Redis­cov­ery of the sap­phire from Bangka: Parosphromenus deiss­neri

Redis­cov­ery of the sap­phire from Bangka:

Parosphromenus deiss­neri

By Went­ian Shi, 2018

In spe­cial thanks to P-​Project and Peter Finke; Team Bor­neo and

my team­mates Ji, Yuhan and Dai, Jian­hui

Bangka Island is a very small island lies between Suma­tra and Bor­neo, whose area is just about one thir­ti­eth of Ger­many. It is a spe­cial bio­log­i­cal bridge, where the species from Suma­tra and species from Kali­man­tan meet each other, which leads to a great bio­di­ver­sity. As a par­adise of labyrinth fish and a wit­ness of a great evo­lu­tion in the past mil­lions of years, Bangka is the home of 2 Parosphromenus and 5 Betta species. Parosphromenus deiss­neri is the swim­ming Sap­phire of Bangka

It is a leg­end of a his­tory of 150 years and the flag-​ship species of her genus. Besides, the island is one of the two orig­i­nal loca­tions of nomino­typ­i­cal sub­species of P. bin­tan, which is the most widely dis­trib­uted species of this genus (from Suma­tra, Bangka Beli­tung to Riau Arch­i­pel­ago). 3 of its 5 betta species are endemic ones: bur­di­gala, chloropha­ranyx and schal­leri; the first two are endan­gered species on the IUCN list;

Despite its great bio­di­ver­sity, Bangka, as a sep­a­rated small island, has never exported its fish com­mer­cially like Kali­man­tan or Suma­tra due to the dif­fi­cul­ties of trans­porta­tion. Species like deiss­neri was only pri­vately intro­duced into the West few times in the past 20 years by experts like Mr. Linke or Mr. Brown since it was re-​descripted by Mr. Kot­te­lat (Between its first descrip­tion in 1859 and the re-​description in 1998 the con­di­tion of this species remained unknown for almost 150 years.). The con­di­tions of the habi­tats were also rarely reported since the first descrip­tion, because of the incon­ve­nience for travel.

In 2012 Mr. Zhou from China, Jun­gle Michael from Malaysia and Team Bor­neo from Japan con­ducted a search in Bangka. They checked all known habi­tats and found all 7 known species. Excited by their report I decided to find and keep deiss­neri myself in 2015. But the real­ity at that time was frus­trat­ing. I couldn’t find this species any­where in EU. The Parosphromenus-​Project informed me that all known strains of deiss­neri in the west were lost (later it turned out to be that at that moment this species was com­pletely lost in cap­tive around the whole world); and there was no visit to their habi­tats on the island since 2009, either (The 2012 expe­di­tion in the east was then unknown to the west.). With great con­cern and uncer­tainty about this leg­endary fish, I began my first visit to Bangka in 2016.


I arrived in Pangkal Pinang in August 2016 together with my team­mates Ji, Yuhan and Dai, Jian­hui (Team N.J.B.). The severe dam­age to the envi­ron­ment of Bangka due to min­ing and oil palm pla­na­tion was already vis­i­ble from the plan. (Fig 1)

It was not a good sign for us. To find P. deiss­neri we planned to check all known Habi­tats (which kindly offered to me by Mr. Linke,), espe­cially their Holo­type loca­tions. The actual sit­u­a­tion of the Biotope was far more worse than we expected. The orig­i­nal habi­tats of deiss­neri were the small branches and swamps of the biggest river sys­tem of the island, which lies in the cen­ter area of Bangka. They were found by Mr. Kot­te­lat and Mr. Linke in 1998 and 2008 in the mid­dle range of this river, so called the tra­di­tional dis­tri­b­u­tion area. But the whole area from the moun­tain, where the river ori­gins, to the mid­dle range was turned into a vast oil palm farm (at least 50 quadrat kilo­me­ter). The swamps and small branches there were severely pol­luted or destroyed by the oil-​palm plan­ta­tion (Fig 2)

The two known habi­tats were gone. The swamp with high pop­u­la­tion den­sity in the past was com­pletely dry. The small black water river was pol­luted by the farm and turned into a shal­low muddy stream.(Fig 3)

We tried to walk through the remain­ing for­est and find new loca­tions with good water in the upstream areas, but what hided behind the trees was newly built oil palm farm. .(Fig 4)

The local peo­ple burned down the trees inside the for­est, so that the farm would not be rec­og­nized from out­side. We searched for 3 days, and we can’t find any proper water sys­tems for parosphromenus in this tra­di­tional dis­tri­b­u­tion area. What we got here was only the most robust Betta species, edithae. .(Fig 5)

which can sur­vive in almost all water con­di­tions. Then we turned south to the loca­tion of the new Holo­type of deiss­neri, where this fish still existed until 2012. But the river was com­pletely pol­luted in 2015 by a new oil-​palm farm directly alone the river. The for­est was burned down, and a pump­ing sta­tion for the palms was built directly beside the find­ing posi­tion of the Holo­type in 1998. .(Fig 6)

Although the water con­di­tions and water plants have already recov­ered in 2016 (black pH 4,8; GH<0,5). .(Fig 7)

and many fish species came back, the pop­u­la­tion of the P. deiss­neri was not reestab­lished. We searched around this loca­tion for 3 days and found only B. edithae, Belon­tias, Chan­nas and Ras­b­o­ras.

Since all known loca­tions were lost, we had to give up search­ing for deiss­neri. Instead we decided to col­lect the other impor­tant gem of Bangka, Betta bur­di­gala. (Fig. 8)

This red endemic species, the swim­ming ruby of Bangka, is extremely rare, because it has only one habi­tat across the whole island, a small black water swamp at the far end of the island. Luck­ily, we found out that this swamp was still in per­fect con­di­tion with per­fect clear black water. (Fig. 9)

Unluck­ily, the swamp was so healthy, that the water level was too deep to catch small betta of coc­cina com­plex. Only 3 exam­ples were col­lected in 2012, and we didn’t have the luck at our side this time. But we got chloropha­ranyx and were con­fi­dent that bur­di­gala was still swim­ming here.

At the last day we decided to check the habi­tats of B. schal­leri and P. bin­tan. The region of these two species was rel­a­tively well pre­served from human activ­i­ties. We dis­cov­ered a new river with clean water, where schal­leri and bin­tan lived (Fig. 10, 11a, 11,b))

It was a deep (1m near the bank) fast flow­ing small river with half black water. The pH was around 5,1 with a cool water around 2627 degree in the noon. It was heav­ily cov­ered by plants along the bank. (Fig. 12)


and under the water the great colony of Cryp­to­co­ryne long­i­cauda and bankaen­sis pro­vided shel­ter for many fish sp.

(Fig 13 a, b, c)

In such a small habi­tat we man­aged to find 15 fish species, includ­ing Bar­bi­neas, goby, loach, juve­nile of cat fish etc. It reminded me the real mean­ing of bio­di­ver­sity in the tropic.

And in this spot, we met an unex­pected rare guest: Sun­dadanio gar­gula (Fig. 14)

The endemic Sun­dadanio of Bangka. It was the first time that liv­ing sam­ples of this species were pho­tographed. My first trip to Bangka ended with great con­cern about the envi­ron­ment of this small island, and espe­cially about the sur­vival chance of deiss­neri.


Although all known habi­tats of deiss­neri were lost, I didn’t want to give up. Thus, I checked for months on maps to find poten­tial habi­tats of this species and got in touch with Team Bor­neo through the help of Mr. Finke. Six months later I arrived in Bangka for the sec­ond time in Mar. 2017 with my team­mate Ji. We went directly to the loca­tion of the new holo­type of deiss­neri. This time we drove around the oil-​palm farm to the very upstream area. Then we went on foot along the river across for­est to a small branch of the river, which is not yet pol­luted by the farm. I got it in my first try, a beau­ti­ful adult male with long fil­a­ment on tail (Fig-​15 a,b)

What a dis­cov­ery! Finally, I redis­cov­ered this fish. The water is clear not black, with a pH of 5.1, elec­trolytic around 6 μS/​m at a water tem­per­a­ture of 27.8°C. The bank area of the river is around 0.51,2m deep and heav­ily cov­ered by plants. The fish was hid­ing among the plants or in the holes under the wood, (Fig-16a,b,c).

We also found many Ras­b­o­ras, choco­late gourami (Fig 17).

betta edithae, betta simo­rum etc. together with deiss­neri. But the pop­u­la­tion den­sity of deiss­neri in this habi­tat was extremely low. We could get only less than 10 spec­i­mens from this area. The rea­son was that the water con­di­tioned changed. Accord­ing to all ear­lier reports deiss­neri lived in black water. The water in this river sys­tem was also once black in 2008. But in 2017 it changed into clear water in the upstream area, because of the defor­esta­tion. The Parosphromenus can adapt to clear water but can­not sur­vive in a very high pop­u­la­tion as in black water sys­tem. After­wards we decided to search the orig­i­nal habi­tat of the old holo­type, where it was firstly dis­cov­ered 150 years ago. It lies in the down­stream area of the same river of the tra­di­tion dis­tri­b­u­tion area. But the devel­op­ment of the small town and mine nearby has destroyed the for­est and the river. No Parosphromenus could be found from their very first home any­more. In the fol­low­ing days we searched once again along the river of the tra­di­tional dis­tri­b­u­tion area between the down­stream posi­tion in 1859 and the mid­dle area in 1998. But all my can­di­date loca­tions failed me. We man­aged to find a beau­ti­ful very orig­i­nal swamp. The for­est there was per­fectly pre­served. We even saw a group of mon­keys jump­ing here and there (Fig. 18 a, b)

But the water was strange, half clean half tur­bid. I sup­posed in some­where of upstream area the local peo­ple were burn­ing down for­est and dig­ging canals for oil palm, which pol­luted parts of the water resource of this swamp (Fig– 19)

There­fore, we could not find any typ­i­cal black water fish here.

After that we went to the swamp of bur­di­gala. Unfor­tu­nately, the won­der­ful swamp was partly destroyed just in 6 months by ille­gal wood cut­ting (Fig. 20)

What remained can’t keep as much water as before. The huge colony of cryp­to­co­ryne bankae­n­e­sis down­stream was also partly destroyed due to the bad water con­di­tion (Fig-​21).

The water depth dropped to an aver­age of just 30 cm. It was an ideal water level to catch bur­di­gala (Fig-​22).

But it did not promise a bright future for this species, because this swamp is their only habitat.

4 days after my arrival Team Bor­neo joined us. We went to his secret loca­tion, which was our only hope in the tra­di­tional dis­tri­b­u­tion area of deiss­neri, where he caught hun­dreds of spec­i­mens in 2012. But the envi­ron­ment there changed dra­mat­i­cally. The ear­lier forests were replaced by oil-​palm farm. The orig­i­nal black water river was now a half dry muddy stream, whose water was leaded by irri­ga­tion canals for the oil-​palm (Fig-​23).

Noth­ing remained. He lead us then to his loca­tion of the mys­te­ri­ous east­ern type of deiss­neri. The rivers of this type were already pol­luted by Tin min­ing ten years ago (Fig-​24).

Now the remain­ing for­est in this area was also burn down to build houses. We decided to search around my new loca­tion. We found a huge swamp a few kilo­me­ters away of my loca­tion near anoher big oil-​palm farms. But no deiss­neri lived there (Fig-​25).

We con­firmed the bound­ary of the cur­rent dis­tri­b­u­tion of deiss­neri, that they are lim­ited in the very upstream area. We turned back to the small branches in the upstream area and found two more small habi­tats. The prob­lem is that, the habi­tats are all frag­men­tal and are already partly affected by the human activ­i­ties in this area. The rain­for­est and swamps are too small. The orig­i­nal black water changed into clear water. The fish strug­gled to adapt to the new envi­ron­ment. Thus, the pop­u­la­tion den­sity of these habi­tats is very low.

At the end we decided to go into the heart of Bangka, which was never sci­en­tif­i­cally searched before, to look for new habi­tats of bur­di­gala or deiss­neri. In this vir­gin land we suc­ceeded to dis­cover 3 more loca­tions of deiss­neri, where we also caught B. simo­rum and B. chloropha­ranyx. . (Fig-26,27).

One of the new loca­tions is a black water swamp, which hides in an untouched rain for­est (Fig-​28).

It is the only remain­ing black water swamp habi­tat of deiss­neri we have dis­cov­ered. The fish from such water con­di­tion show mag­nif­i­cent dark blue color after cap­ture, like a sap­phire (Fig. 29)

I returned to Bangka 6 months later once again with my Team­mate Dai, because we wor­ried about the con­di­tion of that habi­tats. The scenes we had seen at that time were very frus­trat­ing. The process of defor­esta­tion in Bangka is so rapid, that just in 6 months one of the newly dis­cov­ered habi­tats of deiss­neri in the remote area was burned down (Fig-​30).

The ille­gal wood cut­ting also con­tin­ued in the habi­tat of bur­di­gala, and the water level dropped to no more than 10 cm. The bur­di­gala strug­gled in the shal­low muddy water. The only hope was the for­est deep inside, where the local peo­ple not yet touched. We also checked the habi­tat of bin­tan. It was also in dan­ger; the peo­ple were build­ing house beside the habi­tat and con­structed a wood water gate across the river (Fig-​31).

The pop­u­la­tion of bin­tan dropped sig­nif­i­cantly. No bin­tan could be found down the water gate. Only a few of them were caught in the upstream area. There­fore, we searched fur­ther into the remote areas along the river sys­tem for bin­tan. We man­aged to find a huge black water swamp in per­fect con­di­tion with very high pop­u­la­tion den­sity of bin­tan (Fig-​32).

But how fur­ther can we go next time? The island is lim­ited. We can’t expect for hid­den vir­gin land for­ever. With­out pro­tec­tion, the loss of all habi­tats is only a mat­ter of time.


I went to Bangka for the fourth time six months later, in April 2018. The ille­gal wood cut­ting in the habi­tat of bur­di­gala seems to be stopped, and the water level recov­ered com­pletely. A warn­ing sign from the local police was set up. It sug­gested that the local gov­ern­ment might have taken some actions at last. There­fore, I believe that this habi­tat might sur­vive for at least another 5 years. The habi­tats of deiss­neri seem to be also more or less main­tained with­out big changes. But the sur­vival of these habi­tats are only of a result of luck and under direct threat. Some new con­struc­tions of oil palm plan­ta­tion near the habi­tat of the new holo­type were already under way (Fig-​33).

Another habi­tat for a Betta species was also in this period destroyed (Fig-​34).

In so far, the expand­ing of oil-​palm farms and Tin-​mining con­tin­ued with­out any lim­i­ta­tion on this small island, I am not sure how long these habi­tats may last under the threat of the human activ­i­ties. Although I redis­cov­ered deiss­neri with great plea­sure, at the very moment I real­ize in great sor­row that they are in great danger.

Keep­ing and Breed­ing in Tanks

To keep and breed deiss­neri in tank is not a dif­fi­cult task. There are no spe­cific require­ments for this species in com­par­i­son with other parosphromenus species. They are not aggres­sive and can be kept in a group of 810 in a 50 L. tank (60X30 stan­dard size) (Fig-​35).

The male can reach a size of 4 cm, with a very long fil­a­ment of tail. The fil­a­ment itself can reach 0,51 cm long. The female is slightly smaller with no blue color on fins, but a dark red on the cen­ter of the tail. The female also has a short tip on tail, just arount 1mm long. The deiss­neri are very robust. They can adapt to dif­fer­ent water con­di­tions, even to a hard water of GH 1520. They are not very sen­si­tive to inor­ganic chem­i­cal para­me­ters of the water, when in cap­tive. But nat­ural soft acid black water is much bet­ter for the fish, and they only dress up their metal blue color in such con­di­tion. I usu­ally keep the fish in a black water of pH 55.5, GH 23. On the other hand, the organic fac­tors are very cru­cial for them, which means they require a good nitro­gen cycle. Deiss­neri are not picky mouths. They accept all kinds of liv­ing food ani­mals: BBS, grindal, Moina, Culex-​larva etc. The most dif­fi­cult part of keep­ing wild catch deiss­neri is to work against Oodinium/​pepper spots. They are very easy to be affected by these par­a­sites. A reg­u­lar water change is nec­es­sary, and an early treat­ment is very impor­tant when they get affected. With cor­rect med­i­cine they can be cured in a short time in early period of the affec­tion. The tank breed gen­er­a­tions are much stronger against Ood­inium. They are rarely affected. They can live at least 23 years. I am not sure about the life span of this species in cap­tive, since the wild catches are still active after 2 years. They should not be kept in warm water above 28 degrees. They can sur­vive even when the water tem­per­a­ture is above 32 degrees. But it is not nat­ural and will shorten their life spans. They live in cool water in wild. Even in dry sea­son at noon the water is around 2728 degrees. In the night it falls around 20 degrees or lower. Accord­ing to my expe­ri­ence, for an apart­ment in EU with nor­mal heat­ing sys­tem an extra heat­ing in tank is not nec­es­sary even in win­ter. It is only nec­es­sary if the water tem­per­a­ture drops below 1618 degrees.

To breed them, a seper­ate tank for a sin­gle pair is rec­om­mended. The breed­ing tank doesn’t need to be very big, 10 L. to 20 L. is enough, but the big­ger the tank the bet­ter for the female and eas­ier to start a courtship. The courtship can last 23 days (Fig-36,37).

The spawn­ing will last a few hours (Fig-​38).

The female will leave the small hole, where the male guard the eggs in an under­wa­ter bub­ble nest (Fig 39 a, b)

The male may attack the female in this period. If the tank is too small, it may lead to an injury of the female. After 68 days the next gen­er­a­tion will develop to a stage of being able to swim hor­i­zon­tally. They may stay in nest for an extra 23 days (Fig. 30)

Either a sep­a­rate of the par­ents or the next gen­er­a­tion is pos­si­ble. The juve­niles of deiss­neri are of a size of only 12 mm. They require small first food. Para­me­cium or small artemias are accept­able for the first week.

In the past 2 years I have vis­ited Bangka four times. I have wit­nessed the dra­matic envi­ron­men­tal degra­da­tion hap­pened on this Island. Oil palm plan­ta­tion con­tributed the most severe dam­age to the rain for­est. It hap­pens not only in Bangka, but all over the whole Indone­sia. For such a small island the loss of one swamp might mean the loss of one species for­ever. It took the nature mil­lions of years to cre­ate the fab­u­lous bio­di­ver­sity in Bangka, it might just take a few decades to lose it for­ever. What can we aqua-​fans do to pre­vent such a tragedy? I think cur­rently the best answer is to pre­serve the habi­tat from human inter­fer­ence by pur­chas­ing it from the local peo­ple. It is also the stan­dard pro­to­col for the pro­tec­tion projects for Orang­utan and Tiger in Indone­sia. The big mam­mals get a lot of atten­tions from the pub­lic, but not the small fish like Parosphromenus or Betta under water. Thus, a pri­vate con­ser­va­tion area specif­i­cally estab­lished for small fish species might be cru­cial for their sur­vival. For exam­ple, a tiny pri­vate land is pur­chased by my Japan­ese friend. He pro­tects one Betta species per­ma­nently by doing so. It is proved to be an effec­tive solu­tion. This is also the aim and works of the Parosphromenus – Project, to evoke pub­lic atten­tion and estab­lish con­ser­va­tion areas for these species.

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