Phylogénie des touracos (Aves, Musophagidae). Analyse des caractères morphologiques

Phylogeny of turacos (Aves, Musophagidae). Analysis of morphological characters
A cladistic analysis of the 23 species of turacos (Musophagidae) using 34 morphological characters produces, after successive weighting, 4 shortest-length trees (consistency index = 0.76) that present two major clades: the first one with 'grey' turacos (genus Crinifer, Corythaixoides ), the other one with the great blue turaco (genus Corythaeola ) and the turacine bearers turacos (genus Tauraco , Musophaga , Ruwenzorornis , Gallirex ). This result also suggests that the species ' persa ' is not valid; T. schalowi , T. livingstonii , T. corythaix which were included in this species are more closely related to T. fisheri and T. schuettii than they are to T. persa . The polymorphism of these green turacos is also discussed. Ruwenzorornis johnstoni and Gallirex porphyreolophus do not belong to the Tauraco clade nor to the Musophaga clade, but they are closer to the first than to the second. The species Corythaixoides leucogaster is closer to the Crinifer species than to the other Corythaixoides species.     

Phylogenetic relationships of turacos (Musophagidae; Cuculiformes) based on comparative chromosome banding analysis

Cladistic analysis of chromosome banding patterns in nine species of turacos (Musophagidae; Cuculiformes) revealed the existence of two clades, one comprised of species of the genera Tauraco, Gallirex (= Tauraco ) and Musophaga , and another of species of Corythaixoides. The results are consistent with the allocation of the former to a subfamily Tauracinae and the allocation of the latter to the subfamily Criniferinae which also includes Crinifer. Comparative C-banding suggests that the putatively polytypic Tauraco corythaix is occupied by more than one species; more such studies in this group may resolve other questionable cases of conspecificity. Comparison of our results to studies of Cuculidae suggest that they do not share with musophagids two major derived fissions that set musophagids apart from other avian orders. Detailed comparison of ancestral karyotypes from several groups (Galliformes, Cuculidae, Musophagidae and Opisthocomidae) may help to resolve their still unresolved phylogenetic relationships.
Our results confirm previous studies showing karyotypic uniformity within avian orders. The uniformity suggests a negligible role for chromosome rearrangement in speciation in this group, since several indisputably distinct species do not differ karyotypically in any significant fashion. Intraspecific uniformity is punctuated by the presence in Livingstone's turaco Tauraco corythaix livingstonii of inversion heteromorphism, the class of rearrangement encountered most frequently in other avian species.     

Complete mitochondrial genome of Shinisaurus crocodilurus (Squamata: Shinisaurus) and its genetic relationship with related species

The 16,585 base pairs mitochondrial genome of Shinisaurus crocodilurus was determined by using PCR amplification and DNA sequencing. To determine the phylogenetic position of S. crocodilurus with related species within Squamata, the phylogenetic tree was reconstructed with the concatenated nucleotide sequences of the 12 heavy-strand-encoded protein genes. Phylogenetic analyses based on maximum parsimony and Bayesian inference methods consistently support that the S. crocodilurus was closely related to the Helodermatidae within a monophyletic Anguimorpha group. And the result here contradicted the monophyly of Varanoidea (Varanidae + Helodermatidae). In addition, the Gekkonidae was found to possess a basal phylogenetic position within squamata and the traditional hypothesis of monophyletic lineages of Iguania and Scleroglossa was not supported in this study.     

Monophyly and phylogeny of cuckoos (Aves, Cuculidae) inferred from osteological characters

A reanalysis of 32 characters from the literature previously deemed diagnostic of the Cuculidae revealed only five to be synapomorphic. I subsequently examined skeletons from 54 avian families and identified nine additional synapomorphies that supported cuckoo monophyly. My cladistic analysis of 33 cuculid genera using 135 skeletal characters differs markedly from currently accepted taxonomies. The most striking deviation is the placement of both New and Old World parasitic cuckoos in the Cuculinae, supporting the evolution of brood parasitism in a single event rather than three times as previously proposed. Unlike earlier classifications, the Cuculinae also includes the facultative parasites Coccyzus. This, suggests that the ancestral Coccyzus was an obligate parasite, and is consistent with the many behavioral adaptations to parasitism exhibited by this genus. Other changes include the placement of three subfamilies, comprising non-parasitic, terrestrial cuckoos of Old World (Centropodinae and Carpococcystinae) and New World (Neomorphinae) distribution, in basal positions on the tree. Nineteen characters support a sister relationship between the Hoatzin ( Opisthocamus hoatzin Müller) and turacos (Musophagidae), and not cuckoos. Three synapomorphies of the os carpi ulnare were found to unite the Cuculidae, turacos, and the Hoatzin, suggesting that these three diverse taxa may constitute a monophyletic group.     

Biomechanical features of the bill and and jaw apparatus of cuckoos,turacos and the hoatzin in relation to food acquisition and processing

A morphofunctional analysis of the feeding apparatus was conducted from an evolutionary perspective on the hoatzin (Opisthocomidae), some cuckoos (Cuculidae) and some turacos (Musophagidae). These goups share a common ancestral adaptation of the bill apparatus linked to starting food processing at base of the bill. The morphofunctional analyses give results different from what is known for the Galliformes and allow the construction of the hypothesis of two trophic adaptive pathways. One followed by the Cuculidae would have led to the consumption of a large range of arthropods, including toxic species; the other, followed by the Musophagidae and Opisthocomidae, would have led to the consumption of plant parts.     

Attempted Integration of Multiple Species of Turaco Into a Mixed‐Species Aviary

Mixed‐species exhibits offer a variety of benefits but can be challenging to maintain due to difficulty in managing interspecific interactions. This is particularly true when little has been documented on the behavior of the species being mixed. This was the case when we attempted to house three species of turaco (family: Musophagidae) together with other species in a walk‐through aviary. To learn more about the behavior of great blue turacos, violaceous turacos, and white‐bellied gray go‐away birds, we supplemented opportunistic keeper observations with systematic data collection on their behavior, location, distance from other birds, and visibility to visitors. Keepers reported high levels of aggression among turacos, usually initiated by a go‐away bird or a violaceous turaco. Most aggression occurred during feedings or when pairs were defending nest sites. Attempts to reduce aggression by temporarily removing birds to holding areas and reintroducing them days later were ineffective. Systematic data collection revealed increased social behavior, including aggression, during breeding season in the violaceous turacos, as well as greater location fidelity. These behavioral cues may be useful in predicting breeding behavior in the future. Ultimately, we were only able to house three species of turaco together for a short time, and prohibitively high levels of conflict occurred when pairs were breeding. We conclude that mixing these three turaco species is challenging and may not be the most appropriate housing situation for them, particularly during breeding season. However, changes in turaco species composition, sex composition, or exhibit design may result in more compatible mixed‐turaco species groups. Zoo Biol. 32:216–221, 2013. © 2012 Wiley Periodicals, Inc.     

Phylogenetic relationships within the Mysidae (Crustacea, Peracarida, Mysida) based on nuclear 18S ribosomal RNA sequences

Species of the order Mysida (Crustacea, Peracarida) are shrimp-like animals that occur in vast numbers in coastal regions of the world. The order Mysida comprises 1,053 species and 165 genera. The present study covers 25 species of the well-defined Mysidae, the most speciose family within the order Mysida. 18S rRNA sequence analysis confirms that the subfamily Siriellinae is monophyletic. On the other hand the subfamily Gastrosaccinae is paraphyletic and the subfamily Mysinae, represented in this study by the tribes Mysini and Leptomysini, consistently resolves into three independent clades, and hence is clearly not monophyletic. The tribe Mysini is not monophyletic either, and forms two clades of which one appears to be closely related to the Leptomysini. Our results are concordant with a number of morphological differences urging a taxonomic revision of the Mysidae.     

A phylogeny of Drosophilidae using the Amyrel gene: questioning the Drosophila melanogaster species group boundaries

In this study, the phylogenetic relationships of 164 species of the family Drosophilidae are discussed, using the Amyrel gene, a member of the α -amylase multigene family. This study focuses on numerous species groups in the subgenera Sophophora and Drosophila of the genus Drosophila but also includes other closely related genera. Nucleotide data were analysed by several methods: maximum parsimony, neighbour joining, maximum likelihood and Bayesian inference. Heterogeneity of base composition (mainly low GC contents in the species groups willistoni and saltans ) has been addressed. In all analyses, the genus Drosophila appeared paraphyletic. The subgenus Sophophora clearly appeared to be a monophyletic group, showing well-resolved clades, with the Neotropical groups arising in a basal position. Here, it is proposed to raise the species subgroups ananassae and montium to the rank of species group, and to restrict the melanogaster species group to the melanogaster subgroup plus the 'Oriental' subgroups, among which the suzukii subgroup is polyphyletic. Some related genera such as Zaprionus , Liodrosophila , Scaptomyza and Hirtodrosophila are clustered with, or inside the subgenus Drosophila , which is therefore paraphyletic and should be reviewed.     

On the phylogenetic relationships among tetraphyllidean,lecanicephalidean and diphyllidean tapeworm genera

This study had two main objectives: (1) to construct an extensive, explicit list of characters and character states that might serve as a starting point, and perhaps even a model, for the compilation of a more complete list of characters for all cestode taxa; and (2) to use this character list to generate a hypothesis of the phylogenetic relationships among species representing most of the tetraphyllidean, lecanicephalidean and diphyllidean genera. Specimens of one species in each of 48 genera of tetraphyllideans, eight genera of lecanicephalideans, the three genera of diphyllideans, two genera of proteocephalideans and two genera of trypanorhynchs, were examined as whole-mounts and sections, with light and scanning electron microscopy. A list of 120 morphological characters was compiled. Four phylogenetic analyses were conducted using PAUP* and/or NONA. The first was a comprehensive analysis with the 56 tetraphyllidean and lecanicephalidean species as ingroups and the remaining seven species as outgroups. The second was an analysis of the three diphyllidean species as ingroups and the two proteocephalidean and the two trypanorhynch species as outgroups. The third was an analysis of the eight lecanicephalidean species and the tetraphyllideans Echeneibothrium sp. and Pseudanthobothrium n. sp. as ingroups and an outgroup consisting of the seven species used as outgroups in the first analysis. In the fourth analysis, the ingroup consisted of the 14 hooked tetraphyllideans (onchobothriids), and the outgroup consisted of the seven species used as outgroups in the first analysis. The results of these analyses support the following phylogenetic hypotheses: The diphyllideans are monophyletic and Echinobothrium n. sp. and Macrobothridium sp. are more closely related to one another than either is to Ditrachybothridium macrocephalum. The tetraphyllideans, lecanicephalideans and proteocephalideans are more closely related to each other than they are to the diphyllideans or the trypanorhynchs. The ordinal status of the lecanicephalideans is dubious. The lecanicephalidean species are more closely related to some of the tetraphyllidean taxa than these tetraphyllidean taxa are to the remainder of the tetraphyllidean taxa. The proteocephalideans appear to belong within the tetraphyllidean clade. The tetraphyllidean species Echeneibothrium sp. and Pseudanthobothrium n. sp. are members of the lecanicephalidean clade. The position of Discobothrium n. sp. within the lecanicephalideans is dubious. Within the tetraphyllideans, the non-acetabulate species Litobothrium daileyi, Disculiceps galapagoensis and Cathetocephalus sp. are the most basal members of the group. The family Onchobothriidae is monophyletic, as it is currently defined. Within the onchobothriids, the uniloculate species are basal to the multiloculate species; the species with unipronged hooks are basal to the species with multipronged hooks. Although relationships among the phyllobothriids, as they are currently defined, remain poorly resolved, the family Phyllobothriidae is not monophyletic. These results suggest that some aspects of the classification of the lecanicephalidean and tetraphyllidean taxa require revision. However, such revision should be based on further analyses including a broader representation of the genera and species in these groups.     

Molecular phylogeny of the Caryophyllaceae (Caryophyllales) inferred from chloroplast matK and nuclear rDNA ITS sequences

Caryophyllaceae is a principally holarctic family including around 2200 species often classified into the three subfamilies Alsinoideae, Caryophylloideae, and Paronychioideae. Complex and possibly homoplasious morphological characters within the family make taxa difficult to delimit and diagnose. To explore part of the morphological evolution within the family, we investigated the phylogeny of the Caryophyllaceae by means of analyzing plastid and nuclear sequence data with parsimony and Bayesian methods. We describe a mode of tracing a stable phylogenetic signal in ITS sequences, and a significant common signal is shared with the plastid data. Parsimony and Bayesian analyses yield some differences in tree resolution. None of the subfamilies appear monophyletic, but the monophyly of the Caryophylloideae is not contradicted. Alsinoideae are paraphyletic, with Arenaria subg. Eremogone and Minuartia subg. Spergella more closely related to the Caryophylloideae. There is strong support for the inclusion of Spergula-Spergularia in an Alsinoideae-Caryophylloideae clade. Putative synapomorphies for these groupings are twice as many stamens as number of sepals and a caryophyllad-type of embryogeny. Paronychioideae form a basal grade, where tribe Corrigioleae are sister to the rest of the family. Free styles and capsules with simple teeth are possibly plesiomorphic for the family.     

Phylogenetic relationships of Danio within the order Cypriniformes: a framework for comparative and evolutionary studies of a model species

The evolutionary relationships of species of Danio and the monophyly and phylogenetic placement of the genus within the family Cyprinidae and subfamily Rasborinae provide fundamentally important phyloinformatics necessary for direct evaluations of an array of pertinent questions in modern comparative biology. Although the genus Danio is not one of the most diverse within the family, Danio rerio is one of the most important model species in biology. Many investigations have used this species or presumed close relatives to address specific questions that have lasting impact on the hypothesis and theory of development in vertebrates. Largely lacking from this approach has been a holistic picture of the exact phylogenetic or evolutionary relationships of this species and its close relatives. One thing that has been learned over the previous century is that many organismal attributes (e.g., developmental pathways, ecologies, behaviors, speciation) are historically constrained and their origins and functions are best explained via a phylogenetic approach. Herein, we provide a molecular evaluation of the phylogenetic placement of the model species Danio rerio within the genus Danio and among hypothesized closely related species and genera. Our analysis is derived from data using two nuclear genes (RAG1, rhodopsin) and five mitochondrial genes (ND4, ND4L, ND5, COI, cyt b) evaluated using parsimony, maximum likelihood, and Bayesian analyses. The family Cyprinidae is resolved as monophyletic but the subfamily Rasborinae (priority over Danioinae) is an unnatural assemblage. Danio is identified as a monophyletic group sister to a clade inclusive of the genera Chela, Microrasbora, Devario, and Inlecypris, not Devario nor Esomus as hypothesized in previous studies. Danio rerio is sister to D. kyathit among the species of Danio evaluated in this analysis. Microrasbora and Rasbora are non-monophyletic assemblages; however, Boraras is monophyletic.     

Phylogenetic relationships, morphological incongruence, and geographic speciation in the fontinalaceae (Bryophyta)

Nuclear ribosomal DNA (internal transcribed spacer region) and chloroplast DNA (trnL-trnF region) were sequenced from 40 samples representing all three genera (Brachelyma, Dichelyma, and Fontinalis) and 18 species of the aquatic moss family, Fontinalaceae. Phylogenetic reconstructions recovered from separate and combined analyses were used to test the hypotheses that Fontinalis and Dichelyma are monophyletic (Brachelyma is monotypic), that groups of species within Fontinalis based on leaf morphology (keeled, concave, plane) form monophyletic groups, and that species delineation based on morphological characters within Fontinalis are congruent with nr- and cpDNA gene trees. Using Brachelyma subulata to root the tree, both Dichelyma and Fontinalis are monophyletic and patristically divergent (each united by >15 synapomorphic mutations). Groups of species within Fontinalis defined by leaf morphology are polyphyletic and it is clear that leaf morphology is labile in the genus. As defined morphologically, species of Fontinalis are nonmonophyletic for both nr- and cpDNA sequences and populations of some morphological taxa are separated in widely divergent clades. Molecular evidence suggests that at least some morphospecies are artificial, defined by convergent leaf forms. The weight of the evidence indicates that F. antipyretica is positively paraphyletic, with European populations more closely related to (i.e., share a more recent common ancestor with) European endemic species than to North American populations that are morphologically conspecific. North American populations are more closely related to North American endemic species.     

Phylogeny and classification of the Grimmiaceae/Ptychomitriaceae complex (Bryophyta) inferred from cpDNA

Phylogenetic relationships within the Grimmiaceae/Ptychomitriaceae were studied using a plastid tRNA cluster, including four tRNAs (trnS, trnT, trnL, trnF), a fast evolving gene (rps4), four spacers separating the coding regions, as well as one group I intron. Secondary structure analyses of the spacers as well as the trnL intron P8 domain identified several homoplastic inversions. Tracing the structural evolution of P8 we were able to identify lineage specific modifications that are mainly explained by inversions often in combination with large indel events. Phylogenetic analyses using maximum parsimony, maximum likelihood, and Bayesian methods indicate that Jaffueliobryum and Indusiella are closely related to Ptychomitrium and form the Ptychomitriaceae s. str. As Campylostelium is neither resolved within Ptychomitriaceae s. str. nor Grimmiaceae s. str., we prefer to treat it in its own family, Campylosteliaceae De Not. The systematic position of Glyphomitrium, as also found by other authors, should be considered in a broader analysis of haplolepidous mosses as our analyses indicate that it is not part of Campylosteliaceae, Grimmiaceae, or Ptychomitriaceae. Within Grimmiaceae s. str., Racomitrium is recognized as a monophyletic group sister to a clade including Dryptodon, Grimmia, and Schistidium. Coscinodon species appear disperse in Grimmia s. str. next to species sharing the same gametophyte morphology, and thus the genus is synonymized with Grimmia. Finally, Schistidium is resolved monophyletic with high statistical support, and seems to represent a rapidly evolving group of species. Our results are not fully congruent with recently published treatments splitting Grimmiaceae in a fairly high number of genera, neither with a comprehensive Grimmia including Dryptodon and Grimmia s. str.     

Molecular phylogeny of Rhacophoridae (Anura): A framework of taxonomic reassignment of species within the genera Aquixalus, Chiromantis, Rhacophorus, and Philautus

Phylogenetic relationships among representative species of the family Rhacophoridae were investigated based on 2904bp of sequences from both mitochondrial (12S rRNA, 16S rRNA, the complete t-RNA for valine), and nuclear (tyrosinase, rhodopsin) genes. Maximum parsimony, maximum likelihood, and Bayesian analyses were employed to reconstruct the phylogenetic trees. This analysis, combined with previous phylogenetic studies, serves as a framework for future work in rhacophorid systematics. The monophyly of Rhacophorus is strongly confirmed except for the species R.hainanus, which is the sister taxon to A.odontotarsus. The non-monophyly of the newly designated genus Aquixalus by Delorme et al. [Delorme, M., Dubois, A., Grosjean, S., Ohler, A., 2005. Une nouvelle classification générique et subgénérique de la tribu des Philautini (Amphibia, Anura, Ranidae, Rhacophorinae). Bull. Mens. Soc. Linn. Lyon 74, 165-171] is further confirmed. Aquixalus (Aquixalus) forms a well-supported monophyletic group within Kurixalus, whereas, Aquixalus (Gracixalus) is more closely related to species of Rhacophorus, Polypedates, and Chiromantis. Philautus as currently understood, does not form a monophyletic group. Philautus (Kirtixalus) is the sister group to the clade comprising Kurixalus and Aquixalus (Aquixalus), and more remotely related to Philautus (Philautus). Chiromantisromeri does not cluster with species of Chiromantis, and forms a basal clade to all rhacophorids save Buergeria. We propose some taxonomic changes that reflect these findings, but further revision should await more detailed studies, which include combined morphological and molecular analyses, with greater species sampling.     

Variability and phylogenetic significance of detachable nodes in feathers of tinamous, galliforms and turacos

The occurrence of detachable nodal structures in the downy barbules of many birds was studied with light- and scanning electron microscopy. Anuli are the only type of nodal structure that may break loose and slide along the barbules to form dual or multiple nodes. Considerable variation exists in the occurrence of this feature. Multiple nodes are more frequently present in tail-coverts than in breast feathers. This is the first report of the presence of detachable anuli in feathers of Cracidae, Numididae and Musophagidae. The suggestion by earlier workers that these structures are characteristic for all galliforms is not confirmed, since megapodes never show detached nodes. The downy barbules of Afropavo resemble those of other phasianids in all respects, while those of Opisthocomus are strikingly different from both galliforms and cuckoos. Outgroup comparison indicates that multiple nodes may be synapomorphic for Tinamidae, Cracidae, Tetraonidae, Phasianidae, Numididae, Meleagridae and Musophagidae together, but, considering the incongruence of this hypothesis with recently proposed phylogenies, alternative explanations for the structural similarities between the downy barbules of tinamous, turacos and galliforms are discussed.     

A molecular phylogenetic analysis of the family Rhacophoridae with an emphasis on the Asian and African genera

Using characters from mitochondrial DNA to construct maximum parsimony and maximum likelihood trees, we performed a phylogenetic analysis on representative species of 14 genera: 12 that belong to the treefrog family Rhacophoridae and two, Amolops and Rana, that are not rhacophorids. Our results support a phylogenetic hypothesis that depicts a monophyletic family Rhacophoridae. In this family, the Malagasy genera Aglyptodactylus, Boophis, Mantella, and Mantidactylus form a well-supported sister clade to all other rhacophorid genera, and Mantella is the sister taxon to Mantidactylus. Within the Asian/African genera, the genus Buergeria forms a well-supported clade of four species. The genera, except for Chirixalus, are generally monophyletic. An exception to this is that Polypedates dennysii clusters with species of Rhacophorus, suggesting that the taxonomy of the rhacophorids should be revised to reflect this relationship. Chirixalus is not monophyletic. Unexpectedly, there is strong support for Chirixalus doriae from Southeast Asia forming a clade with species of the African genus Chiromantis, suggesting that Chiromantis dispersed to Africa from Asia. Also, there is strong support for the sister taxon relationship of Chirixalus eiffingeri and Chirixalus idiootocus apart from other congeners.     

Phylogenetics and evolution of the aphid genus Uroleucon based on mitochondrial and nuclear DNA sequences

The genus Uroleucon, and the related genus Macrosiphoniella, represent a large Tertiary radiation of aphids, with a total of about 300 species distributed throughout the world, primarily on host plant species in the family Asteraceae. A molecular phylogenetic study was conducted to identify major clades within Uroleucon and to address the cladistic validity of current subgeneric categories, the evolution of host plant associations, the age of origin, and intercontinental movements in this genus. The seventeen study species included members of the three major subgenera of Uroleucon, species from Europe and North America, one member of Macrosiphoniella, and two outgroups. Data consisted of DNA sequences for three mitochondrial regions and the nuclear gene EF1alpha, for a total of 4287 sites. Nodes supported strongly in both parsimony and maximum likelihood analyses suggest that: (1) Nearctic Uromelan are a monophyletic group branching near the base of the genus and not related to European Uromelan, (2) the New World subgenus Lambersius is possibly monophyletic but is not a tightly related group and is not closely related to other North American species, and (3) Nearctic members of subgenus Uroleucon are a closely related monophyletic group not allied with Nearctic Uromelan or Lambersius. Instead they represent a separate colonization by an Old World ancestor, as they are nested within a strongly supported clade containing European members of both subgenera Uroleucon and Uromelan. Neither of these subgenera is monophyletic. Molecular clock calculations, based on calibrations of mitochondrial divergences from other insects, suggest that Uroleucon + Macrosiphoniella is a relatively recent radiation, probably no more than 5–10 million years old. Although largely confined to Asteraceae, this clade did not radiate in parallel with its host plants. Rather, lateral movement between lineages of Asteraceae must have occurred repeatedly.     

Sequence alignment of 18S ribosomal RNA and the basal relationships of Adephagan beetles: evidence for monophyly of aquatic families and the placement of Trachypachidae

Current hypotheses regarding family relationships in the suborder Adephaga (Coleoptera) are conflicting. Here we report full-length 18S ribosomal RNA sequences of 39 adephagans and 13 outgroup taxa. Data analysis focused on the impact of sequence alignment on tree topology, using two principally different approaches. Tree alignments, which seek to minimize indels and substitutions on the tree in a single step, as implemented in an approximate procedure by the computer program POY, were contrasted with a more traditional procedure based on alignments followed by phylogenetic inference based on parsimony, likelihood, and distance analyses. Despite substantial differences between the procedures, phylogenetic conclusions regarding basal relationships within Adephaga and relationships between the four suborders of Coleoptera were broadly similar. The analysis weakly supports monophyly of Adephaga, with Polyphaga usually as its sister, and the two small suborders Myxophaga and Archostemata basal to them. In some analyses, however, Polyphaga was reconstructed as having arisen from within Hydradephaga. Adephaga generally split into two monophyletic groups, corresponding to the terrestrial Geadephaga and the aquatic Hydradephaga, as initially proposed by Crowson in 1955, consistent with a single colonization of the aquatic environment by adephagan ancestors and contradicting the recent proposition of three independent invasions. A monophyletic Hydradephaga is consistently, though not strongly, supported under most analyses, and a parametric bootstrapping test significantly rejects an hypothesis of nonmonophyly. The enigmatic Trachypachidae, which exhibit many similarities to aquatic forms but whose species are entirely terrestrial, were usually recovered as a basal lineage within Geadephaga. Strong evidence opposes the view that terrestrial trachypachids are related to the dytiscoid water beetles.     

Molecular Systematics of Selene (Perciformes: Carangidae) Based on Cytochrome b Sequences

The marine fishes of the genus Selene are morphologically unique, although little is known about how these species are related to other members of the family Carangidae (Perciformes). In addition, questions remain about the potential validity of two putative species and how species groups with unique body forms within Selene are related. We used DNA sequences of the mitochondrial cytochrome b gene to reconstruct the phylogeny of the seven species of Selene along with five additional species of carangids. Maximum-likelihood and maximum-parsimony analyses were used to examine the sequence data and both phylogenetic methods were compared. Maximum-likelihood produced a monophyletic Selene, whereas parsimony analyses did not. Both maximum-likelihood and maximum-parsimony produced similar support for species groups within Selene. Maximum-likelihood produced two monophyletic subgroups within the genus Selene, the "long-finned" and "short-finned" Selene. Maximum-parsimony produced the same monophyletic "long-finned" group but a paraphyletic "short-finned" group. Both analyses confirm that S. brownii and S. setapinnis are distinct species, expunging the question of conspecificity. The phylogenetic placement of the most basal taxon within Selene, S. orstedii, was problematic and differed among analyses. More data are needed to resolve with confidence its correct phylogenetic placement and, thus, the monophyly of the genus Selene.     

豉甲科及水生肉食亚目的分子系统发育学分析(昆虫纲：鞘翅目)

利用PAUP和MrBayes软件,对线粒体COⅠ基因序列3个密码子位置的数据模块分别进行了豉甲科(Gyrinidae)和水生肉食亚目(Hydradephaga)在亚科或科水平上的系统发育学分析,结果表明第二密码子数据模块获得了理想的分析结果。由PAUP生成的豉甲科最优树来自第二密码子数据模块的分析,而由MrBayes生成的最优树来自全部密码子数据模块的分析。此外,用对应的氨基酸序列生成的ME和MP树与第二密码子数据模块分析的结果也一致。亚科Orectochilinae和Gyrininae以高的支持率形成了单系。然而,来自亚科Enhydrinae的种Porrorhynchus landaisi landaisi呈现了异常的位置。SH-test检验也支持该异常位置,表明这个种可能代表了一个科。在来自第二密码子数据模块的水生肉食亚目最优ML树中,整个Hydradephaga树呈现单系,豉甲科位于树的基部,表明了该科在水生肉食亚目中是一个早期的分支。在树中还产生了一个单系的Dytiscoidea总科,由Dytiscidae、Hygrobiidae、Noteridae和Amphizoidae 4个科组成,单系的Haliplidae与之成为姐妹群。此外线粒体分子钟的结果表明豉甲科的5对相近种间的分化是一个短时期内发生的(0.01～1.81百万年前),这点可能与它们的特殊地理分布有关。