Cypriniform Species Research Articles

Origin, development, function, and evolution of cypriniform trophic novelties

Cypriniform fishes are characterized by a number of evolutionary trophic novelties. These feeding novelties have allowed cypriniforms to take full advantage of a number of unique trophic niches. One such feeding innovation, the palatal organ, is a complex muscular structure located on the pharyngeal roof of cypriniform fishes. The palatal organ is a dorsal mass of complexly arranged muscle fibers within the buccopharyngeal cavity innervated by the vagal lobe and covered by a taste bud coated epithelium. Here we use developmental data from zebrafish, functional data from carp and goldfish, and histological data and modeling approaches from assorted cypriniform species to address how the palatal organ developed and explain some of its functional evolution. Using zebrafish we first describe the origin and ontogenetic development of the palatal organ. Comparative data on histological structure and myosin composition of the palatal organ across a wide phylogenetic sampling of cypriniforms is then used to determine the variation in structure and potential function of the palatal organ across Cypriniformes. The general assumption has been that the function of the palatal organ is conserved across cypriniforms, and requires the careful sensory control made possible by a hypertrophied vagal lobe to function properly. Few have considered the possibility that the palatal organ may have become adapted for different functions during the course of cypriniform evolution. Its possible role in other feeding modes has been largely overlooked as it has been presumed that the palatal organ's only function is in sorting during benthic feeding events. Using electromyography and high‐speed video to examine palatal organ activity in the common carp and goldfish, muscle activation patterns demonstrate that the palatal organ is likely employed just prior to suction generation, during suction feeding behaviors, during prey processing events, and may even play a role in respiration during stressful conditions. Furthermore, the palatal organ shows behavioral modulation when different food types and positions are used. These data suggest that the palatal organ is a multi‐functional structure with a much wider range of functional repertoires than previously shown. While sorting during benthic feeding may have been the primitive function of the palatal organ, it has likely been secondarily adapted for increasing dietary breadth during the course of cypriniform evolution. This muscular pad has become secondarily modified for different forms of feeding but may even play a more generalized role in suction feeding and prey processing within cypriniforms.

Phylogenetic relationships of Acheilognathidae (Cypriniformes: Cyprinoidea) as revealed from evidence of both nuclear and mitochondrial gene sequence variation: Evidence for necessary taxonomic revision in the family and the identification of cryptic species

Bitterlings are relatively small cypriniform species and extremely interesting evolutionarily due to their unusual reproductive behaviors and their coevolutionary relationships with freshwater mussels. As a group, they have attracted a great deal of attention in biological studies. Understanding the origin and evolution of their mating system demands a well-corroborated hypothesis of their evolutionary relationships. In this study, we provide the most comprehensive phylogenetic reconstruction of species relationships of the group based on partitioned maximum likelihood and Bayesian methods using DNA sequence variation of nuclear and mitochondrial genes on 41 species, several subspecies and three undescribed species. Our findings support the monophyly of the Acheilognathidae. Two of the three currently recognized genera are not monophyletic and the family can be subdivided into six clades. These clades are further regarded as genera based on both their phylogenetic relationships and a reappraisal of morphological characters. We present a revised classification for the Acheilognathidae with five genera/lineages: Rhodeus, Acheilognathus (new constitution), Tanakia (new constitution), Paratanakia gen. nov., and Pseudorhodeus gen. nov. and an unnamed clade containing five species currently referred to as “Acheilognathus”. Gene trees of several bitterling species indicate that the taxa are not monophyletic. This result highlights a potentially dramatic underestimation of species diversity in this family. Using our new phylogenetic framework, we discuss the evolution of the Acheilognathidae relative to classification, taxonomy and biogeography.

DNA barcoding application of mitochondrial COI gene sequence in medicinal fish of Culter (Pisces: Cyprinidae)

The sequence variation of medicinal fish of Culter (Pisces: Cyprinidae) was analyzed by using cytochrome c oxidase subunit I (COI) sequencing collected from different regions of the Yangtze River basin, and we examine whether barcoding of COI can be used to discriminate medicinal fish of Culter. The AT content in the COI region of medicinal fish of Culter was higher than that of GC, which was similar with other species of Cypriniformes. Ninty-six percent of nucleotide changes were observed at the 3rd codon position of COI sequence, but the amino acid compositions translated by COI sequences of all Culter fish stayed the same. It is suggested that most synonymous mutations might occur at the 3rd position. The average Kimura-2-parameter (K2P) distance within-species was lower than 1%, and the K2P distance of pairwise-species was 10 times as much as that of within-species. The phylogenetic tree estimated by Neighbour-joining method indicated that species within genera invariably clustered, and generally so did individuals within species. Individuals from operational taxonomic units designated as different Culter species, supporting morphological evidence for each of these being separate species. It is suggested that the COI barcoding can be used to identify medicinal fish species of Culter.

Habitat variation and invasive species as factors influencing the distribution of native fishes in the lower Fraser River Valley, British Columbia, with an emphasis on brassy minnow (Hybognathus hankinsoni)

Brassy minnow (Hybognathus hankinsoni Hubbs, 1929) have disjunct distributions in western Canada, making them a species of conservation concern. We assessed changes in the distribution of invasive species as factors influencing the distribution of brassy minnow and other native species by comparing historical and current distributions in the lower Fraser River in British Columbia. We tested effects of physical habitat parameters on local distributions of brassy minnow and for evidence of negative interactions between brassy minnow and invasive brown bullhead (Ameiurus nebulosus (Lesueur, 1819)). Comparison of contemporary and historical (1956 and 1959) fish distributions indicated significant declines in native cypriniform (minnows and suckers) species, including brassy minnow, but no change in the number of invasive species, although there was some faunal turnover. Logistic regression suggested that conductivity, turbidity, and water temperature were important predictors of brassy minnow presence. Appearances of adult-sized brown bullhead at one site corresponded with reduced abundance of native fishes. In growth experiments with brassy minnow, brown bullhead, and redside shiner (Richardsonius balteatus (Richardson, 1836)), brassy minnow exhibited mass loss and mortalities, suggesting that they were poor competitors. Our results contribute to a better understanding of abiotic and biotic factors affecting distribution and persistence of brassy minnow.

Fish Species Diversity of Nagaram Tank of Warangal, Andhra Pradesh

The fish production plays a significant role in the human economy. India has vast potential for development of inland fisheries. In the present study an attempt has been made to evaluate the physico-chemical characteristic features and fish fauna diversity of Nagaram tank, located at sub urban of Warangal. It proposed to enhancement of fish production in a sub urban perennial water body in Warangal district of Andhra Pradesh. The study was conducted during June 2007 to May 2010. The study revealed that different regions of the tank receive variable precipitation and hence meteorological factors governing the physico-chemical properties of the tank which in turn influence planktonic diversity and so that all the physico-chemical and biological factors have direct influence on the fish production. From the present study, it observed that all the physico-chemical parameters are at nearly permissible limit at all the 4 identified stations. It is estimated that the fish fauna of Nagaram tank consists of 30 species belonging to 13 families. Among the collections 13 species of Cypriniformes, order Siluriformes consists of 7 species, Channiformes consists of 03 species, Perciformes 05 species, Osteoglossiformes 01 and order Atheriniformes consists of one species. Therefore, it is suggested that the immediate measures may be taken to avoid further contamination of this tank which has been started contaminated due to anthropological activities. Finally it may be concluded that the Nagaram tank is rich in fish diversity and is still in a position to set a good example of conservation of native fish fauna by the sustainable management practices.

Cypriniformes of Borneo (Actinopterygii, Otophysi): An Extraordinary Fauna for Integrated Studies on Diversity, Systematics, Evolution, Ecology, and Conservation

Borneo Island is governed by the countries of Brunei Darussalam, Malaysia (Sabah and Sarawak) and Indonesia(Kalimantan) and is part of Sundaland. These countries have a high diversity of freshwater fishes, especially describedand undescribed species of Cypriniformes; together these species and other flora and fauna represent an extraordinaryopportunity for worldwide collaboration to investigate the biodiversity, conservation, management and evolution ofBorneo’s wildlife. Much of the fauna and flora of Borneo is under significant threat, warranting an immediate and swiftinternational collaboration to rapidly inventory, describe, and conserve the diversity. The Sunda drainage appears to havebeen an important evolutionary centre for many fish groups, including cypriniforms (Cyprinidae, Balitoridae andGyrinocheilidae); however, Northwestern Borneo (Brunei, Sabah and Sarawak) is not connected to Sundaland, and thisdisjunction likely explains the non-homogeneity of Bornean ichthyofauna. A previous study confirmed that northernBorneo, eastern Borneo and Sarawak shared a similar ichthyofauna, findings that support the general hypothesis forfreshwater connections at one time between western Borneo and central Sumatra, and south Borneo and Java island.Borneo is drained by five major rivers: (1) Rajang and Baram rivers in Sarawak, and (2) Kapuas, Mahakam and Baritorivers in Kalimantan. The Cypriniformes is the most diverse clade in Borneo, and it is represented by at least 285 speciesin 55 genera and eight major clades (Balitoridae, Cobitidae, Cyprinidae, Gyrinocheilidae, Leptobarbidae, rasborines,cultrines and Paedocyprididae); at least 147 (52%) of these species are endemic to the incredibly diverse habitats ofBorneo. Most fish faunal studies in Borneo have involved inventory and discovery; however, none to date have focusedtheir efforts on the great biodiversity and systematics of Cypriniformes. In this paper we briefly discuss the generalbiodiversity of cypriniforms in Borneo, including recent revisions to the classification of the order through theCypriniformes Tree of Life and Planetary Biodiversity Inventory efforts supported by the USA NSF basic scienceinitiatives, in conjunction with researchers in countries of Borneo. It is our hope that this particular summary willgalvanize individuals to increase worldwide collaborative and integrated efforts on the biodiversity of Cypriniformes,and incite lively discussions among a broad array of interested parties, including those involved in the recent and critically important “Heart of Borneo” initiative funded by all these countries and some NGOs.

Molecular systematics of western North American cyprinids (Cypriniformes: Cyprinidae)

The phylogenetic or evolutionary relationships of species of Cypriniformes, as well as their classification, is in a era offlux. For the first time ever, the Order, and constituent Families are being examined for relationships within aphylogenetic context. Relevant findings as to sister-group relationships are largely being inferred from analyses of bothmitochondrial and nuclear DNA sequences. Like the vast majority of Cypriniformes, due to an overall lack of anyphylogenetic investigation of these fishes since Hennig’s transformation of the discipline, changes in hypotheses ofrelationships and a natural classification of the species should not be of surprise to anyone. Basically, for most taxa noproperly supported phylogenetic hypothesis has ever been done; and this includes relationships with reasonable taxonand character sampling of even families and subfamilies. As such, like others, many western North American cyprinidgenera have had a controversial taxonomic and systematic history.Our effort to better understand the evolutionary history of this artificial geographic grouping of species (Western)surveyed taxa and characters broadly. We analyzed 127 taxa (71 species) from 36 genera, including representative taxafrom all 22 western genera hypothesized to form the Western Clade sensu Coburn and Cavender (1992). Our evaluationalso included additional sampling from a heterogeneous array of species from the western genera Algansea, Gila,Lepidomeda, Ptychocheilus and Siphateles. Resulting phylogenetic inferences, based on one mitochondrial and threenuclear genes (mtDNA: cytb; nDNA: Rag1, Rhod, S7), consistently resolved a well-supported Western Clade, but oneinclusive of Chrosomus erythrogaster. This taxon, always formed the sister group to the extant species of Gila plus 10other western genera. Our Western Clade is qualitatively different from that of prior studies and does not include thegenera Agosia, Algansea, Iotichthys, Lepidomeda, Meda, Mylocheilus, Plagopterus, Pogonichthys, Rhinichthys, Tiarogaor Yuriria. All of these taxa were, however, included in Coburn and Cavender´s (1992) Western Clade. Our broader-scalesurvey and increased character sampling were always resolved these latter taxa within one of two different major clades:the OPM Clade (sensu Mayden 1989) and the Creek Chub—Plagopterin Clade (sensu Simons et al. 2003). Ourhypothesized Western Clade places Orthodon sister to a Western Chub-Pikeminnow Clade also inclusive of Acrocheilus,Eremichthys, Gila, Hesperoleucus, Lavinia, Moapa, Mylopharodon, Ptychocheilus, Relictus and Siphateles. The lattertaxa have traditionally been recognized at the generic level, simply on the basis of their morphological distinctivenessand not on the basis of a phylogenetic evaluation of relationships. Composition of our Western Chub-Pikeminnow Cladealso reveals genetic divergences between species of some genera (Gila, Ptychocheilus, Siphateles) comparable to geneticdivergences documented between genera within the Western Clade. Relationships for these 10 genera also highlighttaxonomic inconsistencies relative to recent phylogenetic analysis and, in some cases, are in need of focused attentionusing morphology or additional molecular data to test relationships that will eventually establish a stable classification.Some of these genera are clearly unnatural relative to other genera and their classification or ranking is an obligatory change in modern science of phylogenetics.

Phylogenetic placements of the barbin genera Discherodontus, Chagunius, and Hypselobarbus in the subfamily Cyprininae (Teleostei: Cypriniformes) and their relationships with other barbins

The barbin genera Discherodontus Rainboth 1989, Chagunius Smith 1938 and Hypselobarbus Bleeker 1860 are distrib-uted in Southeast and South Asia and are among the least studied taxa of the order Cypriniformes. Few morphologicalstudies have been conducted on these genera and only a very limited number of morphological characters were employedto hypothesize or infer their monophyly, inter-relationships, and relationships with other barbins. The main aim of thisstudy is to examine the monophyly of these three genera and propose hypothesis of relationship among these taxa andother barbins based on a molecular phylogeny of the subfamily Cyprininae. A total of 106 cypriniform species were sam-pled, including 64 species and 31 genera of barbins collected from Eurasia and Africa. Partitioned maximum likelihoodanalysis was performed using DNA sequences derived from five mitochondrial genes (5601 bp): cytochrome c oxidasesubunit I (COI), cytochrome b (Cyt b), 16S ribosomal RNA (16S), NADH dehydrogenase subunits 4 (ND4) and subunits5 (ND5). The resulting phylogeny demonstrates that, under current taxon sampling, Discherodontus, Chagunius, andHypselobarbus are all monophyletic genera. Together they do not form a monophyletic group, as hypothesized in previousstudies, but are instead part of three distinct and unrelated clades. Discherodontus constitutes the basal lineage of a cladeformed by Southeast Asian barbins (e.g. Poropuntius, Hypsibarbus, Balantiocheilos); Chagunius is basal to a cladeformed mainly by Puntius and allies (although this relationship was only weakly supported); Hypselobarbus and Barbuscarnaticus formed a clade sister to a clade including Tor, Neolissochilus, Labeobarbus, and Varicorhinus. Homoplasy andshared plesiomorphy of some hypothesized important morphological characters employed in previous studies that led researchers to hypothesize earlier relationships are discussed.

Papers supported by the All Cypriniformes Species Inventory Project (ACSII) including those presented at the International Conference inChiang Mai, Thailand, 13–16 January 2012 (COVER)

(COVER)

Fishes of Inland Waters of the Phu Quoc Island, Gulf of Thailand, Vietnam: Ichthyofauna Structure and Some Remarks on the Majorevolutionary Trends in its Genesis

Background. The ichthyofauna of the Phu Quoc Island (Vietnam), situated in the Gulf of Thailand in the proximity of the coastline of Cambodia, has not been sufficiently studied. The isolation of the island combined with the knowledge on its geological history could yield conclusions on the evolutionary trends and speculations on how individual faunistic groups were formed. The aims of this study were to investigate the recent ichthyofauna of the Phu Quoc Island and to analyze the major evolutionary trends in its history by a comparison with recent faunas of the neighbouring mainland. Materials and methods. A total of about 4000 fishes representing 97 different teleostean species were collected at 46 sampled sites in the Phu Quoc Island from 6 December 2011 to 12 January 2012 by using different kinds of sampling equipment and collection methods as well as through exploring different habitats. Verification of field species identification and further morphological studies were based on 1290 specimens. Results. The list of fishes collected in inland waters of the Phu Quoc Island includes 97 species representing 13 orders and 39 families of teleostean species. The majority of these species correspond to the main diagnostic characters of known valid taxa. Two species (Kryptopterus bicirrhis and Brachygobius doriae) demonstrate some differences from their previously recorded diagnostic features, and two cypriniform species significantly differ from their valid congeners and should be described as new taxa. Conclusion. The major trends in the history of the ichthyofauna of Phu Quoc Island were the elimination of true freshwater stenobiontic species and the progressive development of euryhaline and eurytropic species which replaced former species in seasonally variable biotopes of relatively small tropic island. These eurytropic species are characterized by rather wide morphometric variability and do not demonstrate significant differences in their diagnostic characters comparing the island- and the mainland populations. Two species evolved into separate new taxa during the about 10 000 year time interval of the fauna’ isolation are characterized by the only common feature—belonging to small short-lived species. As such they were more prone to faster evolutionary changes and the pace of the speciation process. The evolutionary process in fish of the Phu Quoc Island was characterized by weak founder effect and weakly pronounced disruptive selection—producing a low number of evolved species.

Study on fish fauna diversity of Bung Binh Thien wetland, An Giang province

Bung Binh Thien belongs to the An Phu district, An Giang province, there were 111 fish species belonging to 27 families in 10 orders. Of the total species collected, there were 44 species of Cypriniformes or 44.39%; the order Siluriformes comprised 29 species or 26.23%; the order Perciformes 19 species or 19.17%; the order Synbranchiformes 7 species or 7.60%; the other orders comprise fewer numbers of species or percentage of total. There are 6 threatened species listed in the Red Book of Vietnam, 2007, and Red list of IUCN. The model fishery co-management at Bung Binh Thien wetland area seemed to respond to climate change and development of fish resources.

Infection situatus of parasites in freshwater fishs collected in Lam river, Do Luong district, Nghe An province

The results obtained from our research about the parasitic worm, which parasitized freshwater fishs of Lam river (Do Luong district, Nghe An province) provide us the basic knowledge about parasites of freshwater fishs in North Central Vietnam. Total 217 individuals of freshwater fish were carried out an autopsy for checking fish parasites. Among them, 118 fishes (occupied 54.4% total number of surgical fish) belonged to 13 species of Cypriniformes (occupied 54.2% total number of fish species). Of the total 832 samples of fish parasites collected, there were 504 samples of Monogenea, 212 Trematodes, 25 Cestodes, 16 Acanthocephala, 44 Nematoda and 31 Copepoda. Infected rate of fish in study site was not too high, the prevalence was 39.2%. and the density of parasites per each infected host was 9,8 individuals/host. Monogenea was the highest infected group (26.3%), while other groups were lower: from 1.4% to 7.4%. The infected rate was highest in cranoglanis 90%, the next was hemicultus 54.5%, tilapia 50%, red - eyed carp and major carp 40%, mudfish 28.0%. In case of 14 fish species, with 10 surgical fish individuals, the infection rate fluctuated between 16.7% and 90%. The infected rate was observed as the highest in Cranoglanis sinensis (90%) and the lowest in Tilapia (16.7%). Parasite infection intensity in not too high, one individual of fish infected with 9.8 worms in average (min - max: 1 - 84). The highest infected intensity was found in common carp 33.0 worms/fish (1 - 64), the next is red - eyed carp 29.0worm/fish and cranoglanis 13.9worms/fish; the lowest infection intensity was found in hemicultur 12.3 worms/fish. The certain host are normally infected with 2 or 3 parasite groups their prevalence and density is not too high.

Comparative kinematics of cypriniform premaxillary protrusion

Premaxillary protrusion has evolved multiple times within teleosts, and has been implicated as contributing to the evolutionary success of clades bearing this adaptation. Cypriniform fishes protrude the jaws via the kinethmoid, a median sesamoid bone that is a synapomorphy for the order. Using five cypriniform species, we provide the first comparative kinematic study of jaw protrusion in this speciose order. Our goals were to compare jaw protrusion in cypriniforms to that in other clades that independently evolved upper jaw protrusion, assess the variation in feeding kinematics among members of the order, and test if variation in the shape of the kinethmoid has an effect on either jaw kinematics or the degree of suction or ram used during a feeding event. We also examined the coordination in the relative timings of upper and lower jaw movements to gain insight on the cypriniform protrusile mechanism. Overall, speed of protrusion in cypriniforms is slower than in other teleosts. Protrusion speed differed significantly among cypriniforms but this is likely not due to kinethmoid shape alone; rather, it may be a result of both kinethmoid shape and branching patterns of the A1 division of the adductor mandibulae. In the benthic cypriniforms investigated here, upper jaw protrusion contributed up to 60% of overall ram of the strikes and interestingly, these species also produced the most suction. There is relatively little coordination of upper and lower jaw movements in cypriniforms, suggesting that previous hypotheses of premaxillary protrusion via lower jaw depression are not supported within Cypriniformes. Significant variation in kinematics suggests that cypriniforms may have the ability to modulate feeding, which could be an advantage if presented with the challenge of feeding on different types of prey.

Modulation of warm-temperature-acclimation-associated 65-kDa protein genes (Wap65-1 and Wap65-2) in mud loach (Misgurnus mizolepis, Cypriniformes) liver in response to different stimulatory treatments

Two paralogous isoform cDNAs of warm-temperature-acclimation-associated 65-kDa protein (Wap65-1 and Wap65-2) were isolated from the cypriniform species, mud loach (Misgurnus mizolepis), and characterized. The deduced amino acid sequences of the two mud loach Wap65 isoforms (mlWap65-1 and mlWap65-2) share moderate levels of sequence homology with their corresponding orthologues from teleosts and with human hemopexin, a possible mammalian homologue. Both isoforms display conserved features, including essential motifs and/or residues that are important for the protein structure of hemopexin. In overall, mlWap65-2 is more homologous to human hemopexin than is mlWap65-1. Both mud loach Wap65 transcripts are predominantly expressed in liver, although the transcripts are ubiquitously detectable in most tissues with variable basal expression. Both mlWap65 isoforms are differentially regulated during embryonic development, and the changes in transcript levels during embryogenesis are greater for mlWap65-2 than for mlWap65-1. The transcription of the mlWap65 genes is differentially modulated by various stimuli, including thermal changes, immune challenge (lipopolysaccharide injection or bacterial infection), and heavy metal exposure (cadmium, copper, or nickel). The isoform mlWap65-1 is more responsive to warm temperature treatments than mlWap65-2, whereas mlWap65-2 is much more strongly stimulated by immune and heavy metal challenges than is mlWap65-1. Taken together, the results of this study suggest that mud loach Wap65 isoforms are potentially involved in multiple cellular pathways and that the two mud loach Wap65 isoforms undergo functional partitioning or subfunctionalization.

Gill arch and hyoid arch diversity and cypriniform phylogeny: Distributed integration of morphology and web-based tools

Using the multiple tools available to support an online collaborative environment, we surveyed 62 morphological features from the hyoid arch and gill arches of 53 species of cypriniform fishes that matched those sampled in recent molecularanalyses and two sets of outgroup species (‘Saitoh outgroups’ and ‘Basal outgroups’). This is a skeletal region whose variation is considered historically significant within fishes and Cypriniformes in particular, and we review previous work in light of our own. The clarity of description of characters was enhanced by the use of a community reference ontology, the Teleost Anatomy Ontology. Terms, synonyms, and definitions for skeletal features from this region were contributed to this ontology, and links to these terms and relationships are included in our character descriptions. One thousand two hundred sixty-three images of features from this region were linked to ontology terms and deposited in a community image repository, Morphbank; these are linked to the characters described herein. Character data were analyzed using parsimony and Bayesian methods for two sets of outgroups, one of which matched that used in previous molecular analyses. The parsimony results, using either outgroup set, indicated similar higher-level relationships, including a sister group relationship between cyprinids and loaches. A basal trichotomy among Gyrinocheilus, catostomids and cyprinids + loaches was the result of Saitoh outgroup analysis in contrast to a sister group relationship between Gyrinocheilus and catostomids discovered in the Basal outgroup analysis. Interestingly, analyses including basal outgroups recovered a monophyletic Cyprinidae, consistent with all previous studies. Character evolution that supports higher-level nodes of interest in the consensus tree is described. In some respects, it might be a surprise that 62 morphological characters from a small skeletal region for only 53 cypriniform species (out of over 3,200 total species) could provide as much resolution as it does. We expect, however, further phylogenetic resolution as morphological data from across skeleton regions are combined, species sampling is increased, and molecular data are added.

Isolation, sequence analysis, and characterization of androgen receptor in Southern catfish, Silurus meridionalis

Androgen receptor (AR), the mediator of androgen, plays important roles in the androgen signal pathway. In the present study, we isolated and analyzed the cDNA sequence and tissue distribution of androgen receptor in Southern catfish (scAR). The full-length cDNA of scAR contains 3,116 bp with an open reading frame (ORF) of 2,415 bp, encoding a protein of 804 amino acids (aa). Tissue distribution analysis of scAR revealed that it was expressed in all tissues examined, with no sexual dimorphism in the ovary and testis. Phylogenetic analysis and multiple amino acids sequence alignment indicated the close relationship and high similarity of scAR with ARs from cypriniform species. In addition, partial sequences of ARs from 7 other siluriform species were also isolated. Comparison of catfish ARs with those from other vertebrates revealed that an extra C-terminal tail of about 20aa exists in all the ARs from siluriform fishes investigated, but not in other ARs. The extra sequence was resulted from a 4-bp insertion before the stop codon of other vertebrate ARs, and it was identical in ARs from siluriform species of the same genus but different among ARs from species of different genera. We report here for the first time that the ARs from siluriform species are longer in C-terminal than those from other vertebrates and it might be useful in reconstruction of the phylogenetic relationship among siluriform fishes. The significance of the extra C-terminal tail for AR function remains elusive.

Evolutionary Trends of the Pharyngeal Dentition in Cypriniformes (Actinopterygii: Ostariophysi)

BackgroundThe fish order Cypriniformes is one of the most diverse ray-finned fish groups in the world with more than 3000 recognized species. Cypriniformes are characterized by a striking distribution of their dentition: namely the absence of oral teeth and presence of pharyngeal teeth on the last gill arch (fifth ceratobranchial). Despite this limited localisation, the diversity of tooth patterns in Cypriniformes is astonishing. Here we provide a further description of this diversity using X-ray microtomography and we map the resulting dental characters on a phylogenetic tree to explore evolutionary trends.ResultsWe performed a pilot survey of dental formulae and individual tooth shapes in 34 adult species of Cypriniformes by X-ray microtomography (using either conventional X-ray machine, or synchrotron microtomography when necessary) or by dissecting. By mapping morphological results in a phylogenetic tree, it emerges that the two super-families Cobitoidea and Cyprinoidea have followed two distinct evolutionary pathways. Furthermore, our analysis supports the hypothesis of a three-row dentition as ancestral for Cyprinoidea and a general trend in tooth row reduction in most derived lineages. Yet, this general scheme must be considered with caution as several events of tooth row gain and loss have occurred during evolutionary history of Cyprinoidea.SignificanceDentition diversity in Cypriniformes constitutes an excellent model to study the evolution of complex morphological structures. This morphological survey clearly advocates for extending the use of X-ray microtomography to study tooth morphology in Cypriniformes. Yet, our survey also underlines that improved knowledge of Cypriniformes life traits, such as feeding habits, is required as current knowledge is not sufficient to conclude on the link between diet and dental morphology.

Number and Distribution of Superficial Neuromasts in Twelve Common European Cypriniform Fishes and Their Relationship to Habitat Occurrence

AbstractThis paper gives the first detailed data on the number and body part related distribution of superficial neuromasts in twelve common European Cypriniform species and examines whether such anatomical variables can be related to rough scale habitat occurrence. The fishes (Barbatula barbatula, Barbus barbus, Chondrostoma nasus, Cobitis taenia, Leuciscus cephalus, Leuciscus leuciscus, Phoxinus phoxinus, Rutilus rutilus, Rhodeus sericeus, Scardinius erythrophthalmus, Tinca tinca, Vimba vimba) were classified in two generalized ‘ecological guilds’, 1) rheophilic and 2) limnophilic or indifferent, based on literature data. The total number of superficial neuromasts was consistent within each species, but differed considerably between species. Lowest numbers of superficial neuromasts were found in Barbatula barbatula (21 ± 4.9 superficial neuromasts per cm body length) (mean ± SD), highest numbers in Vimba vimba (233 ± 36.1). Both species can be classified as rheophilic. Over all no relationship was found between the total number of superficial neuromasts and large scale habitat occurrence. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Diagnostic PCR to identify five rare species of Cypriniformes in China

The major problem that fisheries managers face when trying to enforce the law is identifying fish species. This problem is even worse when it comes to identifying eggs, larvae, bloodstains, scales, mucous stains, and mixtures of these in markets, restaurants and fishing areas. To assist in the acquisition of urgently needed conservation and management data on rare and endangered fish catch and sale, we have developed and tested a highly streamlined molecular genetic approach to identify Cypriniformes fish species. We used species-specific primers and species-specific ladders in a seven-primer multiplex polymerase chain reaction format based on DNA sequence differences among species in the nuclear ribosomal second internal transcribed spacer (ITS2) to discriminate simultaneously among five rare and endangered Cypriniformes species in China. This technique distinguished samples with 100% accuracy. This genetic approach will be useful for the assessment, management and conservation of fish.

Composition and Status of Fishes of Nanla River in Xishuangbanna, Yunnan, China

Field surveys of Nanla River, located on the southwest border between China and Myanmar, were conducted in January and from May to June of 2008. Based on field surveys and historical records, there are a total of 42 species belonging to 4 orders, 14 families, and 34 genera in Nanla River. The species of Cypriniformes are dominant, including 27 species, accounting for 64.3% of the total number of species. Siluriformes and Perciformes both have 6 species, accounting for 14.3% of the total. The number of species of Synbranchiformes is 2, 4.8% of the total. Hemibagrus wyckioides is listed in the China Species Red List. Pangasius sanitwangsei , with a suspected distribution through the Nanla River, is listed in the China Red Data Book of Endangered Animals and China Species Red List. Fish fauna taxa of the Nanla River is dominated by 'old Tertiary groups', which mainly occur in tropical rivers and flood plains, and is the typical group of fishes in tropical Southeast Asia. Based on the ecology type, bottom-dwelling and omnivorous fishes are dominant. Finally, the causes for the listed statuses are briefly summarized as water pollution, overfishing and impacts of introduced species.