Molecular phylogenetic relationships of Eastern Asian Cyprinidae (Pisces: Cypriniformes) inferred from cytochrome <Emphasis Type="Italic">b</Emphasis> sequences

Complete mitochondrial cytochrome b sequences of 54 species, including 18 newly sequenced, were analyzed to infer the phylogenetic relationships within the family Cyprinidae in East Asia. Phylogenetic trees were generated using various tree-building methods, including Neighbor-joining (NJ), Maximum Parsimony (MP) and Maximum Likelihood (ML) methods, with Myxocyprinus asiaticus (family Catostomidae) as the designated outgroup. The results from NJ and ML methods were mostly similar, supporting some existing subfamilies within Cyprinidae as monophyletic, such as Cultrinae, Xenocyprinae and Gobioninae (including Gobiobotinae). However, genera within the subfamily “Danioninae” did not form a monophyletic group. The subfamily Leuciscinae was divided into two unrelated groups: the “Leuciscinae” in East Asia forming as a monophyletic group together with Cultrinae and Xenocyprinae, while the Leuciscinae in Europe, Siberia, and North America as another monophyletic group. The monophyly of subfamily Cyprininae sensu Howes was supported by NJ and ML trees and is basal in the tree. The position of Acheilognathinae, a widely accepted monophyletic group represented by Rhodeus sericeus, was not resolved.     

Evolution and trans-species polymorphism of MHC class IIbeta genes in cyprinid fish

The polymorphism of DAB genes encoding MHC IIbeta was investigated in 11 cyprinid species from central Europe. The species belonged to four subfamilies: Cyprininae, Tincinae, Gobioninae and Leuciscinae. Two paralogous groups of sequences, DAB1 and DAB3, were recognised according to the similarity of their nucleotide and amino-acid sequences and from phylogenetic analyses using either partial exon 2 or partial exon 3 sequences. A high allelic variability among species was found for exon 2, indicating extensive MHC polymorphism. Time divergence estimation supports the separation of DAB1 and DAB3 groups predating the separation into fish subfamilies, and a cyprinid origin of the DAB genes. Phylogenetic trees using exon 2 support the hypothesis of trans-species polymorphism, which appears to be limited to the subfamily level, i.e. the presence of sequences from different species in the same allelic group was more often recognised within subfamilies Cyprininae and Leuciscinae than between them. Phylogenetic trees using exon 3 reflect the phylogenetic patterns previously found for Cyprinidae systematics. Specific nucleotides and amino-acids in exon 3 that separate both subfamilies, as well as the species within the Cyprininae subfamily were observed. A lack of segregation in leuciscin species was recognised and the alleles of different leuciscin species tend to share similar motifs in exon 3. This could be explained by the ancient and complicated dispersion history of Cyprininae and the radiation of Leuciscinae. The effects of selective pressures were investigated: (1) within species, (2) among lineages, and (3) among sites. From intraspecific analyses, exon 2 sequences were identified as the targets of diversifying selection, whilst the evolution of exon 3 seems to be under the influence of purifying selection. The analyses among lineages indicate positive selection in many branches when using exon 2, therefore confirming trans-species polymorphism, whilst the DAB lineages of exon 3 are potentially submitted to purifying selection to some extent. Moreover, our results suggest the secondary acquisition of function of DAB1 group after duplication. The analyses among sites reveal that exon 2 exhibits sites under positive selection mostly corresponding to the putative PBR sites involved in the alpha-helix structure of the protein.     

Cyprinid phylogeny based on Bayesian and maximum likelihood analyses of partitioned data: implications for Cyprinidae systematics

Cyprinidae is the biggest family of freshwater fish, but the phylogenetic relationships among its higher-level taxa are not yet fully resolved. In this study, we used the nuclear recombination activating gene 2 and the mitochondrial 16S ribosomal RNA and cytochrome b genes to reconstruct cyprinid phylogeny. Our aims were to (i) demonstrate the effects of partitioned phylogenetic analyses on phylogeny reconstruction of cyprinid fishes; (ii) provide new insights into the phylogeny of cyprinids. Our study indicated that unpartitioned strategy was optimal for our analyses; partitioned analyses did not provide better-resolved or -supported estimates of cyprinid phylogeny. Bayesian analyses support the following relationships among the major monophyletic groups within Cyprinidae: (Cyprininae, Labeoninae), ((Acheilognathinae, ((Leuciscinae, Tincinae), Gobioninae)), Xenocyprininae). The placement of Danioninae was poorly resolved. Estimates of divergence dates within the family showed that radiation of the major cyprinid groups occurred during the Late Oligocene through the Late Miocene. Our phylogenetic analyses improved our understanding of the evolutionary history of this important fish family.     

Molecular phylogeny of congeneric monogenean parasites (Dactylogyrus): a case of intrahost speciation

Dactylogyrus species (Dactylogyridae: Monogenea) are a group of monogenean gill parasites that are highly specific to freshwater fish of the family Cyprinidae. Dactylogyrus species were sampled from 19 cyprinids and one percid collected in Europe. Using partial 18S rDNA and ITS1 sequences, a phylogeny of 51 Dactylogyrus species was reconstructed to investigate the patterns of parasite speciation and diversification. Three main Dactylogyrus lineages were recognized from all phylogenetic trees, that is, analysis of 18S rDNA alone and combined 18SrDNA and ITS1. The first lineage associates the Dactylogyrus species of Cyprinus carpio and Carassius auratus of the Cyprininae; the second associates Dactylogyrus species of the Gobioninae, Pseudorasbora parva of the Rasborinae, and Ctenopharyngodon idella of the Cyprininae; and the third associates Dactylogyrus species of the Leuciscinae and Alburninae and Barbus barbus of the Cyprininae. Our results suggest that the genus Dactylogyrus is of quite recent origin and that these three lineages separated from each other in a very short period of time. Host subfamily mapping onto the parasite tree inferred from analysis of the combined dataset showed that the Cyprininae could be plesiomorphic hosts for Dactylogyrus. Dactylogyrus parasites would have secondarily colonized the Percidae and representatives of the Leuciscinae, Alburninae, Gobioninae, and Rasborinae. Comparison of host and parasite phylogenetic relationships indicated that a very high number of parasite duplications occurred within two of the three Dactylogyrus lineages. Dactylogyrus diversification can be mainly explained by sympatric intrahost speciation events that seem to be correlated to strict host specificity. Moreover, the present study shows that the congeneric parasites speciating within one host tend to occupy niches within hosts differing at least in one niche parameter.     

Molecular phylogenetic relationships of Eastern Asian Cyprinidae (Pisces: Cypriniformes) inferred from cytochrome b sequences

Cyprinidae, the largest fish family, comprises ap-proximately 210 recognized genera and 2010 species that are distributed widely in Eurasia, East Indian Is-land, Africa, and North America[1]. Species richness of this family is the greatest in East Asia, for example, China has 122 genera and more than 600 species. It is difficult to build a comprehensive phylogeny of Cy-prinidae due to the large number of genera and species. The classification of this family has been subject to revisions an…     

Molecular evidence for the monophyly of East Asian groups of Cyprinidae (Teleostei: Cypriniformes) derived from the nuclear recombination activating gene 2 sequences

The family Cyprinidae is one of the largest families of fishes in the world and a well-known component of the East Asian freshwater fish fauna. However, the phylogenetic relationships among cyprinids are still poorly understood despite much effort paid on the cyprinid molecular phylogenetics. Original nucleotide sequence data of the nuclear recombination activating gene 2 were collected from 109 cyprinid species and four non-cyprinid cypriniform outgroup taxa and used to infer the cyprinid phylogenetic relationships and to estimate node divergence times. Phylogenetic reconstructions using maximum parsimony, maximum likelihood, and Bayesian analysis retrieved the same clades, only branching order within these clades varied slightly between trees. Although the morphological diversity is remarkable, the endemic cyprinid taxa in East Asia emerged as a monophyletic clade referred to as Xenocypridini. The monophyly for the subfamilies including Cyprininae and Leuciscinae, as well as the tribes including Labeonini, Gobionini, Acheilognathini, and Leuciscini, was also well resolved with high nodal support. Analysis of the RAG2 gene supported the following cyprinid molecular phylogeny: the Danioninae is the most basal subfamily within the family Cyprinidae and the Cyprininae is the sister group of the Leuciscinae. The divergence times were estimated for the nodes corresponding to the principal clades within the Cyprinidae. The family Cyprinidae appears to have originated in the mid-Eocene in Asia, with the cladogenic event of the key basal group Danioninae occurring in the early Oligocene (about 31-30 MYA), and the origins of the two subfamilies, Cyprininae and Leuciscinae, occurring in the mid-Oligocene (around 26 MYA).     

Genus-level supertree of Cyprinidae (Actinopterygii: Cypriniformes), partitioned qualitative clade support and test of macro-evolutionary scenarios

We used the supertree approach of matrix representation with parsimony to reconstruct to date the most exhaustive (genus‐level) phylogeny of Cyprinidae. The supertree of Cyprinidae, representing 397 taxa (237 nominal genera) and 990 pseudocharacters, was well resolved (96%) through extended consensus majority rule, although 36 nodes (9.4%) were unsupported. The proportion of shared taxa among source trees was very low after calculation of the taxonomic coverage index (TCI = 0.059), which is proposed here as a more accurate alternative to the usual ratios calculated from the number of pseudo‐characters or source trees per taxon. We define a new index for the calculation of partitioned qualitative clade support, the partitioned rQS (_prQS), which offers a straightforward visualization of the relative supports of source tree partitions at supertree nodes.The use of _prQS showed that the molecular source tree partition contributed to most node supports within the supertree of Cyprinidae (73%, contra 21% for the morphological partition) and evidenced a fair proportion of conflict at nodes between the two partitions (21%), notably reflecting (i) the greater number and resolution of molecular source trees, and (ii) potential morphological convergences. Most of the higher‐level relationships within Cyprinidae were supported by both morphological and molecular source tree partitions. Our supertree showed a well‐supported dichotomy between a clade consisting of a ‘barbine’ + ‘rasborine’ lineage, sister group to (Barbinae [paraphyletic], (Cyprininae, Labeoninae)), and a clade consisting of other rasborines (large polytomy) and the two monophyletic groups ((Tincinae, Tanichthys), (Ecocarpia, (Acheilognathinae, (Gobioninae, Leuciscinae)))) and (Squaliobarbinae, (Xenocyprinae, Cultrinae)). Through the non‐monophyly of almost all the traditional subfamilies of Cyprinidae and 34 genera, our supertree exemplified the taxonomic chaos that reigns in the classification of the family. It also highlighted that further efforts should aim at increasing taxonomic sampling and generating alternative phylogenetic signals, notably for the still poorly apprehended Tincinae, Squaliobarbinae, Acheilognathinae, Gobioninae, and Rasborinae, the latter representing a key taxon for the understanding of early cyprinid evolution. Our supertree also proved useful for testing macro‐evolutionary scenarios at a wide taxonomic scale. Ancestral reconstructions using linear parsimony confirmed that the Oriental tropical region was the centre of origin of Cyprinidae, and identified three Oriental‐to‐Palaearctic, two Palaearctic‐to‐Nearctic, and one Oriental‐to‐Afrotropical major migration events. On the other hand, we almost completely rejected the hypothesis of presence of barbels as a plesiomorphic condition within Cyprinidae (although ambiguous for maxillary barbels of the Barbinae‐Cyprininae type). The supertree of Cyprinidae serves as a basis to discuss the applications and bias of the newly proposed _prQS, to provide future guidelines for a better achievement of cyprinid phylogeny, and to elaborate further on inter‐continental migrations and the adaptive value of barbels.     

中国鲤形目鱼类的中轴骨骼数及其生态适应性

为探讨中国鲤形目鱼类中轴骨骼数及其与系统发育和生态习性的相关性,采用X光透视照相法对157种鲤科(Cyprinidae)、鳅科(Cobitidae)、平鳍鳅科(Balitoridae)鱼类的脊椎骨数、肋骨数、尾椎数进行了比较分析。结果显示,中国鲤形目鱼类的脊椎骨数在30-52枚之间,均值39.45?4.44;肋骨数在8-28对之间,均值15.27?3.08;尾椎数在14-34枚之间,均值21.08?2.89。依据脊椎骨数、肋骨数、尾椎数对鲤科各亚科进行聚类,显示鲤科12个亚科分为2大类：雅罗鱼类,包括雅罗鱼亚科、鲌亚科、鲴亚科、裂腹鱼亚科等4亚科;鲃类,包括鲢亚科、鮈亚科、鱼丹亚科、鲃亚科、野鲮亚科、鳅鮀亚科、鲤亚科、鱊亚科等8亚科。单因素方差分析显示,鲤科肉食性鱼类的肋骨数与脊椎骨数的比值显著少于植食性鱼类(P＜0.05),而脊椎骨数、尾椎数则显著多于植食性鱼类(P＜0.05)。中上层鱼类的脊椎骨数、尾椎数显著多于下层鱼类(P＜0.05)。极小型鱼类的脊椎骨数、肋骨数,以及肋骨数与脊椎骨数之比显著少于大型鱼类(P＜0.05)。表明鲤科鱼类的中轴骨骼数与其系统发育和生态习性及体型具有明显的相关性。     

Phylogenetic relationships of Cyprinidae (Teleostei: Cypriniformes) inferred from the partial <Emphasis Type="Italic">S6K1</Emphasis> gene sequences and implication of indel sites in intron 1

The family Cyprinidae is widely distributed in East Asia, and has the important phylogenetic significance in the fish evolution. In this study, the 5′ end partial sequences (containing exon 1, exon 2 and indel 1) of S6K1 gene were obtained from 30 representative species in Cyprinidae and outgroup using PCR amplification and sequencing. The phylogenetic relationships of Cyprinidae were reconstructed with neighbor joining (NJ), maximum parsimony (MP), maximum likelihood (ML), and Bayesian methods. Myxocyprinus asiaticus (Catostomidae) was assigned to the outgroup taxon. Similar phylogenetic relationships within the family Cyprinidae were achieved with the four analyses. Leuciscini and Barbini were monophyletic lineages respectively with the high nodal supports. Leuciscini comprises Hypophthalmichthyinae, Xenocyprinae, Cultrinae, Gobioninae, Acheilognathinae and East Asian species of Leuciscinae and Danioninae. Monophyly of East Asian clade was supported with high nodal support. Barbini comprises Schizothoracinae, Barbinae, Cyprininae and Labeoninae. The monophyletic lineage consisting of Danio rerio, D. myersi, and Rasbora trilineata was basal in the tree. In addition, the large fragment indels in intron 1 were analyzed to improve the understanding of Cyprinidae relationships. The results showed that the large fragment indels were correlated with the relations among species. Some conserved regions in intron 1 were thought to be involved in the functional regulation. However, no correlation was found between sequence variations and species characteristic size.     

Complete mitochondrial genome of the grass carp (Ctenopharyngodon idella, Teleostei): insight into its phylogenic position within Cyprinidae

Genome comparison has shed light on many fields of both basic and applied research, including the study of species phylogeny. Grass carp (Ctenopharyngodon idella) belongs to Cyprinidae, the largest freshwater fish family; but which subfamily it belongs to remains a controversial issue. In this study, the complete mitochondrial genome (mitogenome) sequence of grass carp was determined and phylogenetic analyses of all mitochondrial protein-coding genes and a nuclear gene (RAG 2) were conducted to explore the evolutionary relationship of grass carp with other cyprinid species. The mitogenome of grass carp is 16,609 bp in length. As with most other vertebrates, it contains the same gene order and an identical number of genes or regions, including 13 protein-coding genes, two rRNA genes, 22 tRNA genes and one putative control region. Phylogenetic analyses using two different datasets (mitochondrial and nuclear) and three different computational algorithms (Bayesian, MP and ML) all revealed two distinct groups with high statistical support, indicating that Cyprininae and Leuciscinae are two separate, valid subfamilies. Importantly, our phylogenetic result provides strong molecular evidence in support of the placement of Ctenopharyngodon in Leuciscinae rather than in Cyprininae.     

Phylogenetic relationships of Cyprinidae (Teleostei: Cypriniformes) inferred from the partial S6K1 gene sequences and implication of indel sites in intron 1

The family Cyprinidae is widely distributed in East Asia, and has the important phylogenetic signifi- cance in the fish evolution. In this study, the 5′ end partial sequences (containing exon 1, exon 2 and indel 1) of S6K1 gene were obtained from 30 representative species in Cyprinidae and outgroup using PCR amplification and sequencing. The phylogenetic relationships of Cyprinidae were reconstructed with neighbor joining (NJ), maximum parsimony (MP), maximum likelihood (ML), and Bayesian meth- ods. Myxocyprinus asiaticus (Catostomidae) was assigned to the outgroup taxon. Similar phylogenetic relationships within the family Cyprinidae were achieved with the four analyses. Leuciscini and Barbini were monophyletic lineages respectively with the high nodal supports. Leuciscini comprises Hy- pophthalmichthyinae, Xenocyprinae, Cultrinae, Gobioninae, Acheilognathinae and East Asian species of Leuciscinae and Danioninae. Monophyly of East Asian clade was supported with high nodal support. Barbini comprises Schizothoracinae, Barbinae, Cyprininae and Labeoninae. The monophyletic lineage consisting of Danio rerio, D. myersi, and Rasbora trilineata was basal in the tree. In addition, the large fragment indels in intron 1 were analyzed to improve the understanding of Cyprinidae relationships. The results showed that the large fragment indels were correlated with the relations among species. Some conserved regions in intron 1 were thought to be involved in the functional regulation. However, no correlation was found between sequence variations and species characteristic size.     

Phylogeny and biogeography of the family Cyprinidae in the Middle East inferred from cytochrome b DNA- evolutionary significance of this region.

The phylogenetic relationships of cyprinid species from the Middle East and neighboring biogeographical areas were investigated using cytochrome b sequence variation in order to test hypotheses that consider the Middle Eastern area as an important interchange area or a center of speciation for the freshwater fauna. A total of 62 cyprinid species were analyzed over the complete cytochrome b fragment (1140 bp); 28 belong to the Leuciscinae subfamily and 34 to the Cyprininae. All the Leuciscinae lineage fish recorded in the Middle East are also found in Europe, which was interpreted as an important Palearctic influence in the Middle Eastern ichthyofauna consistent with the Lago Mare dispersion. However, it has also been suggested that several Danube species have their origins in the Middle East. In contrast, the Cyprininae subfamily showed three highly divergent lineages, one shared with the Euro-Mediterranean area (Barbus/Luciobarbus genus) relict of the Lago Mare dispersion, one shared with Africa (Carasobarbus/Varicorhinus subgenus), and the third shared with Asia (Garra genus). Furthermore, clades observed in the phylogenetic reconstructions are not consistent with morphometric or karyological data and disagree with previous taxonomic assumptions. Lastly, the dispersion history in the Middle East of this subfamily appears much more complicated and ancient than that of the Leuciscinae. However, taking into account Cyprininae and Leuciscinae distribution, the Middle East appears more like an important interchange area for the freshwater ichtyofauna than a center of speciation.     

中国鲤科鱼类染色体组型的研究Ⅹ.鲃亚科五种鱼和(鱼句)亚科四种鱼的染色体组型

本文报道了鲤科鲃亚科5种鱼和(鱼句)亚科4种鱼的染色体组型考察结果,并对这两个亚科鱼类的染色体数日和臂数进行了统计分析,讨论了其染色体进化及系统关系等问题。     

鲤科四种鱼肠道菌群的相似性及其与系统进化的关系

在同一背景条件下,对草鱼、白链、团头鲂和鲤等4种鱼的肠道菌群中好氧性菌或兼性厌氧菌进行分析鉴定,得到4种鱼之间的肠道菌群相似值。用UPGMA和NJ法构建鲤科的雅罗鱼亚科,链亚科,Bian亚科和鲤亚科等4种亚科的系统演化树。不同亚科的鱼间菌群分布有较大差异。但雅罗鱼亚科和Bian亚科和菌群分布方面有极显的正相关性,哈夫尼亚菌属、致病杆菌属、气单胞菌属、柠檬酸菌属、假单胞菌属等在4种鱼肠道中均有分布,链球菌属,拉恩氏菌属、牙包杆菌属、葡萄球菌属等属于共生菌,雅罗鱼亚科和Bian亚科相邻邻接为一个共同接点,该接点与鲤亚科连接为一个接点,鲤亚科可能是最原始的类型。     

Comparative phylogeography of endemic cyprinids in the south-west Iberian Peninsula: evidence for a new ichthyogeographic area

The comparative phylogeography and evolutionary history of three native cyprinid genera, Squalius (subfamily Leuciscinae), Chondrostoma (subfamily Leuciscinae) and Barbus (subgenus Luciobarbus ; subfamily Cyprininae), were examined focusing mainly in the South-Western region of the Iberian Peninsula, where recently described endemic species are present with considerably restricted distribution areas. In order to accomplish that the variation at the complete cytochrome b gene (1140 bp) was analysed for specimens from the South-Western region, and also for representatives of the three genera from all over the Iberian Peninsula. Data indicate different evolutionary histories, with distinct time periods of colonization between the two cyprinid subfamilies in the Iberian Peninsula. Four new Iberian ichthyogeographic areas are accordingly proposed based on congruent phylogeographic and geological evidences: the South-Western, the South-Eastern, the Atlantic and the Mediterranean. Evidence was provided for the older isolation of the South-Western area in the Miocene during the Endorheic Drainages phase, designating a clearly defined and distinct ichthyogeographic area. A new molecular clock calibration is proposed for the subgenus Luciobarbus .     

赣东北地区鱼类区系特征及我国东部地区动物地理区划

本文依据赣东北鱼类区系的特征,结合古地史资料,从历史时空的角度分析其区系的形成和演化;进而对我国东部地区淡水鱼类动物地理区划进行了讨论并指出：赣东北以及整个长江中下游地区应隶属于东洋区;南岭──武夷山──天台山──仙霞岭可构成东洋区南东亚亚区内次一级地理区划的分界线,即华东小区和华南小区的分界线;洞庭湖水系、鄱阳湖水系和钱塘江水系应享有相同的区划级别,同处于东洋区南东亚亚区华东小区内。     

Phylogenetic relationships of Iberian cyprinids: systematic and biogeographical implications.

The phylogenetic relationships among all Iberian endemic cyprinids were inferred using the complete nucleotide sequence of the cytochrome b gene. The inferred molecular phylogeny included representatives from Central European, Asian and North African species, and is highly congruent with previous phylogenies based on osteological characters. Iberian cyprinids were grouped into only five, very speciose lineages (with the exception of the monotypic Anaecypris): Barbus, Luciobarbus, Chondrostoma, Leuciscus and Anaecypris. The existence of such a relatively small number of Iberian cyprinid lineages can be explained by the historical isolation of the Iberian Peninsula. North African and Asian barbels are the sister group of Iberian Luciobarbus, supporting a south-eastern route of colonization of the Iberian Peninsula for this subgenus. With leuciscins, Anaecypris hispanica was considered a relict species as it could not be related to any other Iberian cyprinid. The phylogenetic relationships among the main lineages of Iberian cyprinids based on cytochrome b sequence data supported the traditional division of the Cyprinidae into two subfamilies: Cyprininae and Leuciscinae.     

Remarkable phylogenetic resolution of the most complex clade of Cyprinidae (Teleostei: Cypriniformes): A proof of concept of homology assessment and partitioning sequence data integrated with mixed model Bayesian analyses

Despite many efforts to resolve evolutionary relationships among major clades of Cyprinidae, some nodes have been especially problematic and remain unresolved. In this study, we employ four nuclear gene fragments (3.3 kb) to infer interrelationships of the Cyprinidae.A reconstruction of the phylogenetic relationships within the family using maximum parsimony, maximum likelihood, and Bayesian analyses is presented. Among the taxa within the monophyletic Cyprinidae, Rasborinae is the basal-most lineage; Cyprinine is sister to Leuciscine. The monophyly for the subfamilies Gobioninae, Leuciscinae and Acheilognathinae were resolved with high nodal support. Although our results do not completely resolve relationships within Cyprinidae, this study presents novel and significant findings having major implications for a highly diverse and enigmatic clade of East-Asian cyprinids. Within this monophyletic group five closely-related subgroups are identified. Tinca tinca, one of the most phylogenetically enigmatic genera in the family, is strongly supported as having evolutionary affinities with this East-Asian clade; an established yet remarkable association because of the natural variation in phenotypes and generalized ecological niches occupied by these taxa.Our results clearly argue that the choice of partitioning strategies has significant impacts on the phylogenetic reconstructions, especially when multiple genes are being considered. The most highly partitioned model (partitioned by codon positions within genes) extracts the strongest phylogenetic signals and performs better than any other partitioning schemes supported by the strongest 2Δln Bayes factor. Future studies should include higher levels of taxon sampling and partitioned, model-based analyses.     

Male primer endocrine responses to preovulatory female cyprinids under natural conditions in Sweden

This study investigated two related aspects of male-female reproductive interactions in the family Cyprinidae: (1) whether ovulating female rudd Scardinius erythrophthalmus (subfamily Leuciscinae) induce endocrine and gonadal priming responses in conspecific males, a phenomenon which has been described only in species from the subfamily Cyprininae such as goldfish, Carassius auratus, crucian carp Carassius carassius and common carp, Cyprinus carpio and (2) whether the stimuli mediating these responses are species-specific. Field studies of three sympatric European cyprinids, two leuciscins (S. erythrophthalmus and white bream Blicca bjoerkna) and one cyprinin (C. carassius), were conducted on fishes captured in Sweden in the spawning season and held in net pens under natural conditions. As previously reported in C. carassius, male S. erythrophthalmus increased milt (sperm and seminal fluid) volume and plasma concentrations of the sperm maturation hormone 4-pregnen-17,20β-diol-3-one (17,20β-P) when they were held with female S. erythrophthalmus induced to ovulate by injection of Ovaprim (GnRH analogue plus dopamine antagonist). Male S. erythrophthalmus had larger milt volumes than male C. carassius prior to and following exposure to ovulatory conspecifics, but exhibited a smaller proportional milt increase in response to stimulation, suggesting species differences in sperm allocation at spawning. The presence of female S. erythrophthalmus and B. bjoerkna did not affect milt volumes of C. carassius under two experimental conditions: (1) ovulating S. erythrophthalmus and B. bjoerkna did not increase the milt volumes of C. carassius and (2) S. erythrophthalmus and B. bjoerkna did not interfere with the milt volume increase induced in male C. carassius by ovulating conspecifics. These results suggest that, as in C. auratus, C. carassius and C. carpio (subfamily Cyprininae), female S. erythrophthalmus (subfamily Leuciscinae) release a preovulatory pheromone that exerts priming effects on male hormones and sperm allocation. The findings also indicate that C. carassius discriminate between the reproductive odours of conspecifics and heterospecifics.     

Cross-priming of microsatellite loci in subfamily cyprininae (family Cyprinidae): their utility in finding markers for population genetic analysis in three Indian major carps

This study is aimed to identify polymorphic microsatellite markers and establish their potential for population genetics studies in three carp (family cyprinidae; subfamily cyprininae) species, Labeo rohita, Catla catla and Cirrhinus mrigala through use of cyprinid primers. These species have high commercial value and knowledge of genetic variation is important for management of farmed and wild populations. We tested 108 microsatellite primers from 11 species belonging to three different cyprinid subfamilies, Cyprininae, Barbinae and Leuciscinae out of which 63 primers (58.33 %) successfully amplified orthologous loci in three focal species. Forty-two loci generated from 29 primers were polymorphic in these three carp species. Sequencing of amplified product confirmed the presence of SSRs in these 42 loci and orthologous nature of the loci. To validate potential of these 42 polymorphic loci in determining the genetic variation, we analyzed 486 samples of three focal species collected from Indus, Ganges and Brahmaputra river systems. Results indicated significant genetic variation, with mean number of alleles per locus ranging from 6.80 to 14.40 and observed heterozygosity ranging from 0.50 to 0.74 in the three focal species. Highly significant (P < 0.00001) allelic homogeneity values revealed that the identified loci can be efficiently used in population genetics analysis of these carp species. Further, thirty-two loci from 19 primers were useful for genotyping in more than one species. The data from the present study was compiled with cross-species amplification data from previous results on eight species of subfamily cyprininae to compare cross-transferability of microsatellite loci. It was revealed that out of 226 heterologous loci amplified, 152 loci that originated from 77 loci exhibited polymorphism and 45 primers were of multispecies utility, common for 2–7 species.