Bangana Hamilton, 1822

E Zhang & Yi-Yu Chen, 2006, Revised diagnosis of the genus Bangana Hamilton, 1822 (Pisces: Cyprinidae), with taxonomic and nomenclatural notes on the Chinese species., Zootaxa 1281, pp. 41-54 : 43-51

Bangana Hamilton, 1822

Figs. 1 and 2

Bangana Hamilton, 1822 : 277 (type species: Cyprinus dero Hamilton, 1822 , by subsequent designation of Jordan, 1917).

Tylognathus Heckel, 1843 : 1027 (type species Varicorhinus diplostomus Heckel, 1838 , by subsequent designation of Bleeker, 1863)

Gymnostomus Heckel, 1843 : 1030 (type species Cyprinus ariza Hamilton, 1807 , by subsequent designation of Bleeker, 1863).

Altigena Burton, 1934 : 49 (type species: Varicorhinus discognathoides Nichols and Pope, 1927 , by original designation).

Incisilabeo Fowler, 1937 : 206 (type species: Labeo behri Fowler, 1937 , by original designation [also monotypic]).

Diagnosis

Bangana is distinguished from all other existing Asian Labeonin genera (sensu Reid, 1982) except Schismatorhynchos Bleeker (type species: Lobocheilos heterorhynchos Bleeker ) and Lobocheilos Bleeker (type species: Labeo falcifer Valenciennes ) by having the upper jaw fully enclosed by the upper lip, the median part (or base) of which is covered by the rostral fold. It is further distinguished by the following combination of characters: rostral fold thick, smooth and pendulous, separated from upper lip by a deep groove, disconnected from lower lip around corners of mouth; lateral portions of upper lip smooth or slightly papillose and laterally connected with lower lip; lower lip anteriorly separated from lower jaw by a transverse groove extending along length of entire lower jaw, with a free anterior margin containing numerous papillae on dorsal surface; lower jaw heavily cornified, with a sharp cutting edge; postlabial groove uninterrupted and forming a deep, transverse groove that fully separates lower lip from mental margin, or broadly interrupted or confined only to side of lower jaw, partially separating lower lip from mental region; and 10-12 branched dorsal-fin rays. Bangana differs from Schismatorhynchos and Lobocheilos in having the lower lip with a free anterior margin and bearing numerous papillae on the dorsal surface. Bangana lacks the type of lower lip characteristic of Lobocheilus (sensu Rainboth, 1996), in which the lower lip is enlarged to form a thick, fleshy pad that entirely covers the lower jaw, but is separated from it by a deep postlabial groove. In Schismatorhynchos the lower lip is characterized by a distinct, elongated, longitudinally directed, fleshy lateral lobe (sensu Siebert and Tjakrawidjaia, 1998).

Remarks

The type locality of Bangana dero , the type species of Bangana , is in the Brahmaputra River basin of India, but there is no information regarding the precise type locality, and the type specimen appears to be lost. The current identification of B. dero usually follows that of Hora (1936) (Kottelat 1998; Kullander et al. 1999). The available specimen, previously identified as Sinilabeo dero by Wu et al. (1977), is from the Yaluzangbu Jiang (Brahmaputra) basin in Chayu, Tibet, China. Since our comparison corroborates Wu et al.’s determination that this material agrees with Hora’s (1936) description and figure of L. dero ; it is therefore assigned to Bangana . The above diagnosis of Bangana is based primarily on the Chinese species of Bangana , with particular emphasis on B. dero . When extralimital congeners are taken into account, there may be slight modifications to the diagnosis as presented here.

Bangana was diagnosed by Rainboth (1996) as lacking a dorsal-fin spine and having 10-13 branched dorsal-fin rays; anterior and posterior barbels of approximately equal size; the upper lip smooth and entire and separated from snout by a deep groove; lower lip thin and present only at side of lower jaw; post-labial groove broadly interrupted and present only at sides of jaw. The genus was defined by Kullander et al. (1999) as lacking rostral barbels and having 10-11 branched dorsal-fin rays, a rostral fold with a short lateral flap, a heavily cornified lower jaw with a keratinised cutting edge, and the postlabial groove with a very short lateral extension. These two diagnoses of Bangana are actually similar, except for the presence or absence of barbels. Since our examination demonstrates that the 13 Chinese species previously included in Sinilabeo have most of the above diagnostic characters of Bangana , we consider this to be justification for transferring these species to Bangana . However, two other characters present in some other Chinese species here assigned to Bangana do not agree with the above diagnoses. The first character (i.e., upper lip not smooth, but with lateral portion having a slightly papillose interior surface [Fig. 1C]) is present in B. decora (Peters) , B. lemassoni , B. rendahli (Kimura) , B. tungting (Nichols) , and B. xanthogenys . The second character, which is exhibited by B. discognathoides (Nichols and Pope) , B. lippa (Fowler) , and B. yunnanensis (Wu, Lin, Chen, Chen and He) , is a postlabial groove that is uninterrupted so as to form a transverse groove that fully separates the lower lip from the mental region (Fig. 1B), rather than being broadly interrupted or present only on the side of the lower jaw, where it partially separates the lower lip from the mental region. These two characters require a revised diagnosis to be provided for Bangana , so as to include the above species. On the other hand, the C-shaped mouth opening (Fig. 1A) and ethmoidal furrow of both B. devdevi and B. dero (Fig. 2A) are not shared with other Chinese species of Bangana . We are hesitant to assign diagnostic value at the generic level to the last two characters, pending a phylogenetic analysis of Chinese Bangana species.

Like Jayaram (1981), Talwar and Jhingran (1991) transferred B. dero to Labeo , a genus currently known from fresh waters of tropical Africa and Asia. Reid (1985) excluded this species from Labeo and referred it to Tylognathus , which in turn was later treated by Kottelat (1985) as a junior synonym of Bangana . Despite wide acceptance of Reid’s conclusion, it remains unresolved whether Asian and African Labeo constitute separate monophyletic groups. Most authors usually restrict Asian Labeo to species such as L. dyocheilus (Kottelat et al., 1993; Rainboth, 1996). Remarkable morphological differences in the oro-labial structures exist between Bangana and the Asian species of Labeo . Bangana has the upper lip entirely adnate to the upper jaw (vs. separate from the upper jaw in Asian Labeo species); the upper jaw with plicae superficially absent (vs. present); the lower lip thin (vs. thick), and either with a postlabial groove uninterrupted, so as to form a transverse groove that fully separates the lower lip from the mental region, or broadly interrupted and confined to the side of the lower jaw (vs. narrowly interrupted at the isthmus).

Wu et al. (1977) transferred B. dero to Sinilabeo , and this action has been followed by all subsequent Chinese authors. Sinilabeo was originally erected by Rendahl (1932), based on a single 198 mm SL specimen collected by Dr. Hummel on Dec. 12, 1931, from the Jangtsekiang (= Yangtze River) near Tschungking (= Qiongqing). The specimen was referred to Varicorhinus tungting , which had originally been described by Nichols (1925) from Tungting (= Dongting) Lake, which flows into the middle Yangtze River. However, the Hummel specimen, on which the original description of Sinilabeo was based, not only lacks the diagnostic characters of V. tungting (or B. tungting ), but also does not conform to the present diagnosis of Bangana or any other known Asian labeonine genus. The type species of Sinilabeo was thus misidentified, and actually represented an undesscribed species, which was subsequently described by Zhang et al. (2006) as Sinilabeo hummeli . Zhang et al’s (2006) action makes Sinilabeo available according to ICZN Article 70.3.2 (1999 edition of International Code).

Bangana and Sinilabeo differ in details of morphology of the orolabial structures. Bangana has a smooth rostral fold (vs. a papillose fold in Sinilabeo ) with an even (vs. crenulated) distal margin. The upper lip in Bangana is fully adnate to the upper jaw, with its base (and sometimes the median portion) covered by the rostral fold; whereas in Sinilabeo the upper lip is present only on the side of the upper jaw, from which it is separated, and is missing in the median portion, which instead bears a thin, flexible, cornified sheath that is completely covered by the rostral fold. In addition, the anterior margin of the lower lip in Bangana is free with a slightly papillose dorsal (vs. ventral) surface; and the mouth opening is deeply arched, or C-shaped (vs. slightly arched or transverse).

Bangana decora was transferred by Banarescu (1972) to Cirrhinus Oken (type species: Cyprinus cirrhosus Bloch ). This action may be questioned, since Cirrhinus has an oro-labial pattern distinct from that of Bangana , and both were assigned by Zhang and Chen (2004) to the subtribes Labeonina and Banganina, respectively. In Cirrhinus , the upper lip is greatly thickened superficially, with variably-sized papillae and elongate folds, or plicae, and is separated from the upper jaw by a deep groove. By contrast, Bangana has an upper lip fully adnate to the upper jaw, with its median portion, or base, covered by a thick, smooth rostral fold.

Here, we follow Kullander et al. (1999) by including both Gymnostomus Heckel (type species: Cyprinus ariza Hamilton ) and Incisilabeo Fowler (type species: Labeo behri Fowler ) in the synonymy of Bangana . In addition, Altigena Lin (type species: Varicorhinus discognathoides Nichols and Pope ) is also considered a junior synonym of Bangana . Unaware of the fact that V. tungting had been designated by Rendahl (1932) as the type species of his new genus, Sinilabeo , Lin (1933) established Altigena as a subgenus of Osteochilus Guenther (type species: Rohita melanopleura Bleeker , by subsequent designation of Jordan, 1917) to include four then-known species: V. tungting , V. discognathoides , V. pogonifer and V. brevis . This name was, in fact, unavailable when first proposed because no type species was fixed in the original description (ICZN Art. 13.3), but Altigena later became available following designation of V. discognathoides as the type species by Burton (1934). Both V. discognathoides and V. tungting are here considered congeneric and placed in Bangana . Altigena is thus a junior synonym of Bangana .

Taxonomic and nomenclatural notes on Chinese Bangana species

The following twelve cyprinid species from southern China, which were allocated to Sinilabeo by Yue (2000), belong in Bangana : B. cirrhinoides (Wu and Lin) *, B. decora , B. dero *, B. discognathoides , B. laticeps *, B. lemassoni , B. rendahli , B. tonkinensis , B. tungting , B. wui , B. zhui ,* and B. xanthogenys . Since four of these species (here denoted by asterisks) are poorly known, we consider it desirable to provide a brief discussion of their taxonomy and nomenclature.

Wu et al. (1977) reported, for the first time, Sinilabeo dero (= B. dero ) from the Chinese Tibetan part of the Brahmaputra River. It was later further documented from the same region of Tibet by Wu and Wu (1991) and Zhang et al. (1995), and also from the Yiluowadi Jiang (upper Irrawaddy River) basin in Yunnan, southern China by Chu and Chen (1989) and Chen (1998). Outside China, this species reportedly occurs in India, Pakistan, Burma (= Myanmar), Bangladesh, Sri Lanka, and Nepal (Jayaram, 1981; Shrestha, 1981; Talwar & Jhingran, 1991). According to Hora (1936), B. dero is known only from along the southern slope of the Himalayas, ranging from Abor Hill (Arunachal Pradesh) west to Dehra Dun (Uttar Pradesh); with the Myanmar form actually being B. devdevi . The same view was shared by both Kottelat (1998) and Kullander et al. (1999). Based on this, records by Chinese authors of S. dero from the upper Irrawaddy River basin are based on misidentifications of B. devdevi .

Wu et al. (1977) recognized two states of the postlabial groove among Chinese Bangana species. The first state, which is exhibited by B. decora , B. lemassoni , B. rendahli , B. tungting and B. xanthogenys , is characterized by a postlabial groove that is interrupted and confined to the side of the lower jaw, partially separating the lower lip from the mental region. All remaining Bangana species, other than B. devdevi and B. dero , exhibit the second state, in which the postlabial groove is uninterrupted and forms a transverse groove that fully separates the lower lip from the mental region. Bangana devdevi and B. dero differ in this regard, however, with both having an interrupted postlabial groove. In large individuals (135.5-276.1 mm SL) of B. devdevi , the postlabial groove is interrupted and present only on the side of the lower jaw, and is connected to its counterpart by a shallow transverse fissure that is not uniformly continuous with the postlabial groove on the opposite side. In small individuals (64.8-133.7 mm SL), however, this groove is uninterrupted and forms a deep transverse groove that separates the lower lip from the mental region. Apparently, the observed variation in the postlabial groove of B. devdevi is associated with size, as was observed by Kottelat (1998: 24) for B. elegans . Our examination of a single 321.4 mm SL specimen shows that B. dero has an interrupted postlabial groove, a state also illustrated by Wu and Wu (1991).

Bangana cirrhinoides was first described in the genus Sinilabeo by Wu and Lin in Wu et al. (1977) from the Yuan Jiang (Red River) basin in Yunnan. Since no additional specimens were collected from the type locality, or elsewhere, Chu and Chen (1989) regarded it as a species known only in the original description. Yue (2000) identified, as B. cirrhinoides , material earlier reported as B. dero from the upper Irrawaddy River basin by Chu and Chen (1989). In fact, these reports of B. cirrhinoides are based on B. devdevi . Comparison of the type specimens of B. cirrhinoides with the upper Irrawaddy River basin material of B. devdevi shows that there are no marked morphometric and meristic differences between the two species. The original description indicated that B. cirrhinoides has an uninterrupted postlabial groove, which entirely separates the lower lip from the mental region. However, this is contrary to our observation that the type specimens (69.8-127.2 mm SL) of B. cirrhinoides have an interrupted postlabial groove, a condition that also occurs in small individuals of B. devdevi from the upper Irrawaddy River basin. In addition, the ethmoidal furrow is absent in the type material of B. cirrhinoides . This furrow is indistinct or absent in small individuals of B. devdevi from the upper Irrawaddy River basin, but is distinct in large individuals. We have examined the types of B. cirrhinoides , and have determined that they are juveniles of B. devdevi . Consequently, we provisionally agree with Yue (2000) that the upper Irrawaddy River and Red River basin materials are conspecific. Based on the Principle of Priority (Article 23.1 of 1999 edition of the ICZN Code), Labeo devdevi Hora, 1936 , has priority over Sinilabeo cirrhinoides Wu and Lin in Wu et al., 1977 .

Wu and Lin, in Wu et al‘s (1977) book involving a systematic revision of the cyprinid fishes of China, described Sinilabeo tonkensis laticeps , based on only two specimens, 256.0 and 331.0 mm SL, respectively, from the Luosuo Jiang and Mengyang He, two tributaries of the Lancang Jiang (upper Mekong River) basin in Yunnan, southern China. Chen (1987), followed by Chu and Chen (1989) and Yue (2000), regarded it as a full species, but Kottelat (2001a) concluded that S. laticeps is a junior synonym of Labeo lippus , which was simultaneously placed by him in Bangana . Since Kullander et al. (1999) pointed out that Bangana should be treated as feminine, transfer of Labeo lippus to Bangana requires a change in ending of the name lippus to lippa. The same change in species ending is also required for Sinilabeo decorus (now Bangana decora ).

Bangana zhui has long been confused with B. yunnanensis (Wu, Lin, Chen, Chen and He, 1977) , a valid species herein recognized. In 1963, Chu and Wang described Mirolabeo yunnanensis as a new genus and species; however, the name was not available because Chu and Wang’s description was in an unpublished work. Wu et al. (1977) were the first to use the name Sinilabeo yunnanensis for specimens from the upper Mekong River basin and Nanpan Jiang of the upper Zhu Jiang (Pearl River) basin, and gave a detailed description for this species. This makes the species name yunnanensis available according to Article 10.1 of the 1999 ICZN Code, with the formal description of Sinilabeo yunnanensis thus attributed to Wu, Lin, Chen, Chen and He (1977) (Article 50 of 1999 ICZN Code).

The original description of B. yunnanensis by Wu et al. (1977) was based on six syntypes, inlcuding two specimens (IHB 591033-4; 81.6-96.2 mm SL) from the upper Mekong River basin, and four (IHB 65018-21; 221.3-351.2 mm SL) from the Nanpan Jiang of the Pearl River basin. However, these specimens in fact represent two species, of which the real B. yunnanensis is represented by the upper Mekong River basin material, whereas the remaining specimens, from the Nanpan Jiang (see below), are B. zhui . In order to stabilize the name, the larger (96.2 mm SL) of the two specimens (IHB 591033) is here designated as the lectotype of B. yunnanensis . The smaller (81.6 mm SL) specimen (IHB 591034) becomes the paralectotype.

While retaining the name S. yunnanensis for the upper Mekong River basin material, Zheng and Chen (1983) described, as S. zhui , the Nanpan Jiang (in the upper Pearl River basin) specimens. Zhu (1995) did not recognize S. zhui as a valid species, but Yue (2000) used it as a replacement name for S. yunnanensis in her review of Chinese labeonine species. Our observations on the specimens formerly reported as S. yunnanensis or S. zhui show that marked differences exist between the upper Mekong River and the Nanpan Jiang basin forms. These findings confirm that S. zhui is still a valid species, which is here transferred to Bangana .

Based on the above analysis, we have determined that Bangana is represented in China by 13 valid species, the distributions of which may be seen in figure 3. They are: B. decora , known from the Pearl River basin; B. dero from the upper Brahmaputra River basin; B. devdevi from the upper Irrawaddy River and Red River basins; B. discognathoides from Hainan Island; B. lemassoni from the Red River basin; B. lippa from the upper Mekong River basin; B. rendahli from the upper Chang Jiang (Yangtze River) basin; B. tonkinensis from the Red River basin; B. tungting from the middle Yangtze River basin, B. xanthogenys from the Red River basin; B. wui from the Pearl River basin; B. yunnanensis from the upper Mekong River basin; and B. zhui from the upper Pearl River basin. A key to these species is provided below.

Key to Chinese species of Bangana

1a. Postlabial groove interrupted and confined to side of lower jaw.. ...................... 2

1b. Postlabial groove uninterrupted to form a transverse groove separating lower lip from mental region.. ........................................................................................... 8

2a(1a). Mouth opening C-shaped; snout with an ethmoidal furrow; a shallow, transverse fissure bridging postlabial groove and its ounterpart.. ....................................... 3

2b(1a). Mouth opening arch-shaped; snout without an ethmoidal furrow; no shallow, transverse fissure bridging post-labial groove and its counterpart.. ................... 4

3a(2a). 8-9 scale row between lateral line and dorsal-fin origin; 24 circumpeduncular scales .......................................................................................................... B. dero

3b(2a). 5-6 scale row between lateral line and dorsal-fin origin, 20 circumpeduncular scales ..................................................................................................... B. devdevi

4a(2b). Snout with some large tubercles irregularly organized in two or three rows on tip and anterior lachrymal.. ...................................................................................... 5

4b(2b). Snout with numerous tiny tubercles concentrated on tip (these also present in small individuals less than 100 mm).. ................................................................ 7

5a(4a). Belly scales not embedded in skin; pelvic fin reaching beyond anus.. ................. ........................................................................................................... B. lemassoni

5b(4a). Belly scales embedded under skin; pelvic fin not reaching anus.. ..................... 6

6a(5b). 45-47 perforated lateral line scales; 24 circumpeduncular scales. ..... B. rendahli

6b(5b). 42-43 perforated lateral line scales; 20 circumpeduncular scales ....... B. tungting

7a(4b). Dorsal fin with slightly concave distal margin; pelvic fin not reaching anus.. ..... ................................................................................................................ B. decora

7b(4b). Dorsal fin with deeply concave distal margin; pelvic fin reaching beyond anus .. ....................................................................................................... B. xanthogenys

8a(1b). 20 circumpeduncular scales.. .............................................................................. 9

8b(1b). 16 circumpeduncular scales.. ............................................................................ 10

9a(8a). 43-45 perforated lateral line scales; 1-2 scales between anus and anal-fin origin. ........................................................................................................ B. tonkinensis

9b(8a). 39-42 perforated lateral line scales; 3-4 scales between anus and anal-fin origin. .................................................................................................................. B. lippa

10a(8b). 38-45 perforated lateral line scales.. ................................................................ 11

10b(8b). 47-48 perforated lateral line scales.. ................................................................ 12

11a(10a). 38-39 perforated lateral line scales ......................................... B. discognathoides

11b(10a). 41-45 perforated lateral line scales.. .......................................................... B. wui

12a(10a). Body depth 22.7-25.6 % SL; interorbital space 38.5-45.5 % HL ........................ ....................................................................................................... B. yunnanensis

12b(10b). Body depth 21.3-22.2 % SL; interorbital space 55.6-66.7 % HL.. .......... B. zhui