International Vulture Awareness Day: Vultures in Singapore

(Photo by reurinkjan)

Today is International Vulture Awareness Day, and I thought it would be appropriate to write about records of vultures in Singapore.

But why do we need a day to celebrate vultures? As stated on the International Vulture Awareness Day website:

Vultures are an ecologically vital group of birds that face a range of threats in many areas that they occur. Populations of many species are under pressure and some species are facing extinction.

The International Vulture Awareness Day has grown from Vulture Awareness Days run by the Birds of Prey Programme in South Africa and the Hawk Conservancy Trust in England, who decided to work together and expand the initiative into an international event.

It is now recognised that a co-ordinated international day will publicise the conservation of vultures to a wider audience and highlight the important work being carried out by the world's vulture conservationists.

Sharing Singapore with visiting scientists

Several marine scientists from all over the Asia-Pacific are in town for a workshop on marine biodiversity in the South China Sea. I was able to spend a day helping out with the Raffles Museum of Biodiversity Research (RMBR) as a guide, sharing about Singapore's natural heritage to specialists from the region. (Edit: Mei Lin was a participant as well, and shares more about the workshop in this post)

The King and I: King Cobras in Singapore

(Photo by gerry morgan)

Singapore is home to many species of snake, from tiny burrowing blind snakes less than 20 centimetres long, feeding on soft-bodied invertebrates in the soil, to gigantic pythons more than 5 metres in length, lurking in our drains and sewers in pursuit of rats and even stray cats. While most of our snakes are quite harmless, our forests have their fair share of kraits, coral snakes and pit vipers, with venomous bites that are a genuine cause for concern. The equatorial spitting cobra (Naja sumatrana) is perhaps the most dangerous of our venomous snakes, since it is commonly encountered living near people. Yet these serpents, for all their deadly beauty, pale in comparison to a snake so feared and so iconic that it has become a symbol of the Asian rainforests, a true superstar among the snakes - the king cobra (Ophiophagus hannah).

Raffles Museum Treasures: Giant mudskipper

Giant mudskipper (Periophthalmodon schlosseri)
Collected from Sungei Buloh, December 1994
Native to Singapore

Wild Fact Sheets
A Guide to Common Marine Fishes of Singapore
Guide to the Mangroves of Singapore
Mangrove and wetland wildlife at Sungei Buloh Wetlands Reserve
Ecology Asia
An annotated checklist of the gobioid fishes of Singapore
The mudskipper
FishBase
The giant mudskipper Periophthalmodon schlosseri facilitates active NH4+ excretion by increasing acid excretion and decreasing NH3 permeability in the skin


(Photo by NatureInYourBackyard)

Wow! An insect that looks like a man’s face

A STOMPer spotted this strange looking insect at Sungei Buloh Wetland Reserve and says the back of the insect looks like a man's face.

In an email to STOMP today (Feb 28), the STOMPer says:

"The other day when I was visiting the Sungei Buloh Wetland Reserve I came across this strange insect on the branch of a mangrove tree.

"It has a pair of antennae and six orange legs.

"The back of the insect looks like a man's face with two eyes and a long beard protruding from the chin.

"Could someone please tell me what insect this is?"

Related posts: Does anyone know what this strange insect is? (30th December 2009)
Strange insect with face on its back (21st October 2009)

As far as I know, this appears to be a species of shield bug (Pentatomoidea), although my knowledge of insect taxonomy does not allow me to make a more definite identification.

Barnacles are hermaphrodites, i.e. both male and female, and other Sungei Buloh tales

A STOMPer shares his knowledge of these marine creatures which he came across when he was at Sungei Buloh Nature Park.

In an email to STOMP, Marine Biologist says:

"These pictures were taken at the shore of Sungei Buloh Nature Park.

"The mangrove swamp is a place teeming with small marine animals of various shapes and sizes.

"The common nerite (Nerita lineata) is a mangrove snail and it grazes on algae at night during low tide.

"Its hard operculum is used for defense purposes.

"At low tide, the nerite remains on the tree trunk exposed to the air.

"The signaller crab has orange claws and feeds on worms.

"This common periwinkle is conical in shape and lives on the trunks of mangrove trees, grazing on algae.

"It is well adapted to terrestrial life.

"Barnacles are marine and tend to live in tidal waters.

"They grow on any hard surface immersed in seawater, so they are found everywhere in the intertidal zone.

"They are found on rocks, trees, pillars and boats.

"Barnacles are crustacean-like crabs.

"They are hermaphrodites, each barnacle having both male and female reproductive organs."

I find it mildly annoying that despite the title, the main image for this post doesn't even feature barnacles at all.

The correct name for the lined nerite is a little confusing. For many years, it was known as Nerita lineata, although recently, it appears that Nerita articulata is the proper name. To make matters worse, this species is also commonly known as Nerita balteata.

I believe that the crab in the photo is indeed the orange signaller crab (Metaplax elegans), while the periwinkle is likely to be the black-mouthed mangrove periwinkle ( Littoraria melanostoma).

To be pedantic, barnacles aren't "crustacean-like crabs", which is nonsensical, since crabs are crustaceans in the first place, and besides, barnacles aren't crabs. I'm sure the writer meant to say that they were "crustaceans - like crabs".

And he left out what is in my honest opinion, the most interesting fact about barnacles: they are extraordinarily well hung. A barnacle may possess a penis about 10 times its body length.

I guess this would be a good time to introduce this quirky and yet very educational video on barnacles:

The sights of Sungei Buloh Nature Reserve

STOMPer Nature Lover shares with STOMPers the beautiful sights of Sungei Buloh Nature Reserve.

Says this STOMPer:

"In picture one, it shows the entrance to the male and female toilets. You can see a male bird and a female bird to indicate which side you are to turn.

"In picture two, this long bridge crosses the Sungei Buloh Besar. The wooden bridge is supported by concrete pillars as the current here is very strong.

"In picture three, this fish sculpture is found at the entrance.

"In picture four, the lake beside the cafe teems with fish, tortoises and monitor lizards.

"In picture five, the tortoise swims in the water and occasionally it comes to the shore to bask in the sun."

I really wonder why this particular person often seems to post about things that frankly don't seem particularly interesting or noteworthy. There's so much to see at Sungei Buloh Wetland Reserve, that I'm really puzzled as to why he even found the toilet signs and the bridge so fascinating in the first place.

And once again, he makes the annoying mistake of calling a red-eared slider (Trachemys scripta elegans) a tortoise. It really annoys me, especially when he had previously posted about the differences between tortoises and turtles.

Migration

Waders at Sungei Buloh Wetland Reserve;
(Photo by chia_alfred)

That many species of birds migrate is a fact known to most of us. But we often forget about the struggles and threats faced by many migratory birds. Habitat loss at every stage of their journey, from breeding and wintering grounds, to critical stopover and staging areas for birds to refuel and take refuge from bad weather along the way, is a great threat to most migratory bird species. Deliberate hunting and trapping is another severe challenge, especially at key points where entire flocks are funneled into a small area due to geography. Agriculture intensification, pesticide use, urban expansion, power lines, and the proliferation of wind energy and high-rise buildings can also exact a severe toll on some of the world's great travellers.

This inspiring and moving video by the Born To Travel campaign shows the amazing annual voyage undertaken by some birds, and illustrating the seemingly insurmountable challenges they face at every stage of their epic journey. That some of these birds travel great distances across entire continents, and over mountains, deserts and oceans, is simply stunning and awe-inspiring.



Although the Born To Travel campaign appears to focus on birds that utilise the African-Eurasian Flyway, it is important to note that similar migrations are to be found in other continents. For example, there are birds that travel from Canada to Argentina and back, making the trip across the Gulf of Mexico, while others travel between the Russian Arctic and India, crossing the deserts of central Asia and the Himalayas.

Singapore itself is a vital stopover for many waterbird species using the East Asian-Australasian Flyway. For much of the year, residents in our forests and wetlands are joined by a retinue of visitors from distant lands. For many birds, the loss of a single feeding and resting site can make the difference between surviving to carry on the next leg of the journey, and perishing from exhaustion.


Waders at Sungei Buloh Wetland Reserve.
Left: Whimbrel (Numenius phaeopus);
Right: Mongolian plover (Charadrius mongolus);
(Photos by kampang)

There are many books available on bird migration; recent titles include Atlas of Bird Migration, Living on the Wind, How Birds Migrate, and Bird Migration. I haven't read any of these titles myself, but I have read Silence of the Songbirds and No Way Home, which devote a fair bit of space to discussing the decline of migratory bird species.

To end off, here's a couple of trailers from a most excellent movie that is all about bird migration. Le Peuple Migrateur, also known as Winged Migration, is a 2001 film that captures the journeys of birds in amazing detail.





May these journeys continue to amaze and inspire us for generations to come.

(Hat-tip to GrrlScientist)

Non-eels

Which one is the eel?

So far, we have looked at a wide variety of eels, from moray eels (F. Muraenidae), to snake eels (F. Ophichthidae), from conger eels (F. Congridae) and pike conger eels (F. Muraenesocidae), to the freshwater eels (F. Anguillidae). We've even spent a bit of time on 2 very little-known eel families, the spaghetti eels (F. Moringuidae) and false moray eels (F. Chlopsidae)

All the families I've talked about belong to the true eels, or Anguilliformes. In truth, there are numerous other eel-like fishes that are also known as eels, but which are not closely related to the true eels.

On our shore trips, we often encounter a long, eel-like fish. This is the carpet eel blenny (Congrogadus subducens), a predatory species commonly found in reefs, coral rubble and seagrass areas.


Carpet eel blenny, Pulau Sekudu;
(Photo by Ria)

However, the carpet eel blenny is not actually related to eels, and instead belongs to a family known as dottybacks (F. Pseudochromidae).

Other fishes on our shores which might get confused with eels include pipefish (F. Syngnathidae) and eel-tailed catfish (F. Plotosidae). However, it is easy to tell them apart from eels; pipefish have the characteristic long tubular snout, while catfish can be recognised by their barbels.


Left: ?Tidepool pipefish (Micrognathus micronotopterus), Changi;
Right: Black eel-tail catfish (Plotosus canius), Changi;
(Photos by Ria)

More rarely seen are sand-divers (F. Trichonotidae); we have not been able to identify the species encountered on the Sisters Islands.


Blue-spotted sand diver (Trichonotus setiger), Kenting;
(Photo by divingintaiwan)

Blennies (F. Blenniidae) often tend to be somewhat elongated, but the snake eel blenny (Xiphasia setifer) is the most eel-like of the family.


Snake eel blenny, Nelson Bay;
(Photo by Dave Harasti)

The cutlassfishes (F. Trichiuridae) are also quite eel-like in appearance, with the largehead hairtail (Trichiurus lepturus) being 1 of the species known to occur in our waters.


Largehead hairtail;
(Photo by Don Flescher)

In temperate waters, more eel-like fish reside. Among them are the gunnels (F. Pholidae), eelpouts (F. Zoarcidae), pricklebacks (F. Stichaeidae), wolf eels (F. Anarhichadidae), and sand lances or sand eels (F. Ammodytidae). Despite the fact that some of their common names have something to do with eels, all these fish are not closely related to eels at all.




Top: Rock gunnel (Pholis gunnellus), Zeeland;
(Photo by Arne Kuilman)
Centre left: Eelpout (Zoarces viviparus), Ona;
(Photo by andyolsson)
Centre right: Snake blenny (Lumpenus lampretaeformis), Norway;
(Photo by Erling Svensen)
Lower left: Wolf eel (Anarrhichthys ocellatus), Vancouver Island;
(Photo by Dan Hershman)
Lower right: Small sand eel (Ammodytes tobianus), Loch Torridon;
(Photo by Trevor Meyer)

The eelpouts are predominantly fish of the ocean depths, where a wide variety of elongated, serpentine fish can be found. These include the cuskeels (F. Ophidiidae), halosaurs (F. Halosauridae), deep-sea spiny eels (F. Notacanthidae), dragonfishes (F. Stomiidae), grenadiers (F. Macrouridae), bobtail snipe eels (F. Cyematidae), pelican eel (F. Eurypharyngidae), onejaws (F. Monognathidae), gulper eels (F. Saccopharyngidae), ribbonfish (F. Trachipteridae), and oarfish (F. Regalecidae). There is even a deep sea shark that looks like an eel, the frilled shark (Chlamydoselachus anguineus), which is the sole representative of its family (F. Chlamydoselachidae).

As we have seen in previous posts, several species of eel will enter freshwater. To make things more confusing, there is an unrelated family of freshwater fish known as swamp eels (F. Synbranchidae), found in tropical South and Central America, West Africa, Asia and Australia. The most well-known species is the Asian swamp eel (Monopterus albus), found throughout Asia. This species is commonly eaten, and is widespread in aquaculture; in fact, I believe that Singaporeans are generally more familiar with this species than with any of the true eels.


Asian swamp eels at Khai Seng Trading & Fish Farm, Kranji;

The spiny eels (F. Mastacembelidae) are another family of eel-like fish with representatives in South-east Asia. Native to Africa and Asia, many species can be found in the aquarium trade. Spiny eels get their name from the row of short spines on the back, in front of their dorsal fins. However, the most obvious distinguishing feature is the long fleshy appendage on the tip of the snout, which gives the spiny eel a comical appearance.


2 large species of spiny eel commonly seen in the aquarium trade.
Left: Tyre-track eel (Mastacembelus armatus);
Right: Fire eel (Mastacembelus erythrotaenia);
(Photos by cyprinoid)

Among the loaches (F. Cobitidae) of Eurasia, some species are elongated and can also bear some superficial resemblance to eels. The well-developed fins and the short barbels around the mouth should help to distinguish loaches from eels.


Left: Giant kuhli loach (Pangio myersi);
(Photo by cyprinoid)
Right: Eel loach (Pangio anguillaris);
(Photo by nttrbx)

A large fish that is commonly confused with the true eels is the electric eel (Electrophorus electricus) of South America. However, it is not an eel, and instead is a highly specialised South American knifefish.


Electric eel at Adventure Aquarium, New Jersey;
(Photo by Floater Ya-Ya)

The South American knifefishes or Gymnotiformes are freshwater species of tropical South and Central America. They generally have elongated bodies, and in fact, are are able to give off a weak electric current to help them navigate in murky waters, as well as to communicate with one another. The electric eel has gone a step further and uses electrical discharges to stun prey and defend itself. Despite their often eel-like appearance, these fish propel themselves by undulations of the long anal fin, and so do not swim like eels. The electric eel belongs to the gymnotids, or naked-back knifefishes (F. Gymnotidae), while another familiar species in aquaria, the black ghost knifefish (Apteronotus albifrons), is a member of the ghost knifefish family (F. Apteronotidae). The remaining South American knifefish families are the bluntnose knifefishes (F. Hypopomidae), sand knifefishes (F. Rhamphichthyidae), and glass knifefishes (F. Sternopygidae).




An assortment of South American knifefish.
Top left: Black ghost knifefish;
(Photo by Neil Hepworth)
Top right: Electric eel;
(Photo by brian.gratwicke)
Centre left: Banded knifefish (Gymnotus carapo);
Centre right: Bluntnose knifefish (Brachyhypopomus occidentalis);
(Photo by Miguel Landines)
Bottom left: Trumpet knifefish (Rhamphichthys rostratus);
(Photo by Ricky Mensch)
Bottom right: Glass knifefish (Eigenmannia virescens);
(Photo by Mauricio Camargo)

The featherbacks or knifefishes (F. Notopteridae) of Africa and tropical Asia are superficially similar to the South American knifefishes, but are unrelated, and lack the ability to generate electricity.


2 species of knifefish found in the aquarium trade.
Left: Clown knifefish (Chitala ornata);
(Photo by Lai Sektong)
Right: African knifefish (Xenomystus nigri);

In a bizarre example of convergent evolution, another large eel-like fish has evolved the ability to generate electricity. This is the aba (Gymnarchus niloticus), also known as the Nile knifefish. The sole member of its family (F. Gymnarchidae), the aba, a fish that is found in many African river systems, is unrelated to the South American knifefishes, but also uses a weak electrical current to navigate. Interestingly enough, in this species, it is the dorsal fin that is the main source for propulsion.


Aba;

Other African fish that can from time to time be mistaken for eels include several species of walking catfish (F. Clariidae), such as the eel catfish (Channallabes apus) and flat-head eel catfish (Gymnallabes typus). Once again, the long barbels give them away.


Left: Eel catfish;
(Photo by Benjamin Lee)
Right: Flat-head eel catfish;
(Photo by Christian Hauzar)

Two families of catfishes (F. Trichomycteridae, F. Heptapteridae) of South America have several species that are eel-like. These include species with bizarre habits, such as the infamous parasitic candiru (Vandellia cirrhosa), and the subterranean cistern catfish (Phreatobius cisternarum).


Left: Candiru;
(Photo by dylanellis30)
Right: Cistern catfish;
(Photo by Janice Muriel-Cunha)

The bichirs (F. Polypteridae) are an exclusively African family of fish that do appear eel-like in terms of appearance and habits. Predatory in nature, with long sinuous bodies, it is difficult not to draw comparisons between bichirs and freshwater eels. The elongation of the body is taken to extremes in the reedfish (Erpetoichthys calabaricus).


Left: Senegal bichir (Polypterus senegalus);
Right: Reedfish;

Befitting their prehistoric appearance, bichirs are actually among the most primitive bony fish alive today. Another family of eel-like African fish also has an ancient heritage; these are the African lungfish (F. Protopteridae). The South American lungfish (Lepidosiren paradoxa), the sole member of its family (F. Lepidosirenidae), also looks like an eel.


Left: West African lungfish (Protopterus annectens);
Right: South American lungfish;
(Photos by SRD)

Even some of the most primitive 'fish' (to use the term very loosely) are eel-like. The parasitic lampreys (F. Petromyzontidae) and scavenging hagfish (F. Myxinidae) lack jaws, and while the lamprey are included among the vertebrates, hagfish are not even considered true vertebrates; they have skulls of cartilage but lack a vertebral column.


Left: Sea lamprey (Petromyzon marinus);
Right: Atlantic hagfish (Myxine glutinosa);
(Photos by Anders Salesjö)

As if having such a great variety of eel-like fishes was not enough, there are amphibians which are also eel-like. Thankfully, there aren't any eel-like frogs; it is the caecilians and salamanders which have evolved eel-like species. The typhlonectines are a subfamily of caecilians (F. Caecilidae) which are fully aquatic, although they still breathe air. To make matters worse, they are commonly mislabeled in the pet trade as 'rubber eels'.


Rio Cauca caecilian (Typhlonectes natans);
(Photo by brian.gratwicke)

Among the salamanders, the sirens (F. Sirenidae), not to be confused with the mammals known as sea cows or sirenians, are somewhat eel-like, but have external gills and a pair of small forelimbs. The olm (Proteus anguinus) is the most eel-like member of the mudpuppy family (F. Proteidae), but can be obviously differentiated from eels by its lack of pigmentation and eyes, and the presence of bushy external gills and 4 small but well-developed legs. It is the amphiumas (F. Amphiumidae), with their elongated bodies and minuscule legs, that are most easily confused with eels. Amphiumas are sometimes known as Congo eels, although they are not eels, and don't live anywhere near the Congo Basin in Africa.



4 eel-like amphibians.
Upper left: Cayenne caecilian (Typhlonectes compressicauda);
(Photo by Danté Fenolio)
Upper right: Lesser siren (Siren intermedia);
(Photo by Pierson Hill)
Lower left: Olm;
(Photo by Nick Baker)
Lower right: Two-toed amphiuma (Amphiuma means);
(Photo by Pierson Hill)

Finally, it goes without saying that on occasion, a snake swimming in the water might be mistaken for an eel. Many snakes found in the region, such as the file snakes (F. Acrochordidae), mock vipers (F. Natricidae), water snakes (F. Homalopsidae), and sea kraits and sea snakes (F. Elapidae), are closely associated with aquatic and marine environments.




6 local species of snake which are closely associated with water.
Top left: Banded file snake (Acrochordus granulatus), Chek Jawa;
(Photo by Ria)
Top right: Painted mock viper (Psammodynastes pictus), Borneo;
(Photo by dennisikon)
Centre left: Puff-faced water snake (Homalopsis buccata), Nee Soon;
(Photo by Siyang)
Centre left: Dog-faced water snake (Cerberus rynchops), Sungei Buloh;
(Photo by Ria)
Bottom left: Yellow-lipped sea krait (Laticauda colubrina), Pulau Hantu;
(Photo by Ria)
Bottom right: Marbled sea snake (Aipysurus eydouxii), Chek Jawa;
(Photo by Ng Bee Choo)

Oh, and do you remember the 2 fish at the top of this post? Which one is the eel? Well, here's the answer...


Brown-spotted moray (Gymnothorax reevesii), Beting Bronok;
(Photo by Chee Kong)


Carpet eel blenny, Sentosa;

And with that, I've come to the end of my eel series.

Part 1: Moray eels (Muraenidae)
Part 2: Snake eels (Ophichthidae)
Part 3: Conger eels (Congridae) and Pike conger eels (Muraenesocidae)
Part 4: Freshwater eels (Anguillidae)
Part 5: Spaghetti eels (Moringuidae) and false moray eels (Chlopsidae)
Part 6: Non-eels (this post)