NAT. NAT. HIST. BUL L. SIAM Soc. 46: 105-135 ， 1998 REVIEW OF THE TROPICAL ASIAN CYPRINID FISH GENUS POROPUNTIUS ，WITH DESCRIPTIONS OF NEW SPECIES AND TROPHIC MORPHS η son R. Robertsl ABSTRACT Nominal Nominal species ref ，巴 rable th to 巴町opical Asian barbin cyprinid fish genus Poropuntius Smith ， 1931 (excluding Hypsibarbus Rainboth ， 1996) are reviewed ，and new species described from from the Salween ，Tenasserim ，Me k1 ong ，and Mekong basins. 百le cave fish Barbus speleops Roberts ， 1991 from Th am Phu Keao in Th ailand (Mekong basin) is referred to Poropuntius. At At least two species exhibit discrete trophic polymorphism ，including 出eriverine P. bolo νenensis new new species from streams on the Bolovens Plateau in southem Laos (Mekong basin) with four mo 中hs. Some of 出e 町ophic morphs of Poropuntius have generalized mouths and other trophic S汀uctures ，but others are so modified that that they would be assigned to different genera if they they were distinct species. Trophic polymorphism or phenotypic plasticity of the kind reported here here in Poropuntius is extremely widespread in cyprinoids and may have contributed greatly to to their speciation ，adaptive radiation ，and macroevolution ，including in Lake Lanao (Mindanao) and and Tana Lake (E 由iopia) (Mina ，et al.， 1996; Nagelkirke ，et al.， 1996) as well as over more extensive extensive geographical areas and longer time spans. INTRODUCTION Poropuntius Poropuntius comprises numerous m 巴dium-sized species (mostly 10-20 cm in standard length length as adu It) living mainly in mountain streams at moderate elevations (typically less than than 1，000 m) in mainland Asia ，from Assam and Yunnan to the Malay peninsula. Some lacustrine lacustrine and riverine species are significant ecologically and in artisan a1 wildcapture fisheries. fisheries. A number of the species 紅 e handsomely colored ， but they seldom if ever occur in in the aqu 紅白m trade. The majority have relatively generalized trophic s仕uctures ， with two well-developed pairs of barbels and moderately developed lips and homy jaw sheaths. 百le genus is ve 可 much in need of a comprehensive systematic revision but this is presently thwarted thwarted by paucity of material from many p訂 ts of the genus range ，especially in Assarn and and Yunnan. The present paper is based mainly on specimens collected by the author in areas areas where little or no collecting had been done previously ， but representing less than half the the range of the genus. Thus no freshly collect 巴d material has been exarnined for some of of the nominal species level taxa ，especially those described by Chinese ichthyologists. Some species exhibit substantial phenotypic plasticity in the form of discrete trophic mo 中hs ， which has not been previously reported or recognized as such in the genus. The new Research IResearch Associate ，Smithsonian Tropical Research Institute; Department of Ic hthyology ，Califomia Academy of of Sciences ， San Francisco ，CA 94118 USA Received Received 27 July 1997; accepted 29 March 1998 105 105 106 106 TYSON R. ROBERTS species species Poropuntius bolovenensis is described with fo 町 discrete trophic mo 中 hs having: 1) 1) norm a1 or gener a1 ized mouth ，1ヤ s and jaws (P. bolovenensis bolovenensis); 2) n町 ow head ，sh 紅 p snout ， elongate jaws and thickened lips (P. b. acuticeps); 3) short head and laminar laminar lower horny jaw sheath (P. b. glaridostoma); and 4) 1紅 ge ， broad head and wide jaws (P. b. laticeps). 官lis species and its mo 甲hs apparen t1 y is endemic to 出e Bolovens Plateau ，and may be threatened with extinction by the Xe Nam Noi ・Xe Pian hydropower project. project. h 血is paper intraspecific trophic mo 中hs 紅 'e formally described and named as species- level 住inomin a1 s. Many mo 中hologic a1 1y distinctive cypri 凶d fishes previously named as species species are really intraspecific morphs. Others may be full species ， but their status may never never be resolved because they are now extinct (e.g. the so-c a1 1ed cyprinid “species flock" 泊 Lake Lanao). Non-sexu a1 in 位'aspecific evolutionary divergence ，which may prime sympa 凶 c as well as a1 10pa 凶c speciation ， is gaining acceptance as am 司jor factor in mo 中hologic a1 dive 培ence ，speciation ，組 d generation ofbiodiversity (see WEST-EBE 周iARO， 1986; 1986; 1989; MEYER ， 1993; SMITH & SKULASON ，1996 ，and references cited 白erein). 百le sort sort of intraspecific trophic polymorphism reported here for P. bolovenensis ， in many instances instances with even greater differences among morphs ， occurs in many genera of the cyprinid cyprinid subfarnily Barbinae as we l1 as in some Schizothoracinae 佃 d Leuciscinae. The genetic genetic basis for such polymo 甲hism probably w 俗 present in the earliest cyprinoids ， or developed developed soon after 血eir divergence from other Ostariophys i. It eviden t1 y has played a major major role in their stunning adaptive radiation and dominance in temperate as well 邸 tropic a1 continen ta1 f詑sh waters ，especi al1 y in Asia. In modern faunas 仕lis ancient assortment of of genetic a1 1y-de 回 mined phenotypic differences is expr ，邸 sed 儲 in 回 specific morphs mainly 泊 species occupying lakes or streams on plateaus at higher elevations isolated by barriers such such as waterf a1 1s (as in Poropuntius bolovenensis on 出e Bolovens Plateau). Species not exhibiting exhibiting such morphs in their phenotypes may nevertheless c紅 ry al1 of the information 泊 their genome n民 essary to generate an array of discrete phenotypes. Ec ologic a1 conditions (in c1 uding biodiversity of food organisms and other fish species in 血e same habitat) may determine determine whether selection favors a phenotypically monomorphic or polymophic species. A larninar lower horny jaw shea 白 (as in P. b. glaridostoma) is one of the most 企'equen t1 y recurring 阻 d evolutionarily significant jaw 町田知res in Cyprinidae. It s presence often often involves a major dietary shift ， such as 企om feeding on insects or higher plants to feeding feeding on a1 gae 組 d associated org 白山ms which must be scraped 企om filamentous or gelatinous gelatinous mats. 百le genetic basis for shifting from an unculiferous or otherwise non- larninar larninar lower jaw sheath to a1 包凶nar shea 血 probably evolved very early in cyprinid evolution ， perhaps before divergence of Barbinae and Leuciscinae ，and perhaps evolved only only once. 百le larninar jaw shea 由 itself may be modified 泊 shape ，width ， hardness and other other characters to give rise to more 出an one in 回 specific trophic mo 中h. Di stinctive mo 中hs may evolve into full-fledged species or genera by speciation (whether a1 10pa 凶 c or sympa 凶 c) ，and by subsequent linear evolution or orthogenesis 凶 o separate genera. Monomorphic cypri 凶d genera with laminar horny jaw sheaths which may have evolved in in this fashion include but are not limited to Capoeta ，Cyprinion ，Onychostoma ， Scaphiodonichthys ，Semiplotus ， Varicorhinus. Highly specialized cyprinid genera characterized characterized by extremely broad or extremely n町 ow lower jaws typic a1 1y have laminar lower lower jaw sheaths. CYPRINID FISH GENUS POROPUNTIUS 107 The systematic portion of this paper is divided into two sections. In the first section all all of the nominal species known to me 出at are referable to Poropuntius (sensu Rainboth ， 1996a ，b) ， are listed in chronological order of their description beginning with P. deauratus (Valenciennes ，1842) ， the earliest described species. Some of these species are known only only from their original descriptions in Chinese. Most of them are probably valid species. The Th ai cavefish Barbus speleops Roberts 1991 is referred to Poropuntius. Puntius tawarensis tawarensis Weber and de Beaufort ，1916 ，is retained in Poropuntius following KoπELAT (1 989) but probably belongs elsewhere. The s巴cond section is devoted to descriptions of new speci 邸姐d of 住ophic mo 中hs. Materials.-Specimens Materials.-Specimens reported on in this paper are deposited in the fish collections of of the following institutions: ANSP ，Academy of Natural Sciences ，Philadelphia; CAS ， California California Academy of Sciences ，San Francisco; KlZ， Institute of Zo ology ， Chinese Academy of of Sciences ，Kunming; MCSNG ，Museo Civico di Storia Naturale ，Genoa; 阻沼町， Museum National National d' Histoire Naturelle ，Paris; TISTR ， Thailand Institute for Technical and Scientific Research ，B 組 gkok; USNM ， National Museum of Natural History ，Washington ， D.C.; and WIH ，Institute of Hydrobiology ， Chinese Academy of Sciences ，Wuhan. Poropuntius Poropuntius Smith ， 1931 Poropuntius Poropuntius Smith ， 1931: 14 (勿 pe species by monotypy Poropuntius normani Smith ， 1931). 1931). Comparative Comparative osteological and other anatomical studies that might provide distinguishing characters characters for generic placement of the two dozen or more known species of Poropuntius and hundreds of other sp 巴cies of Asian barbine cyprinids remain largely undone. At present ， Poropuntius is definable mainly by characters present in many unrelated cyprinid species. species. Thus the last simple dorsal fin ray invariably is strongly serrated ，and dorsal fin soft soft rays almost invariably 紅巳 8 (or 8 11z). The main exception is the species Poropuntius bolovenensis ， in which a few specimens hav 巴 6 11z or 7 (or 7 11z). Most species have two pairs pairs of well developed barbels ，rostral and maxillary ， but some species have small maxill 訂 y barbels barbels only and one has no barbels. Mouth form tends to be generalized in species with well well developed barbels ， but at least two species have 住ophic mo 甲 hs with very different oral oral mo 中 hology. Some species with reduced barbels have reduced lower lips ， with trenchant cutting cutting edge on a broad ，homy lower jaw sheath. None of the species has a median chin barbel" “barbel" or mental lobe (mentum) like that in species of Tor ，Folifer ，and Parator. Pharyngeal Pharyngeal teeth have only been examined or reported on in a few species; these have three three rows with counts of 2，3 ，5.