RIVERINE CATFISHES OF KALIMANTAN , PANGASIIDAE : DIAGNOSIS , DISTRIBUTTON , AND ECOLOGY

Ihe main constrlin to cultivate wild spocies and optimrze ths production of culturcd spccics is to duo poorly.documcntrd of grnstic resources. ln the curr6nt study, it presEnts the divorsiV ot paniasiiOl cainsttei from Kalimantan. Nine hundrsds and ninety nine spscimens'iormed the core of the materlal ixamined durno this.study On €ech specimsn, 35 point to pomt m€asurement, "ou"ring th"p;s"ibi;;;;"t;; ;ifi"-;;ii :::l:I"l:l-I19 laken using diat catrpers. Data wer6 subjected to principat component anatysis. Dati :.1:lfl:.^"_9T11?9 rn cheracterzing .groups from scansr ptots between pairs of stricturing chaiaaers ioi suDsequent use In generic identification f€ys Tll'eg gonera vr'ith fourteen species exist in e-rgtn r"n iiu"r", Barito; Kahayan; KaDuas: Batano nalang; xinaOlanljn; k"v"n-l"riu, ano fr,fafraf<im. ifrey'arJ Helicophagus _typus, pteropangaius nicr6nemus, eaniasrus -iiviri.,ian, p. kunit, p. djambat. p. mdcronema P nasutus p. rithostomap; humeraiis. e. Tinao*in{enis, e iaoatrenst. e ,nJiiiii, p: meuwenhrisii, and P. mdhakamensis. The diagnosis of tre speJres, identification t"v, d"drfionli"a ecology are given.


RESULTS AND DISCUSSION
Fourteen species exist in eight main rivers in Sumatra (Table 1).Based on the analysis of 35 Table 1 measured and five counted characters, the dtagnosis of the species, the identification key of the species and the description are given below.
Key to Genera la.Slender anterior part of snout (<16.5oloHL), posterior nostrils are in between anterior nostrlls and orbit Hericophagus.lb.Robust anterior part of snout (>16.5% HL), Dosterior nostrils close behind anterior ones and above imaginary line from anteriot nostrils and orbit 2.
2a. Eye relatively large, minute maxillary barbel l<192% EO],, dorsal and pectoral fins relatively thin.oectoral fin with minute and numerous serrations on the anterior and posterior edge of the fin, and minute adipose lin Pteropmgdsius.
2b.Eye varies from small to large, relatively long maxillary barbel (>192yo ED\, dorsal and pectoral fins robust, and adipose fin relatively robust Pangasius Below, the different genera of pangasiid catfishes of lndonesia are presentd.For each genus' a key to the species is given.This is followed by a detailed description for each species recognised as valid H eli co ph a g u s Ble€ker, 1 858 Diagnosis: this genus differs from all other pangasiid genera by a short and a large premaxillary toothplate; a narrow mouth (<35olo HL): the front border ofthe snout b pierced by anterior nostrils; a slender anterior part of snout length (<165% HL); a short and a large premaxillary toothplate; the Dosterior nostrils are between and in line with the ante;ior nostrils and the middle of eyel the vomerine toothplate without additional toothplate.
Distribution: Pangasius Rinabatanganensis is endemic to the Kinabatangan Rjver in North Borneo (present Sabah), draining into the Sulu Sea, and flowing through flat a iuvial plains with a few scattered, low hill (see lnger & Chin, 1962).
Ecology: ln the present study, the guts content of five specimens were examined and hard seeds as well as small crustaceans were found in the gut.
Distribution: Pangasius lithostama is only known from middle part of Kapuas, the biggest river in West Kailmantan Kapuas River is the largest and probably has the r chest ichthyofauna of any ot the modern rivers delved from the Sunda drainage (Roberts 1989i P anga si u s h umeraris Roberts,'l 989 Diagnosis: Pangasius hurneralis ls distinguished by the following characters: single enlarged vomerlne toothplate, width three times rn its length, narrower than other endemic species from Kalimantan, length of humeral process reaches t\ivo-third of pectoral sptne length, dorsal spine robust 7 7-9.3%Nt, compared to the other endemic species, head width 14 1-156% SL Oistribution: Pangasius humeralis only occurs in the middle part of the Kapuas jn West Kallmantan [see P ,fhostoma part for explanatton] This species occurs sympatrically with P /tthoston'7a (Roberts, 1989 pers obs ) The local people differentiate between thrs spectes and P ltthostoma based on bodv riolouratlon lhev cail P humerahs black seladang and P hhosama as wl'tte seladang Pangasius nieuwenhuis,l (Popta,t9O4) Dlagnosis PanEasus neuwenhuisii ts distinguished by the combination of the following characters vomerine toothplate slngle and relatively wide, head robust (width 13.8-16.4oSL, length 21 9- 24 6ok SL. depth 9.6-122% SL), dorsal spine width 5.5-7 6% HL, snout ovally rounded, eye not vislble from above, humeral process extend beyond middle of Dectoral sPine Indonesian Fishenes Research Joumal Vol.1 1-2005   Distribution: Pangasius nieuwenhuisii is endemic to Kalimantan Timur (lndonesia) and only occurs in the Mahakam basin.The lvlahakam River is the second largest river in Kalimantan, with a course of some 920 km and a drainage area ol 77.704 R.rl' {Christensen l992).
Ecology: the stomach of the holotype contains very hard seeds or higher plants, larger seed crushed some 9 mm intact (Roberts & vidthayanon, 1991).In the present study, the author found hard seedE in the gut content When the author and fisherman did fishing, we used banana to catch the fish from the middle part of river.

SL), and anal rays 33-42
Dlst'ibutron Pangasus ts present In southern and western Kalrmantan, where it was found in the Barito River (same as type collectlon from Bleeker), In the Kapuas River and in the Batang Rajang River (Sarawak.Malaysia) The species was also recorded from North Borneo (Sabah, Malaysra) ln the Kinabatangan River (lnger & Chin, 1962) bul no specimens were available for the present study Ecology this species is omnivorous wlth a tendency to opportunism.In this study, the gut of seven specimens observed contaln small gastropods bivalves, insects, leaves, and detritus.Mature males and females of about 200 mm SL were caught at nrght in October 1996 along the banks of the l\4usi River at Sekayu.Pargaslus polyuranodon inhabits estuarles and lower reaches but it has also been obserued In upper reaches during the rainy season.
Distribution Pangas/us mahakamensis is endemic to East Kalimantan, (lndonesia) and it is presenfly only known from the type locatity, the Mahakam Rrver.
The Mahakam River is the second laroest river in Kalrmantan with a course of some 92d km and a drainage area of 77700 km'? (Christensen, 1992).
Specrmens smaller than 150 mm were collected in brackish water in the delta of the iver, while larger srzed spectmens were found in the upper part.Both environments have no vegetation on the banks, have a relatively strong current, are deep and the water is transparent Ecology. the species is omnivorous, feeding mainly on insects and small fruits (pouyaud et al ,2OO2) Pangasius sabahensrs Gustiano, Teugels &
Distribution: Pangasius kunyit is known trom most of the major drainages in Kalimantan where it was found in the Kapuas River (Pontianak, Kalimantan Barat, lndonesia), in the Barito River (Kuala Kapuas and Banjarmasin, Kalimantan Tengah, Indonesia), in the l\4ahakam River (Samarinda and Sangasanga, Kalimantan Timur, Indonesia) Ecology Marine invertebrates were found in gut contents of specimens caught in the delta of the lvlahakam River This species is also piscivorous.In all environments it lives in deeper waters.The species has been collected in fresh and brackish water.
Distribution: Pangasius rheophilus is presenfly (nown from Kayan and Berau River rn the Bulunoan Regency.Kalimantan Timur (lndonesra) pangaitus rheophtlus has been collected from freshwater near the mouth but also from the upper reaches of the two basrns In the lower reaches, the habitats consist of Iarge pools near the sea with deep and turbid waters.
In the upper reaches, the habitats consist of biq lorrenl charactenzed by lurbulent and ctear w:tel {altrtude 200,400 m).
Ecologyt information from fishermen indicates that immature specimens occur all over the basjn: mature specimens seem only present jn the upper reaches in running water Still according to local fishermen, the large spectmens are able to cross important water falls by lumping out of the water.i/ature fish were caught in November, at the beginnang of the rainy season, In the upstream part of the Bahau Raver (Kayan tributary).Reproductive behaviour is unknown Skeletal parts of small cyprinid species and remains of lrurts were coliected in the stomach of a laroe specimen (775 mm SL), molluscs predominant in stomach contents of small specimens (Pouyaud &   Teugels,2000 Pangasius nasutus (Bleeker, 1863)   Dragnosis Pangasus nasufus rs distinguished by havrng an inferior mouth, wth snout strongly prolectrng tooth band of upper jaw entirely exposed when Jaws are closed, the Jaw teeth very sharp and projected eye very small {66-13o4 HL), head robust (length 22 8-28 8% SL: width 13-17 2yo SL), caudal peduncle slender (depth 5 8,8% SL).body width 16.9- 21 7Vo SL, predorsal tength 36 1-4A B% SL, gi rakers on the first brana al arch 16-24 Distrlbution Pangasius /]asurus occurs In Ka imantan in the Kapuas Banto Batang Ralang R rve rs Ecology and reproduction this species lend to be omnrvorous.feedtng on benthic organisms, hard seed or hrgher plants and fishes (pers obs ).At present Pangas/us nasutus has an important commercial value rn Sundaic region where its capture js highly apprecrated by fishermen lt is considered as a candrdate for aquacuiture and tts reproduction in captrvity has already been achieved (Legendre, 2OOOI p. 23, 61) CONCLUSION Principal component analysis using brometric measurefllents enarble to dtstlngutsh three genera wtth lourteen spectes extst in egth main nvers (Banto lndonesian Fisheies Research Joumal Vol.1 1_2005 Kahayan Kapuas, Batang Rajang Kinabatangan, Kayan, Berau, and lvlahakam) in Kalimantan.ihey arc Hel i co ph agu s typu E, fteropang asi us mi cronemus, Pangasius macronema, p. polyuranodon, p kunyit, p. djambal, P. nasutus, p. kinabatangensis, p. mahakamensis, P. sabahensls, p. lithostoma, p humeralis, P niuewenhuisii, and p. rheophilus.

ACKNOWLEOGEM ENT
The author thanks J. Slembrouck, [4.Legendre, L Sudarto, W. Hadie, D. Sadili, O. Komarudin for their help in collecting tish samples.Special thanks due to G Teug-els for their encouragement to the present study.This paper forms part of the INCO.DC PROJECT "Catfish Asia', financed by the European Union (contract tC 18-CT 96-0043).I am also grateful to MRD for the fello/vship to complete thia studv through PMTP Prolect at KULEUVEN, Belgium.