Atyid shrimps of Singapore

[Trichopsis]

I managed to find this old paper from December 1961 , that lists the many shrimp and prawn species, both marine and freshwater, recorded to occur in Singapore at that time.

Johnson, D.S. 1961. A Synopsis of the Decapoda Caridea and Stenopodidea of Singapore, with notes on their distribution and a key to the genera of Caridea occurring in Malayan waters. Bulletin of the National Museum, Singapore 30:44-79. [link to PDF]

Here's what it says about the Atyidae of Singapore:

Atyidae

The Atyidae are poorly represented in Singapore freshwaters, though abundant in low-salinity brackish waters.

• Caridina gracilirostris De Man, 1892

In Singapore island this species is confined to low-salinity and, more rarely, high-salinity brackish waters and to adjoining freshwaters which are subject to tidal influence. In such localities it may be very numerous, though seldom abundant.

• Caridina brachydactyla peninsularis Kemp, 1918

This species is not common in Singapore. I have collected it at Sungai Seletar in low-salinity brackish water and in freshwater subject to tidal influence. I have also
found it in a freshwater stream just above the tidal area near Jurong village. There are specimens in the Bedford-Lanchester collection from Tanglin; but the species has not been found in that part of Singapore in recent years and may have been exterminated there by the increasing urbanization of Tanglin.

I have previously (Johnson, 1961) accepted the view of Bouvier (1925) that C.
brachydactyla is a synonym of C. nilotica P. Roux. I now think that it is a valid species (Johnson, 1960a). Singapore specimens, as well as all others which I have seen from Malaya, agree in all essential features with Kemp's types from Penang and I consider that peninsularis Kemp is a valid subspecies of C. brachydactyla.

• Caridina propinqua De Man, 1908

C. propinqua is the most abundant member of its family in Singapore. It inhabits low-salinity brackish waters and adjoining fresh waters which are subject to tidal influence. It is often abundant in such habitats, and occurs everywhere in the island where they are found. Elsewhere C. propinqua, though essentially a brackish water form, is sometimes found in freshwaters which are not connected with the sea. It ranges from Lake Chilka through to Thailand and Malaya. Singapore is its most southerly known locality.

• Caridina tonkinensis Bouvier, 1919

Like the preceeding species, C. tonkinensis characteristically inhabits low-salinity
brackish waters. It is apparently somewhat rarer than C. propinqua and in Singapore it has so far only been found in the north-eastern portion of the island. I have collected in a number of similar localities in western Malaya. Until its recent discovery in Malaya (Johnson, 1961), C. tonkinensis was only known from the type-specimens collected by Sollaud at Tonkin.

• Caridina weberi sumatrensis De Man, 1892

C. weberi sumatrensis is apparently rather rare in Malaya, though widely distributed. I have collected a single specimen from a shaded stretch of the Sungai Seletar, below the Nee Soon swamp forest, but above the tidal zone. It does not appear to extend into either the swamp forest or the tidal zone.

Note that this article precedes the description of Caridina temasek Choy & Ng, 1991.
Choy, S.C. & Ng, P.K.L. 1991. A new species of freshwater atyid shrimp, Caridina temasek (Decapoda: Caridea: Atyidae) from Singapore. Raffles Bulletin of Zoology 39:265-277. [link to PDF]

A more recent article was published in 2007 by Cai Yixiong, Peter Ng, and Satish Choy.

Cai, Y., Ng, P.K.L and Choy, S. 2007. Freshwater shrimps of the family Atyidae (Crustacea: Decapoda: Caridea) from peninsular Malaysia and Singapore. Raffles Bulletin of Zoology 55:277-309. [link to PDF]

According to this paper, Atyopsis moluccensis aka Singapore shrimp/wood shrimp/bamboo shrimp/Asian fan shrimp is found in Peninsular Malaysia, particularly Pulau Tioman and Sekayu Waterfall in Terengganu, Sumatra, Sarawak, southern Thailand (including Phuket), but is not present in Singapore at all.

Here's the list of Caridina shrimp species present in Singapore:

• Caridina peninsularis Kemp, 1918

Specimens collected from Singapore: Sungei Seletar (1959); Sungei Peng Siang ("12 miles from Choa Chu Kang Road") (1961).

The form that Johnson identified as Caridina brachydactyla peninsularis was subsequently lumped under Caridina simoni, but was then split off as a completely separate species. It is found in low-salinity brackish waters and in freshwater systems subject to tidal influence.

• Caridina bruneiana Choy, 1992

Specimens collected from Singapore: Jurong, 1958; Sungei Peng Siang, 1961.

This form is very similar to C. peninsularis, and can occur together with it, being found in streams or rivers with seawater influence. Currently known from Borneo and Singapore, suspected to occur in Peninsular Malaysia (but hasn't been found there yet).

• Caridina gracilipes De Man, 1892

Specimens collected from Singapore: brackish water pond at West Coast Park (1992)

Another species found in the lower reaches of streams and rivers with seawater influence.

• Caridina gracilirostris De Man, 1892

Specimens collected from Singapore: Sungei Simpungkii at Sembawang Road (1961); Sungei Seletar (1959)

• Caridina propinqua De Man, 1908

Specimens collected from Singapore: Sungei Buloh mangroves (1991, 1992, 1999); Mandai Kechil mangroves (1992); Mile 12, Jurong Road (1959); Sungei Seletar (1995)

Found in mangrove creeks and other estuarine environments; the specimens from Mile 12 were collected in peaty ditches that flowed through coconut plantations.

• Caridina sumatrensis De Man, 1892

Specimens collected from Singapore: Lombong Stream (1990); Jurong (195

The form that Johnson identified as Caridina weberi sumatrensis has also been split off as a completely separate species. Occurs in rivers and streams.

• Caridina temasek Choy & Ng, 1991

Specimens collected from Singapore: Sime Road (1990)

Occurs only in forest streams in the Sime Road area in Singapore, but is known from a wider variety of habitats in Peninsular Malaysia, southern Thailand, and Sarawak and West Kalimantan.

• Caridina johnsoni (new species)

Specimens collected from Singapore: Lower Peirce Reservoir (1990); Nee Soon Swamp Forest (1990); Pasir Laba, Tengeh Reservoir (1990); Sungei Seletar (1959)

The form that Johnson identified as Caridina tonkinensis has been described as a new species. Specimens from Lower Peirce Reservoir formerly identified as Caridina propinqua also belong to this species instead.

Widespread and recorded in a variety of habitats, including reservoirs, lakes, rivers, and streams.

• Caridina malayensis (new species)

Specimens collected from Singapore: Nee Soon Swamp Forest (1990, 1994, 1995, 199

Found in acid-water forest rivers, streams, or black water in peat swamps.

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Identification of the many species of shrimps still requires detailed examination of the anatomy, but at least here's an up to date list of what we've got here in this little island.

[Navanod]

Any chance all the pictures of these shrimps can be found?
Detailed examination would require hours of microscopy work and fresh samples...followed by genetic analysis for confirmation. I'm going to leave that to the profs and docs at RMBR, hehe

The "Singapore" shrimp was given this trade name because many western countries got their sources from Singapore initially I believe. Not because the shrimp is native to our shores.

It's interesting that people are taking an interest in native shrimps, as the industry and the hobby are usually more interested in trade shrimps. Wild shrimps, with the exception of the Sulawesi shrimps, are often overlooked.

[Draka]

It is interesting but catching on as a hobby for native shrimp might not be possible unless they are sufficiently unique I feel. Anyway its interesting how the brachydactyla looks a little like gracilirostris...

[Trichopsis]

Yeah I agree that it's more for the sake of personal curiosity; I don't think the local shrimps could compare with a CRS or Sulawesi shrimp in terms of colour or attractiveness. Unfortunately, there don't seem to be many photos of these species. There are quite a number of photos of propinqua and gracilirostris, but I doubt they represent specimens collected from Singapore. Similarly, there is a small handful of photos depicting temasek and sumatrensis.

Still, if anyone is interested in trying to recreate a Malaysian/Singapore stream/lake biotope, this is a good place to start. And I've always been personally fascinated with what's present here in Singapore.

[Draka]

Haha just curious, do you have your set-ups in NUS itself? And actually, gracilirostris are found in singapore. Its the propinqua that differs from what is traded in the LFSes.

[Trichopsis]

Nope, I only recently started out with a single setup at home (in January this year), hoping to be able to maintain it in the long-term while featuring local fishes and hardier invertebrates such as various shrimps and snails.

And yes, I was wondering where it was possible to find wild gracilirostris in Singapore. So the wild ones here are similar (if not identical) to the ones in the LFS?

[Draka]

I haven't seen them, to be completely honest with you. But they should be similar, if not identical. But if they are described as gracilirostris, they would have the same red rostrum, transparent to translucent body with a vein (?) near the underside of the body able to change colour and with the same basic body shape. Even if they aren't actually the same species, you should be able to find shrimp fitting that exact description. The only difference might be size and proportions that's all. As for finding it, you'll need the help of the other bros haha, I don't actually know where to get them. Plus, there's the drawback of breeding

And wow, how big is your tank?

[stormhawk]

Since it is a brackish species, perhaps spots like Kranji Park might be worthwhile. There was a type of shrimp that inhabited the pond near KK Hospital. I don't know what species they were but they fed willingly on crumbs of bread. I'm not sure if they are still there though.

[Draka]

Ah, good old Kranji park with wonderful amounts of clams... Wouldn't be surprised at shrimp there.

[Draka]

Anyway Pseudo, just to let you know CRSHaven in the east has these weird shrimp they call "wild white cherry", got two last week to look at them more closely at home. They look most like brachydactyla as compared to any other shrimp...

[Trichopsis]

Thanks for the heads-up! And it's so close to my home... My priority is to get some of the shrimps that Shaihulud wrote about in the other thread, but I'll keep an eye out for these ones as well. How much are these "wild white cherry" shrimps selling for?

[Draka]

A dollar each. I got a female that was pregnant and isolated it to see what the fry would be like. The fry seemed to be larvae for a day before actively moving around after that. Fully freshwater. The only problem is I thought they would be able to take sulawesi parameters and...

Anyway, do let me know what Shaihulud has please!

[stormhawk]

The last time I had shrimp that produced pelagic larvae were Malayan Shrimps. I remember seeing a tank full of the larvae jerking about.

Wild white cherry? If these are wild N. heteropoda, they're not in the list above.

[Draka]

The rostrum and general body shape does not fit a N. heteropoda, which is why I mentioned he might want to check it out. I asked why they were called wild white cherry cause they don't look anything like heteropoda close up and they said it came with the malayan but weren't malayan but the supplier called them wild white cherry. Got the only pregnant female cause I thought it'd be fun to see how they were like. But too bad lost them.

[Trichopsis]

Fascinating. It seems like I really need to prepare a small vial of alcohol.

I'm more keen on Shaihulud's shrimps, and I've made arrangements to get some from him later next week, so my priority is to see if I can keep them alive, and if possible, sacrifice some to be preserved and sent to the museum. Hopefully they can be identified.

I might consider picking up some of these wild white cherries, though I'm currently debating whether I should attempt to start a colony, or just buy 5 or so and plop them into alcohol straightaway.

Oh, I work in research, so I've learned to be quite heartless where it comes to killing invertebrates with alcohol.

[Draka]

Thank god. I was almost ready to suggest passing one to you in school when you said "sent to the museum"...

[Navanod]

I might consider picking up some of these wild white cherries, though I'm currently debating whether I should attempt to start a colony, or just buy 5 or so and plop them into alcohol straightaway.

Oh, I work in research, so I've learned to be quite heartless where it comes to killing invertebrates with alcohol.

I used to be from the mortuary and lab animal facilities. After cutting up dead human and euthanizing so many vertebrates, I finally found my heart again and resigned.
Why are you trying to preserve the white cherries?

[Trichopsis]

Why are you trying to preserve the white cherries?

I'm also interested in seeing if it's possible to pin down the identity of these shrimps, which means having to work with freshly dead specimens, since it appears that the only way to tell apart many different species of shrimps is by examining the minute anatomical details under the microscope. This is especially the case for the white cherries, since the name could be misleading; these might be white colour morphs of typical cherry shrimps, another separate (but already known) species, or even a completely new species that has yet to be described by science to date!

I could keep the shrimps alive, and wait for one to die of natural causes, but there is always the risk that by the time I discover that a shrimp has died, the body has already deteriorated so severely that its useless for ID purposes, or that the body has been eaten by scavengers. If there's any chance of getting the Raffles Museum, or any of the other researchers to pin down the ID of these shrimps, then they will need to work with specimens that have been preserved beforehand in alcohol, preferably multiple specimens. These can then be catalogued and stored in the museum's collections.

It's definitely unpleasant, but it's a necessary part of identifying small invertebrates, especially for those that don't have distinctive colours.

[Draka]

They aren't white by the way, just bought 4 of them. They cannot take pH8 water, but can go from 6.5 to 7.5 according to the seller. However, my tank is pH 6.0 and they seem fine the past week, all measurements by Sera liquid tester. Blueish to brown coloration, but pale.

[Trichopsis]

Interesting. Any chance of photos?

Was wondering if the supplier had caught these from the wild (from I don't know, somewhere in Malaysia?), or if these were raised in a farm somewhere. Are Malayan shrimps farmed these days, or wild-caught?