Elongate Mudskipper (Pseudapocryptes elongatus)

Elongate Mudskipper (Pseudapocryptes elongatus)

An adult Elongate Mudskipper found in a back mangrove creek.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Pseudapocryptes elongatus
Common Name(s): Elongate Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Mangrove forest creeks down to mudflats.
Conservation status: Vulnerable (Red Data Book 3)

This is one of the lesser encountered mudskipper species in Singapore. This is a long species as evident by its common name, reaching up to a maximum length of 24cm. The Elongate Mudskipper has well-proportioned fins which aren't flashy like its relatives. Both juveniles and adults have varying levels of slanted stripes on a greenish-brown/grey body. While they have been recorded living down in the mudflats, sightings of them in Singapore seem to be limited to back mangrove creeks such as in Pulau Ubin, where they're most often seen. In 2024, juveniles of the Elongate Mudskipper were found to be living in the open breakwater of Marina East by us, where they have burrows in the muddy pools present. With adults being sighted before in the same area, it is a surprising habitat considering their preferences but they seem to be thriving.

Elongate Mudskippers are omnivorous, feeding on algae and small invertebrates such as worms. As mentioned in (Polgar, 2013), they have a few feeding styles such as sifting (like the Bearded Mudskipper), scraping (like the Boddart's Blue-spotted Mudskipper) and pump-suspension feeding where they inhale suspended particles. This species is the most aquatic of all mudskippers seen reliably in Singapore, preferring to sit under water with only its eyes breaching the surface. 

A juvenile Elongate Mudskipper from Marina East. (Photograph by: Jiayuan Lin)

A juvenile Elongate Mudskipper which without Jiayuan's side shot, it might've been impossible to ID.

Check out this video: https://www.youtube.com/watch?v=SfArKeBzsVE&ab_channel=SGfishesabovewater



References

• FishBase. Pseudapocryptes elongatus Cuvier, 1816 – (Mudskipper). Retrieved from https://fishbase.se/summary/Pseudapocryptes-elongatus
• 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, Tay JX & JY Lin (2025) Biodiversity Record: Elongate mudskippers, Pseudapocryptes elongatus, at Marina East. Nature in Singapore, 18: e2025010. DOI: 10.26107/NIS-2025-0010
• Polgar, G. Gobiidae: Oxudercinae – Pseudapocryptes elongatus Cuvier, 1816. Retrieved from http://www.mudskipper.it/SpeciesPages/elon.html 

Bearded Mudskipper (Scartelaos histophorus)

Bearded Mudskipper (Scartelaos histophorus)

A mated pair of Bearded Mudskippers.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Scartelaos histophorus
Common Name(s): Bearded Mudskipper, Walking Goby

Presence in Singapore: Native
Habitat: Coastal: Open mudflats and creek banks.
Conservation status: Vulnerable (Red Data Book 3)

One of Singapore's lesser encountered mudskippers due to its habitat preference. The Bearded Mudskipper is easily recognized by its elongated body shape which can reach up to 14cm in length. It is overall grey with sparse black dots. The first dorsal fin is very tall and it is raised in territorial displays as with all mudskippers. The unique feature about this species is that it has barbels below its head, resulting in the common name.

The Bearded Mudskipper is mostly encountered on open mudflats where the mud is sticky and one can sink in it to varying levels. They can also be encountered further upstream along creek banks but larger individuals are further out to sea. Similar to the Boddart's Blue-spotted Mudskipper, they only appear during low tide and hide in their burrows where there is an air pocket during high tide. This species is omnivorous and it feeds by sifting through the mud, running it through its gills and expelling the sediment. It feeds on tiny organisms such as algae, crustaceans and worms.

They are known for their impressive displays where the male leaps into the air but keeps its tail on the ground, making it seem like it is standing up! If a female is interested, they share a burrow together. It appears that juveniles are not as elongated and have the normal mudskipper proportions.

A Bearded Mudskipper sifting through the mud for food.

A small Bearded Mudskipper that has just emerged from its burrow.

YouTube videos

• Passive behaviour: https://www.youtube.com/watch?v=BWEUVAqJFzw&ab_channel=SGfishesabovewater
• Burrow emergence: https://www.youtube.com/watch?v=9MdIDaMvDUs&ab_channel=SGfishesabovewater

References

• FishBase. Scartelaos histophorus Valenciennes, 1837 – (Walking goby). Retrieved from https://www.fishbase.se/summary/Scartelaos-histophorus.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.

Boddart's Blue-spotted Mudskipper (Boleophthalmus boddarti)

Boddart's Blue-spotted Mudskipper (Boleophthalmus boddarti)

A small Boddart's Blue-spotted Mudskipper found in Sungei Buloh Wetland Reserve.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Boleophthalmus boddarti
Common Name(s): Boddart's Blue-spotted Mudskipper, Boddart's Goggle-eyed Goby, Blue-spotted Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Open mudflats near and beyond the mangrove roots.
Conservation status: Vulnerable (Red Data Book 3)

This genus of large mudskippers are unmistakable for they are commonly filmed for documentaries due to their range of behaviours. The Boddart's Blue-spotted Mudskipper can reach a maximum recorded length of 22cm and can be separated from other blue-spotted mudskippers via its slanting black stripes. As its name suggests, both the sides of the body and fins are covered in blue spots. Their dorsal fins are impressive with long, filamentous spines.

The Boddart's Blue-spotted Mudskipper lives out on the open mudflats that are revealed during low tide beyond the mangrove trees. Larger individuals are found further out than smaller individuals, which reside closer to the trees. During high tide, this species hide in their burrows where there is an air pocket inside. 

This mudskipper has a stocky build which it smoothly drags across the mudflats it calls home. Its large mouth appears to be more for burrowing and fighting rather than capturing prey, for it leads a herbivorous and detritivorous lifestyle. To feed, they skim the mud by moving their heads side to side, scraping up the microbes present on the surface such as algae.

Males put on a beautiful display by jumping into the air with fins fully flared, in hopes of attracting a female. If a female is interested, they enter the burrow together to mate. Very small juveniles are pinkish (see Ong & Tay, 2024). 

Mudskippers roll on their sides to keep themselves moist!

A juvenile Boddart's Blue-spotted Mudskipper.

References

• FishBase. Boleophthalmus boddarti (Pallas, 1770) – (Boddart's goggle-eyed goby). Retrieved from https://fishbase.se/summary/4901
• 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 & 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

Dusky-gilled Mudskipper (Periophthalmus variabilis)

Dusky-gilled Mudskipper (Periophthalmus variabilis)

A small Dusky-gilled Mudskipper on the sandy shores of St John's Island.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmus variabilis
Common Name(s): Dusky-gilled Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Mangrove forests down to lower intertidal zones.
Conservation status: Vulnerable (Red Data Book 3)

The Dusky-gilled Mudskipper is a small species, reaching a maximum total length of 7cm. This species is identified by its variable black blotches that usually fade towards the bottom. It also has tiny whitish-blue spots across the body. Its red dorsal fins are similar to the Silver-lined Mudskipper but in the first dorsal fin, the black margin curves down to the base and it lacks the many white specks. 

The Dusky-gilled Mudskipper was formerly synonymized with Periophthalmus novemradiatus, leading to some outdated signboards in our parks. It is now a recognized separate species from its relative further north. 

This species shares a similar habitat range to most of its relatives, being abundant in back mangroves all the way down to intertidal zones. It doesn't seem to stray far from the shelter of mangroves however unlike the Gold-spotted Mudskipper. It is an opportunistic carnivore that feeds on small invertebrates.

Territorial display of a Dusky-gilled Mudskipper with dorsal fins in full view.

References

• FishBase. Periophthalmus variabilis Eggert, 1935 – (mudskipper). Retrieved from https://fishbase.se/summary/65362
• 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.

Slender Mudskipper (Periophthalmus gracilis)

 Slender Mudskipper (Periophthalmus gracilis)

A Slender Mudskipper seen on the sandy shores of St John's Island.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmus gracilis
Common Name(s): Slender Mudskipper, Graceful Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Mangrove forests down to lower intertidal zones.
Conservation status: Vulnerable (Red Data Book 3)

The Slender Mudskipper is a small species, reaching a maximum recorded length of 4.5cm. This species usually has thin, silver stripes and slanting black bands on the side of its body, making it easy to confuse with the Silver-lined Mudskipper and Dusky-gilled Mudskipper. The best way to identify this mudskipper is to look at the gap between its two dorsal fins, which are very far part compared to its relatives. The first dorsal fin is also small and rectangular, with dark patterns and blue margins over a lighter colour base compared to the red base of the two earlier mentioned species.

This is a common species, being seen in the back mangroves down to open intertidal zones such as mudflats. It is often seen alongside its relatives listed in this blog as well. Being an opportunistic carnivore, it preys on small invertebrates. 

A Slender Mudskipper caught via hand-line for dorsal fin inspection. (Photograph by: Jiayuan Lin)

References

• FishBase. Periophthalmus gracilis Eggert, 1935 – Graceful (Slender) Mudskipper. Retrieved from https://www.fishbase.se/summary/Periophthalmus-gracilis
• 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.

Gold-spotted Mudskipper (Periophthalmus chrysospilos)

Gold-spotted Mudskipper (Periophthalmus chrysospilos)

A male Gold-spotted Mudskipper identified by the elongated first spine of the first dorsal fin. This was seen in the intertidal zone of Bukit Chermin Boardwalk.

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmus chrysospilos
Common Name(s): Gold-spotted Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Intertidal zones such as sandy beaches and mudflats
Conservation status: Vulnerable (Red Data Book 3)

The Gold-spotted Mudskipper is an average-sized species, reaching around 10cm long usually. This species is easily identified by the orange-gold spots that cover the sides of its body, resulting in its common name. It also has bright orange dorsal fins that stand out from the other mudskippers in Singapore. In the males, the first dorsal spine is very elongated, which is a feature not seen in its relatives under the same genus locally.

The Gold-spotted Mudskipper is abundant in open intertidal zones along the coast such as mudflats and sandy beaches. It is rarely seen inside mangrove forests where its relatives are common. During high tide, they go further up the beach or wait it out on mangrove roots and other elevated surfaces.

A Gold-spotted Mudskipper braving the high tide and strong winds while clinging to a mangrove sapling.

This species is omnivorous and appears to have different feeding styles. It hunts smaller invertebrates on-sight but also grazes on surfaces for algae and microorganisms. We have observed this species grazing on the rocks they're sitting on every time the wave crashes into it.

Territorial display of the Gold-spotted Mudskipper.

References

• FishBase. Periophthalmus chrysospilos Bleeker, 1853 – Gold-spotted Mudskipper. Retrieved from https://www.fishbase.se/summary/Periophthalmus-chrysospilos.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.

Silver-lined Mudskipper (Periophthalmus argentilineatus)

Silver-lined Mudskipper (Periophthalmus argentilineatus)

A Silverlined Mudskipper seen on St John's Island, where it is rather plentiful. 

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmus argentilineatus
Common Name(s): Silver-lined Mudskipper, Barred Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Mangrove forests down to lower intertidal zones.
Conservation status: Vulnerable (Red Data Book 3)

This is an abundant species seen in Singapore from both inside mangrove forests to even sandy shores that at least meet a patch of mangroves (indicating some mud). The Silver-lined Mudskipper is an average-sized mudskipper, reaching just under 10cm at max. It is named after the silver stripes on the sides of its body but other species can have similar patterns as well. Thus, a shot of the raised dorsal fins can help separate it from similar-looking species in the region. The first dorsal fin is red with a black and white margin running from the top to the back of the fin, while the red area has many spots. 

A Silver-lined Mudskipper flaring its dorsal fins to another of its kind. (Photograph by: Lumin Ong)

This species is an opportunistic carnivore, feeding on whatever could feed in its mouth such as small invertebrates.

A Silver-lined Mudskipper feeding on what appears to be a polychaete worm that it dug out from the mud.

Although not recorded in Singapore (so far), Periophthalmus kalolo frequently appears alongside this species elsewhere and look pretty much the same. A ventral view of the pelvic fin is currently the best way to differentiate them (Polgar, 2014). 

References

• Polgar, G. Gobiidae: Oxudercinae – Periophthalmus argentilineatus Valenciennes, 1837. Retrieved from http://www.mudskipper.it/SpeciesPages/arge.html
• FishBase. Periophthalmus argentilineatus (Valenciennes, 1837) – Barred Mudskipper. Retrieved from https://www.fishbase.se/summary/Periophthalmus-argentilineatus
• 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.

Yellow-spotted Mudskipper (Periophthalmus walailakae)

Yellow-spotted Mudskipper (Periophthalmus walailakae)

A Yellowspotted Mudskipper seen in Berlayer Creek. (Photograph by: Lumin Ong)

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmus walailakae
Common Name(s): Yellow-spotted Mudskipper, Walailak's Mudskipper

Presence in Singapore: Native
Habitat: Coastal: Mangrove forests
Conservation status: Vulnerable (Red Data Book 3)

This is a large mudskipper species for its genus, reaching nearly 13cm in length at max. It is relatively common in our muddy mangrove forests but can also be seen further out along the shore, sometimes in sandier habitats. The top half of its body has several saddle-like stripes while its flanks are covered with yellow spots, giving it the common name it's known by locally. Its first dorsal fin is un-patterned, being red with black and white margins along the top down to the back. 

The Yellow-spotted Mudskipper is an opportunistic carnivore, preying on small crustaceans and other invertebrates. Its burrows are usually further back in the mangroves in mud and it doesn't seem to stray far from the shelter of the mangrove forests.

A Yellow-spotted Mudskipper showing a bit of its first dorsal fin. (Photograph by: Lumin Ong)

References

• FishBase. Periophthalmus walailakae. Country species summary for Singapore. Retrieved from https://www.fishbase.se/Country/CountrySpeciesSummary.php?c_code=764&id=61443
• Polgar, G. Gobiidae: Oxudercinae – Periophthalmus walailakae Darumas & Tantichodok, 2002. Retrieved from http://www.mudskipper.it/SpeciesPages/wala.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.

Giant Mudskipper (Periophthalmodon schlosseri)

Giant Mudskipper (Periophthalmodon schlosseri)

A Giant Mudskipper emerging from its burrow in Pasir Ris Park's mangroves. (Photograph by: Lumin Ong)

Family: Oxudercidae (Subfamily Oxudercinae - Mudskippers)

Species Name: Periophthalmodon schlosseri
Common Name(s): Giant Mudskipper

Presence in Singapore: Native
Habitat: Coastal: muddy mangrove swamps and mudflats.
Conservation status: Least Concern (Red Data Book 3)

This is the largest mudskipper seen in Singapore and one of the largest in the entire world for it can reach almost 30cm in length. Due to its sheer size and abundance in the right habitats, it is also the most often seen mudskipper in Singapore as it is hard to miss. It is easily recognizable via a dark, horizontal stripe that runs along the sides of its body starting from the eyes. It is also peppered with light blue spots towards the bottom half of its body.

The Giant Mudskipper is carnivorous, possessing impressive fangs for its kind. It preys on smaller fishes, crustaceans and have even been known to eat reptiles such as snakes. They have been observed digging for burrowing prey such as eels. This highly territorial species chases other individuals that get too close.

The Giant Mudskipper inhabits mangrove swamps where the substrate is muddy and can even be found further out on open mudflats. They dig large burrows marked by a round pool visible at low tide, where the mudskipper usually sits in. In mated pairs, both the male and female help to maintain the burrow These pools are usually shelter to smaller mangrove fishes such as their goby cousins during low tide (see Ong & Tay, 2024), which are often too small for the mudskipper to bother about. They can be seen waiting out the high tide on mangrove roots and other elevated surfaces. 

A Giant Mudskipper hard at work digging in Sungei Buloh Wetland Reserve. (Photograph by: Lumin Ong)

A young Giant Mudskipper taking shelter on a rock during high tide. (Photograph by: Lumin Ong)

References

• FishBase. Periophthalmodon schlosseri (Pallas, 1770) – Giant Mudskipper. Retrieved from https://www.fishbase.se/summary/Periophthalmodon-schlosseri
• 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 & 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