pond at Sungei Buloh Wetland Reserve. (Photograph by: Lumin Ong)

Family: Osphronemidae

Species Name: Trichopsis vittata
Common Name: Croaking Gourami
Presence in Singapore: Native
Habitat: Rural ponds and slow-moving freshwater streams.
Conservation Status: Least Concern (Red Data Book 3)

The Croaking Gourami is one of two gouramis extant in Singapore and can be recognized by its streamlined, betta-like shape with horizontal stripes. Mature individuals can display a beautiful green-blue body coupled with black or red spots. Growing up to 6 or 7cm, this small fish inhabits open countryside water bodies such as ponds but can also be found in slow-moving freshwater streams in our nature reserves. They feed on small invertebrates and some plant matter if allowed.

Being an anabantoid, they possess a lung-like organ called the labyrinth organ, which allows them to breathe air. This adaptation aids in their versatility when living in poorly-oxygenated waters, which is typical of stagnant water bodies. The males make bubble nests which will be used to raise the eggs and fry after mating.

These gouramis are able to produce a "croaking" sound using their pectoral fins, which they rapidly beat and the swim bladder then helps to amplify the sound caused by their tendons (much like a stringed instrument).

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.

Spanner barb (Striuntius lateristriga)

Spanner barb (Striuntius lateristriga)

A large Spanner Barb found in a small catchment fed by a forest stream.

Family: Cyprinidae

Species Name: Striuntius lateristriga, Barbodes lateristriga (old)
Common Name: Spanner Barb, T-Barb
Presence in Singapore: Native
Habitat: Freshwater forest streams, catchments and quarry lakes.
Conservation Status: Endangered (Red Data Book 3)

A highly recognizable and popular aquarium fish, the Spanner Barb is widespread in Singapore's nature reserves. It can be seen in habitats ranging from small forest streams to wide open quarry lakes. Growing up to 20cm, smaller individuals prefer to school for safety. This fish can easily be identified in Singapore by the side-ways T formed at the side of its body.

Like most barbs, the Spanner Barb is an omnivorous fish that forages near the bottom, where it uses its small barbels to feel for food.

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.

Saddle Barb (Barbodes sellifer)

Saddle Barb (Barbodes sellifer)

A small Saddle Barb found resting at the bottom of a slow-moving forest stream. 

Family: Cyprinidae

Species Name: Barbodes sellifer
Common Name: Saddle Barb
Presence in Singapore: Native
Habitat: Freshwater streams and catchments.
Conservation Status: Vulnerable (Red Data Book 3)

Formerly thought to be Barbodes banksi, it was described as Barbodes sellifer in 2021. The Saddle Barb can grow up to around 14cm and is widespread throughout our nature reserves. It can be found in forest streams, catchments and even some canals in the vicinity of forests.

They are schooling fish and can be found mixing with other fishes like the Elegant Rasbora (Rasbora elegans) as seen on the left. This omnivorous species feed around the bottom by using their short barbels to look for food in the sediment. 

The Saddle Barb can be confused with the similar-looking but introduced Rhombic Barb (Barbodes rhombeus), which has made their way into urban water bodies and some forest streams, potentially displacing or mixing with the native species. The key difference is that the Saddle Barb's patch is much longer and wider than the Rhombic Barb's. 

A small Saddle Barb found in a roadside stream displaying the distinct patch.

The introduced Rhombic Barb displaying separated spots shorter than the Saddle Barb's.

(All photographs by Lumin Ong)

References

• Kottelat, M. and Lim, K.K.P. 2021. Two new species of Barbodes from the Malay Peninsula and comments on 'cryptic species' in the B. binotatus group (Teleostei: Cyprinidae). Retrieved from https://www.researchgate.net/publication/356987794.
• 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.