Hampala katibas, Hui & Grinang & Jongkar, 2025

Hampala katibas , new species

( Figs. 4–6)

Hampala bimaculata View in CoL (non-Popta) – Cramphorn, 1978: 31, 32, 34; Choy & Chin, 1994: 765; Doi & Taki, 1994: 411 (part); Kottelat & Lim, 1995: 230 (part); Sulaiman & Shahdan, 2003: 62; 2007: 21; Abdullah, 2004: 20 (Table of fish recorded from Batang Ai National Park); Sulaiman et al., 2018: 28; 2023: 59.

Hampala macrolepidota View in CoL (non-Valenciennes) – Parenti & Meissner, 2003 (in part): 39.

Holotype. ZRC 65740, 128.8 mm SL; Sarawak: Song District : Rejang River basin: Katibas River : Ulu Katibas , Sungei Merating, draining into Sungei Bloh ( 01°38.045′N 112°17.350′E, 121 m asl); 2018. GoogleMaps

Paratypes. ZRC 60144 View Materials , 2 ex., 79.2–119.2 mm SL; Sarawak: Song District : Rejang River basin: Katibas River : Ulu Katibas , Sungei Merating, draining into Sungei Bloh ( 01°38.045′N 112°17.350′E, 121 m asl) GoogleMaps ; 2018. --- ZRC 60118 View Materials , 3 ex., 83.7–125.3 mm SL; Sarawak: Song District : Rejang River basin: Katibas River : Ulu Katibas, Sungei Kemau ( 01°38.341′N 112°16.118′E, 130 m asl) GoogleMaps ; 2018. --- ZRC 59973 View Materials , 1 ex., 101.2 mm SL; Sarawak: Song District : Rejang River basin: Katibas River : Ulu Katibas , Sungei Datai , draining into Sungei Bloh, about 5 mins down river of Nanga Bloh Field Station ( 01°39.015′N 112°16.765′E, 100 m asl) GoogleMaps ; 2018. --- ZRC 60097 View Materials , 1 ex., 70.5 mm SL; Sarawak: Song District : Rejang River basin: Katibas River : Ulu Katibas, Sungei Jih ( 01°38.932′N 112°15.735′E, 172 m asl) GoogleMaps ; 2018. --- ZRC 65389 View Materials , 2 ex., 110.3–119.7 mm SL; Sarawak: Bintulu, tributary of Sungei Kemena; 2007 . --- ZRC 65396 View Materials , 4 ex., 113.3–140.8 mm SL; Sarawak: Bintulu, Kemena, Hulu Sungei Kalabat; 2007 . --- ZRC 35870 View Materials , 1 ex., 172.6 mm SL ; ZRC 35889 View Materials , 1 ex., 129.7 mm SL; Sarawak: Sungei Baram (SS 3A/B); 1980 . --- ZRC 38407 View Materials , 1 ex., 116.1 mm SL; Sarawak: Sungei Baram, Sungei Lawa, Long Pila area ; 1981 . --- BMNH 1978.3 .20.63, 1 ex., 41.1 mm SL; East Malaysia: Sarawak: Baram basin, Sungai Terikan, Lobang Cina; Cramphorn J, 1 January 1977 . --- BMNH 1978.3 .20.65, 1 ex., 27.4 mm SL; East Malaysia: Sarawak: Baram basin, Sungai Lansat; Cramphorn J et al, 1 January 1977 .

Non-type material. ZRC 49790 View Materials , 2 ex., 232.5–275.4 mm SL; Brunei Darussalam: Belait River, Sungei Ingei camp; 1996 . --- ZRC 65471 View Materials , 1 ex., 76.4 mm SL; Brunei Darussalam: Temburong district: Belalong basin; Sungai Esu, about 15 minutes upstream of Kuala Belalong Field Studies Centre ; 2001 .

Diagnosis. Hampala katibas , new species, can be distinguished from its congeners by the following combination of characters: lateral line scales 25–26 (mode 25); two black bars on body, bar 1 2–5 scales wide more intense black in the middle, bar 2 1½–4 scales wide, all bars apparent even at juvenile stage; upper and lower edges of caudal fin with a black marginal band; all fins orange in life.

Description. See Table 1 for biometric data and Figs. 4–6 for general appearance.

Head pointed, wedge-shaped, head large (32.1–38.2 % SL). Mouth terminal, gape oblique and large with posterior edge beyond anterior margin of eye; with a pair of maxillary barbels, each barbel at corner of mouth, as long or longer than eye diameter. Relatively large eye (eye diameter 13.8–25.5 % HL), and long snout (snout length 30.4–35.6 % HL). Body relatively compressed, elongate and deepest at dorsal-fin origin (body depth at dorsal-fin origin 25.1–33.5 % SL; body depth at anus 17.1–21.6 % SL), tapering to narrowest at caudal peduncle (caudal peduncle depth 11.4–13.4 % SL). All fins triangular in outline, except caudal fin which is deeply forked (upper caudal lobe 28.1–37.0 % SL, median caudal 11.4–14.7 % SL, lower caudal lobe 25.9–36.6 % SL). Dorsal fin moderately short with 11½ rays (dorsal-fin base length 13.7–17.2 % SL), positioned past mid-body (predorsal length 53.3–56.0 % SL). Anal fin short with 7–8 rays (anal-fin base length 9.2–11.2 % SL), pre-anal length 74.0–79.4 % SL. Pectoral fin moderately long with 15 rays (pectoral fin length 17.4–21.5 % SL). Pelvic fin shorter than pectoral fin with 10 rays (pelvic-fin base length 15.5–19.3 % SL), prepelvic length 50.8–55.9 % SL. Pelvic auxillary scale present, about ⅓ pelvic-fin length.

Lateral line complete, perforating the large scales in a continuous series (25–26, mode 25), starting just above opercular opening, gently sloping downwards towards pelvic fin, 2–3 scales (mode 3) above pelvic-fin origin and running parallel to venter towards middle of caudal peduncle, with additional 2–3 (mode 3) perforated scales on caudal-fin base. Predorsal scales 9–10; 8th lateral-line scale in relation to dorsal-fin origin; 15–17th (mode 15th) lateral-line scale in relation to anal-fin origin; 7½–8th (mode 7½th) lateral-line scale in relation to pelvic-fin origin. Circumpeduncular scales 12–13.

Fresh colouration. See Fig. 4. Body silvery-gold, posterior margin of each body scale with thin band of melanophores, greyish-brown on dorsum, cream on venter. Opercle with orangish sheen when live. There are consistently 2 black bars on the body. Bar 1 originating at dorsal-fin origin (lateral line scale 9–14), bar width may cover entire dorsal-fin base and narrowing downwards from 5 to 2 scales wide, bar at median of body 3–4 scales wide. Bar 2 originating at lateral line scale 19–24, wider at dorsum and narrowing downwards from 4 to 1½ scales wide, bar at median of body 2–2 ½ scales wide. In larger specimens, both bars are not continuous to venter. In juvenile stage, bars 0 and 2 are rounded black blotches, bar 1 is narrow and not continuous to venter, 1–1 ½ scales wide. All fins orange-red in colour. Both dorsal and pectoral fins with black leading edge. Upper and lower edges of caudal fin with a black marginal band.

Preserved colouration. See Figs. 4–6. All bright colours are faded or bleached. Older preserved specimens may appear yellowish or brownish. Body and fin patterns as above.

Field notes. From the two locations within Lanjak Entimau Widlife Sanctuary in Sarawak, the following fish species were syntopic with Hampala katibas :

Nanga Bloh field station: Cyprinidae : B arbodes b anksi, B. kuchingensis , B. sealei , Barbonymus balleroides , B. collingwoodi , B. schwanefeldii , Cyclocheilichthys apogon , C. repasson , Hampala macrolepidota , Labiobarbus leptocheilus , Lobocheilos ovalis , Lobocheilos cf. erinaceus , Luciosoma setigerum , Osteochilus kahajanensis , O. sarawakensis , O. waandersii , Paracrossocheilus acerus , P. vittatus, Schismatorhynchosholorhynchos, Tortambra, Tortambroides ; Xenocyprididae : Oxygaster anomalura ; Danionidae : Rasbora cf. agyrotaenia , R. hosii , R. fasciata ; Balitoridae : Homalopteroides avii , H. nebulosus ; Gastromyzontidae : Gastromyzon fasciatus , G. katibasensis , G. megalepis , G. punctulatus , Katibasia insidiosa , Neogastromyzon chini , Parhomaloptera microstoma ; Nemacheilidae : Nemacheilus kapuasensis ; Bagridae : Hemibagrus bongan , H. fortis , Leiocassis micropogon , Pseudomystus inornatus ; Sisoridae : Glyptothorax major ; Clariidae : Clarias planiceps ; Syngnathidae : Doryichthys martensii ; Mastacembelidae :

Macrognathus circumcinctus , Mastacembelus unicolor ; Osphronemidae : Osphronemus septemfasciatus ; Channidae : Channa lucius ; Tetraodontidae : Auriglobus silus .

Mujok base camp: Cyprinidae : Barbodes banksi , B. kuchingensis , Barbonymus collingwoodi , Cyclocheilichthys repasson , Hampala macrolepidota , Lobocheilos ovalis , Osteochilus kahajanensis , O. sarawakensis , Paracrossocheilus acerus , P. vittatus , Tor tambra ; Xenocyprididae : Oxygaster anomalura ; Danionidae : Rasbora cf. agyrotaenia , R. fasciata , R. sarawakensis ; Cobitidae : Acantopsis cf. octoactinotos , Pangio piperata ; Balitoridae : Balitoropsis zollingeri , Homaloptera orthogoniata , Homalopteroides avii , H. weberi ; Gastromyzontidae : Gastromyzon fasciatus , G. megalepis , G. punctulatus , Katibasia insidiosa , Neogastromyzon chini ; Nemacheilidae : Nemacheilus kapuasensis ; Bagridae : Hemibagrus bongan , H. fortis , Leiocassis micropogon , Mystus singaringan , Pseudomystus inornatus ; Sisoridae : Glyptothorax major ; Clariidae : Clarias planiceps ; Belonidae : Xenentodon canciloides ; Zenarchopteridae : Hemirhamphodon kuekanthali ; Mastacembelidae : Macrognathus circumcinctus , Mastacembelus unicolor ; Channidae : Channa lucius , C. melasoma ; Tetraodontidae : Auriglobus silus .

Distribution. Hampala katibas appears to be distributed only from central Sarawak and northwards, from the Rejang River to the Tatau River (in Bintulu), the Baram River; and to Tasik Merimbun in Tutong, as well as the Belait and Temburong Rivers in Brunei Darussalam (see Fig. 10). Likely to be in river drainages in southwestern Sabah (as listed in Inger & Chin, 1962).

Etymology. Named after the Katibas River sub-basin draining into the Rejang River. Used as a noun in genitive.

Comparative notes. Hampala katibas has only two black blotches or bars on lateral of the body vs. three of H. lupar . See Table 2 for the body bar descriptor. Overall the black body bars of H. katibas are slightly narrower than H. bimaculata . For the juvenile body pattern, this difference in width is even more obvious (see Fig. 4). Bar 1 is narrow in H. katibas , covering around half of dorsal-fin base and does also not extend to the venter. Bar 2 in H. katibas is a narrower black blotch, but a wider black bar in H. bimaculata .

Based on body pattern alone (see Figs. 4, 5), H. katibas can be easily distinguished from the rest of its congeners. With its two bar body pattern, Hampala katibas can be differentiated from H. lopezi which has a central black stripe; from H. ampalong and H. salweenensis , which both have two black spots; from H. dispar , which has a single spot; from H. macrolepidota which has a single thin black bar from the dorsal-fin origin and an occasional caudal peduncle black spot; and from H. sabana , which has a single very wide black triangular bar below the dorsal-fin base.

Remarks. Doi & Taki (1994) described H. salweenensis on the basis of three specimens, with distinct differences. In their paper, they listed comparative data on the then five recognised species. In their comparative material, they actually examined H. lupar deposited in London ( Doi & Taki, 1994: 411, BMNH 1983.6.20:4 [ 1 ex.], BMNH 1983.6.20:13-14 [ 1 ex.], BMNH 1983.6.20:97-98 [ 1 ex.]) amongst the material of H. bimaculata listed. Their figure ( Doi & Taki, 1994: fig. 2) of H. bimaculata actually depicts H. lupar , which clearly shows three bars on the body.

Ryan & Esa (2006) and Esa et al. (2012) compared the mitochondrial cytochrome B of four species/forms of Hampala from West and East Malaysia (states of Sarawak and Sabah). Their analyses were based on 396 base pairs from 110 samples. Their conclusion was that there were two forms of H. bimaculata — Type A from south and central Sarawak, Type B from north Sarawak and west Sabah; the H. sabana intermediate form from Tawau is indeterminate (for more details on this intermediate form, refer to Inger & Chin, 1962); H. macrolepidota from West Malaysia shares haplotypes with material from the south and central Sarawak populations. Both the above results are supportive of this current work though the sequences used are short and they lack topotypic material of H. bimaculata (from East and North Kalimantan) and H. macrolepidota (from Java), which would have made the anlaysis more taxonomically robust. Ryan & Esa’s (2006) and Esa et al.’s (2012) study also suffers from an apparent absence of deposited voucher specimens. Their set of molecular data lends support to the recognition of a northern and a southern population in Sarawak, with a Lupar geological divide; i.e., Type A likely corresponds to H. lupar and Type B to H. katibas .

The Lupar geological divide has previously been recognised by geologists as an important geological break (e.g., Moss & Wilson, 1998; Breitfeld et al., 2018). The maximal deposition age for the Lubok Antu Mélange in the Lupar Valley (divide) is ca. 115 to 105 Ma; and this may have caused the rapid uplift and exhumation of the Schwaner Mountains which also implies the arrival and collision of the southwestern part of Borneo with the rest of the island at this time ( Zhao et al., 2021). Several other freshwater fish species pairs (north/south) also support this biogeographic hypothesis ( Rasbora kottelati / R. kalochroma by Lim (1995), Betta akarensis / B. ibanorum by Tan & Ng (2004), Hemirhamphodon kuekenthali / H. byssus by Tan & Lim (2013); Rasbora marinae / R. cephalotaenia by Tan & Kottelat (2020)).

It is possible at this juncture to differentiate the Bornean populations of H. bimaculata into three distinct species, based on a respectable series of fresh material from the type locality of H. bimaculata (Mahakam and Kayan river basins; see Fig. 10), and from south and north of the Lupar divide in Sarawak. What remains in doubt are the other populations of Hampala bimaculata sensu lato from Central Kalimantan and the intermediate form H. sabana × bimaculata (sensu Inger & Chin, 1962: 82, fig. 37). Pending availability of fresh material, no further conjecture can be made.

Among the Iban communities in Sarawak, the genus Hampala has two varieties, with the larger size having a single large bar and with the vernacular name ‘Adung’, most likely referring to H. macrolepidota . The smaller size is called ‘Juak’, referring to the other type with more than one bar, which could consist of other species including the two new species in this study. Hampala has significance in Iban parables and poems, indicating Hampala has cultural value to the community ( Ensiring et al., 2011). The other local name is ‘Sebarau’ which is broadly applied in Peninsular Malaysia and some indigenous communities in Sarawak and Sabah without referring to any specific species.

Panitvong & Tan (2025) described H. siamensis recently from southern Thailand. This taxon is not dealt with in detail herein, but can be easily distinguished from the two presently described species by having no distinct bars on the body vs. three and two body bars ( H. lupar and H. katibas respectively), and their distributional ranges.

Comparative material examined:

Hampala ampalong : ZRC 60059 View Materials , 9 ex., 80.2–97.1 mm SL; Sumatra : Jambi; 2018.

Hampala bimaculata : ZRC 45665 View Materials , 10 ex., 20.1–136.0 mm SL; North Kalimantan: Kayan River basin; Sungai Seba Ai, tributary to Kayan River ( 01°59.86′N 115°06.77′E, 550 m asl); 1999 GoogleMaps . --- ZRC 65451 View Materials , 6 ex., 15.3–91.9 mm SL; North Kalimantan: Kayan River basin; Iwan; Sungai Panan , tributary to Iwan river , ca. 60 mins upstream from Data Dian ; 1999 . --- ZRC 65446 View Materials , 8 ex., 26.5–109.5 mm SL; North Kalimantan: Kayan River basin; Sungai Nah, tributary to Kayan river , ca. 20 mins upstream of fork to

Iwan river; 1999. --- ZRC 65421 View Materials , 4 ex., 38.9–79.5 mm SL; North Kalimantan: Kayan River basin; Sungai Belanyan Tekan , tributary to Kayan river ; 1999. --- ZRC 65411 View Materials , 3 ex., 66.3–74.0 mm SL; North Kalimantan : Kayan River basin; Sungai Pingai , next to air strip, ca. 10 mins downstream of Data Dian ; 1999. --- ZRC 65457 View Materials , 3 ex., 28.9–61.3 mm SL; North Kalimantan : Kayan River basin; Sungai Busang Matu , tributary to Kayan river ca. 500 m upstream of Data Dian ; 1999. --- ZRC 65463 View Materials , 11 ex., 21.2–61.8 mm SL; North Kalimantan : Kayan River basin; Sungai I’sau, ca. 15 mins upstream of Data Dian ; 1999. --- ZRC 65420 View Materials , 3 ex., 27.2–31.3 mm SL; North Kalimantan : Kayan River basin; Sungai Nga’ha , tributary to Kayan river ; 1999. --- ZRC 66624 View Materials , 2 ex., 144.3–180.0 mm SL; East Kalimantan : Long Iram subdistrict; Mahakam River basin; Sungai Lomi and feeder streams ( 0°00.05′S 114°55.23′E, 180 m asl); 2000. --- ZRC 56311 View Materials , 1 ex., 87.3 mm SL; East Kalimantan : Mahakam River basin; SLJ Jaya II logging concession, km 84, Anak Sungei Bakung, feeding into Boh River ( 00°58.758′N 115′06.395′E, 134 m asl); 2017. --- ZRC 64528 View Materials , 2 ex., 128.6–136.6 mm SL; West Kalimantan : Kapuas River basin; Sungei Sekedam Besar , Sibau River ; 1998. --- ZRC 64527 View Materials , 1 ex., 63.8 mm SL; West Kalimantan : Kapuas River basin; Sibau River ; 1998. Hampala dispar : ZRC 39329 View Materials , 3 ex., 95.4–122.3 mm SL; Thailand: Buri Ram, Amphoe Muang ; 1994. --- ZRC 40888 View Materials , 1 ex., 184.4 mm SL; Thailand: Nakhon Rachasima (Korat) province , outskirts of town near Wat Leab , ditch near padi and vegetable fields, access via Soi Monkan Tree ( 14°59′46.9″N 102°03′02.8″E) GoogleMaps ; 1997.

Hampala lopezi : CAS 138090 About CAS , 4 ex., 54.3–190.0 mm SL; Philippines: Palawan, Busuanga Island, Barrio San Nicolas, Wayan creek ; 1940 .

Hampala macrolepidota : ZRC 43847 View Materials , 1 ex., 91.5 mm SL; Java: West Java Province: Cipipang, Ciliwong River ; 1997 . --- ZRC 44089 View Materials , 1 ex., 155.0 mm SL; Java: West Java Province: Banjar Pasar ; 1997 . --- ZRC 65888 View Materials , 4 ex., 63.3–112.0 mm SL ; ZRC 66162 View Materials , 1 ex., 185 mm SL; Java: West Java Province: Tasikmalaya, Cibalung basin; 2024 . --- ZRC 66246 View Materials , 1 ex., 121.8 mm SL; Java: East Java Province: Surabaya, Brantas basin; 2024 .

Hampala sabana : ZRC 43960 View Materials , 1 ex., 126.7 mm SL; Sabah: Danum Valley, stream at km 105 on main line west after turnoff to Borneo Rainforest Lodge ( 5°03′02.9″N 117°34′34.1″E); 1996 GoogleMaps . --- ZRC 44001 View Materials , 1 ex., 122.0 mm SL; Sabah: Danum Valley, stream at km 113 on main line west (logging road) after turnoff to Borneo Rainforest Lodge ( 5°00′37.6″N 117°31′43.88″E); 1996 GoogleMaps . --- ZRC 43936 View Materials , 8 ex., 22.5–111.5 mm SL; Sabah: Danum Valley, Sungai Palum Tambun , tribut. of Sg. Segama, upstream of Danum Valley Field Centre; 1996 . --- ZRC 40406 View Materials , 2 ex., 80.7–91.0 mm SL; Sabah: Danum Valley, Sungai Bilong at ca. km 83 on main line west after turnoff to Borneo Rainforest Lodge; 1996 . --- ZRC 45455 View Materials , 4 ex., 52.7–65.2 mm SL; Sabah: Danum Valley, Cabin stream right, km 50 on road to Danum Valley Field Centre; 1996 . --- ZRC 43987 View Materials , 7 ex., 24.3–53.5 mm SL; Sabah: Danum Valley , small tributary of Sg. Bole; 1996 . --- ZRC 65705 View Materials , 2 ex., 92.6–110.6 mm SL; Sabah: Danum Valley Conservation Area , Tembeling stream; 2015 . --- ZRC 65621 View Materials , 2 ex., 61.0– 111.4 mm SL; Sabah: Danum Valley Conservation Area , Rhino-pool stream; 2015 .

Hampala intermediate form fide Inger & Chin, 1962: ZRC 65626 View Materials , 3 ex., 103.0– 127.3 mm SL; Sabah: Kalabakan Forest Reserve , 30 m stream; 2015 . --- ZRC 65648 View Materials , 3 ex., 105.6–131.9 mm SL; Sabah: Kalabakan Forest Reserve , 0 m stream; 2015 . --- ZRC 65682 View Materials , 2 ex., 54.5–68.3 mm SL; Sabah: Kalabakan Forest Reserve, Gaharu Estate stream; 2015 . --- ZRC 65647 View Materials , 1 ex., 106.9 mm SL; Sabah: Kalabakan Forest Reserve , 120 m stream; 2015 . --- ZRC 65653 View Materials , 1 ex., 108.2 mm SL; Sabah: Kalabakan Forest Reserve, Virgin Jungle Rainforest stream; 2015 . --- ZRC 65802 View Materials , 2 ex., 31.4–35.0 mm SL; Sabah: Kalabakan Forest Reserve , 30 m stream; 2017 .

Hampala salweenensis : NSMT-P 35838 , holotype, 200.6 mm SL; Thailand: Mae Hong Son, Ban Phuei Phan, Mae Surin River (only photograph examined) .

Hampala siamensis : see Panitvong & Tan (2025).