Phylogeny of Tubificidae (Annelida, Clitellata) based on mitochondrial and nuclear sequence data

The tubificid clitellates are a common component in the freshwater bottom fauna and are also the most abundant oligochaete group in marine habitats. There are over 800 described species classified in six subfamilies; Tubificinae, Limnodriloidinae, Rhyacodrilinae, Telmatodrilinae, Phallodrilinae, and Naidinae. In this study we examine the phylogenetic relationships in Tubificidae using a combination of mitochondrial 16S rDNA and nuclear 18S rDNA sequence data. Sequences were obtained from five outgroup and 56 ingroup taxa, including five of the six subfamilies of Tubificidae. The data were analysed by maximum parsimony and Bayesian inference. The resulting tree topologies are virtually without conflict. Several associations traditionally recognized within the family Tubificidae are supported, in the Bayesian analysis including a sister group relationship between Tubificinae and Limnodriloidinae. The results also indicate that Rhyacodrilinae is polyphyletic--some of its members (Heterodrilus spp.) fall into a clade with Phallodrilinae, all other groups with Naidinae. Naidinae is also polyphyletic with two rhyacodriline genera, Monopylephorus and Ainudrilus, nested within. Most of the tubificid genera included in the study are supported as monophyletic; however, Tubifex and Limnodriloides are refuted, and Tubificoides is unresolved from other tubificine taxa.     

18S rDNA phylogeny of the Tubificidae (Clitellata) and its constituent taxa: dismissal of the Naididae

The phylogeny of the Tubificidae, and of most of its subfamilies and some of its genera, is revisited, on the basis of sequences of 18S ribosomal DNA in a selection of species. Forty-six new 18S sequences of Naididae (6), Tubificidae (37), Phreodrilidae (1), Lumbriculidae (1), and Enchytraeidae (1) are reported and aligned together with corresponding sequences of 21 previously studied taxa. The 18S gene of Insulodrilus bifidus provides the first molecular evidence that phreodrilids are closely related to tubificids, corroborating previous conclusions based on morphology. The data further support the monophyletic status of Tubificidae, provided that the "Naididae" is regarded a part of this family; "naidids" may not even constitute a monophyletic group. It is thus suggested that the family name Naididae is formally suppressed as a junior synonym of the Tubificidae. The 18S gene also resolves a number of relationships within the tubificids. Among the subfamilies, Tubificinae is supported, Rhyacodrilinae and Phallodrilinae are revealed as nonmonophyletic, and Limnodriloidinae remains unresolved. Most tubificid genera tested for monophyly are corroborated by the data, only one (Tubifex) is refuted, and two (Tubificoides and Limnodriloides) are unresolved from other taxa. It is concluded that it will be valuable to expand the taxonomic sampling for 18S rDNA in clitellates, and in annelids in general, as this is likely to improve the resolution at many levels. However, it will be equally important to combine the annelid 18S data with other gene sequences and nonmolecular characters, to estimate the phylogeny of these common and diverse worms with greater precision.     

Phylogenetic analysis of Tubificidae (Annelida, Clitellata) based on 18S rDNA sequences

Tubificids are aquatic clitellate worms, but recent analyses of morphological characters suggested that this family, as currently recognized, is paraphyletic. Sequences of the 18S rDNA gene of 40 protostome worm species (including 13 representatives of the Tubificidae) and 2 mollusc species were cladistically analyzed to test the monophyly of the Tubificidae and that of some of its constituent subfamilies. Under all alignments tested, the same general phylogenetic pattern emerged. The data support the idea that the Naididae, another clitellate taxon, is associated with some "rhyacodriline" groups within the Tubificidae. The data also corroborate the idea that the Tubificinae and the Limnodriloidinae are monophyletic but indicate that the Rhyacodrilinae and the Phallodrilinae are not. Bathydrilus does not appear to be closely related to other "phallodriline" genera.     

Aspects of the phylogeny of the marine Tubificidae

A tentative phylogeny of the oligochaete family Tubificidae, with emphasis on the marine representatives, is presented. The scheme is based on the morphology and arrangements of prostate glands and the setal patterns. The rhyacodriline, more or less diffuse prostates are regarded as a primitive stage in prostate evolution, preceded only by the aprostate condition assumed for the ancestor of the family. An early split of the subfamily Rhyacodrilinae supposedly led to (1) a marine branch, from which evolved the highly diverse, exclusively marine subfamilies Phallodrilinae and Limnodriloidinae, and (2) a freshwater branch, which later divided into the Telmatodrilinae, Tubificinae and Aulodrilinae. The marine subfamilies invariably lack hair setae, whereas about half of the species within the other, freshwater subfamilies possess such setae in their dorsal bundles. Some marine genera, such as Monopylephorus (Rhyacodrilinae), Tubificoides and Clitellio (both Tubificinae) are regarded as recent off-shoots from the main freshwater stock.The families Naididae and Opistocystidae are considered likely to have evolved from rhyacodriline Tubificidae, whereas Phreodrilidae, the fourth family within the suborder Tubificina, is regarded as a sister group to the Tubificidae.     

A test of monophyly of the gutless Phallodrilinae (Oligochaeta, Tubificidae) and the use of a 573-bp region of the mitochondrial cytochrome oxidase I gene in analysis of annelid phylogeny

A 573-bp region of the mitochondrial gene cytochrome c oxidase subunit I (COI) of two species of Inanidrilus Erséus and four species of Olavius Erséus (Phallodrilinae, Tubificidae) is used in a parsimony analysis together with a selection of 35 other annelids (including members of Polychaeta, Pogonophora, Aphanoneura, and the clitellate taxa Tubificidae, Enchytraeidae, Naididae, Lumbriculidae, Haplotaxidae, Lumbricidae, Criodrilidae, Branchiobdellida and Hirudinea), and with two molluscs as outgroups. The data support the monophyly of the Olavius and Inanidrilus group, with a monophyletic Inanidrilus . However, parsimony jackknife analyses show that most of the other groups are unsupported by the data set, thus revealing a large amount of homoplasy in the selected gene region. Practically no information is given of within/between family relationships except for a few, closely related species. This suggests that the analysed COI region is not useful, when used alone, for inferring higher level relationships among the annelids.     

Cuticular ultrastructure in some marine oligochaetes (Tubificidae)

Abstract. The ultrastructure of the thin, non-cellular cuticle is described for 6 marine oligochaetes, representing 3 of the subfamilies (Phallodrilinae, Limnodriloidinae, and Rhyacodrilinae) of the Tubificidae. The main components of the cuticle in these 6 species, as in most other oligochaetes examined, are: (1) a fiber zone closest to the epidermis, consisting of collagen fibers embedded in a matrix, (2) an epicuticle, which is a continuation of the matrix outside the fiber zone, and (3) epicuticular projections, which are membrane-bound bodies covering the outer surface of the epicuticle. The projections are probably formed by the microvilli that penetrate the cuticle from the epidermal cells below, but this was confirmed only in the studied limnodriloidines. Three of the species examined, Duridrilus turdus, Olavius vacuus , and Heterodrilus paucifascis , lack microvilli. The morphology of the components in the cuticle differs between the studied species. The collagen fibers may form an "orthogonal grid" (i.e., layers of parallel fibers perpendicular to the layers immediately above and below), or they may form parallel layers, or be irregularly scattered. The number of dense layers in the epicuticle, as well as the shape and internal structure of the epicuticular projections, also vary. All these characters might be useful in future phylogenetic analyses to achieve better hypotheses of relationships within oligochaetes as well as to other groups.     

Marine Tubificidae (Oligochaeta) of Antarctica, with descriptions of three new species of Phallodrilinae

Five species of Tubificidae are recorded from Antarctic waters: Torodrilus lowryi Cook, 1970, Torodrilus sp. (subfamily Rhyacodrilinae), Marionidrilus antarcticus sp. n., M. weddellensis sp. n., and Thalassodrilus bicki sp. n. (subfamily Phallodrilinae); only T. lowryi was known from Antarctica before. The status of the two Southern Hemisphere genera Torodrilus Cook, 1970, and Marionidrilus Erséus, 1992, are discussed; although the taxonomic position of the two new species of Marionidrilus is somewhat uncertain. Thalassodrilus bicki , however, appears closely related to Northern Hemisphere taxa.     

The Baikalian genus Rhyacodriloides in Europe: phylogenetic assessment of Rhyacodriloidinae subfam. n. within the Naididae (Annelida)

Martin, P., Martínez‐Ansemil, E. & Sambugar, B. (2010). The Baikalian genus Rhyacodriloides in Europe: phylogenetic assessment of Rhyacodriloidinae subfam. n. within the Naididae (Annelida). —Zoologica Scripta, 39, 462–482. Two new species of the oligochaete genus Rhyacodriloides Chekanovskaya, Rhyacodriloides aeternorum sp. n. and Rhyacodriloides latinus sp. n., are described from subterranean water bodies of Italy and Slovenia. A comparison with the known species of this genus, Rhyacodriloides abyssalis Chekanovskaya, 1975 and Rhyacodriloides gladiiseta Martin & Brinkhurst, 1998, both from Lake Baikal, shows that the enigmatic ‘cellular masses’ of the latter two species must be interpreted as different, not homologous structures. As a result, R. gladiiseta is to be ascribed to the Phallodrilinae, a primarily marine naidid subfamily, mentioned for the first time in Lake Baikal, and placed in its own genus, Phallobaikalus gen. n. The two new species are morphologically very similar, but their penial setae differ slightly. The phylogenetic relationships of R. latinus sp. n. and R. abyssalis within the Naididae (formerly the Tubificidae) were investigated using a combination of three genes, one nuclear (18S rDNA) and two mitochondrial (12S rDNA and 16S rDNA). A fragment of the mitochondrial COI gene, used as a barcode, also genetically characterized all Rhyacodriloides species. Sequences of 34 Naididae were obtained from EMBL, representative of five naidid subfamilies, and including five oligochaete outgroups. The data were analysed by parsimony, maximum likelihood and Bayesian inference. Taken in combination, the three genes investigated confirm that the two Rhyacodriloides species analysed are closer to each other than to any other naidid species. However, they are separated by 16S and COI distances that amount to 18.5% and 27.2%, respectively, suggesting an ancient separation between species, in good accordance with their present biogeographic distribution. Rhyacodriloides cannot be considered as a rhyacodriline, as assumed so far, as they never appeared related to this subfamily in any analysis considered. In contrast, they appear at the base of a naidid group, including the Tubificinae, the Phallodrilinae, the Limnodrilinae, as well as Branchiura sowerbyi, a species whose phylogenetic association with the rhyacodrilines has been questioned for a long time. Despite a lack of phylogenetic support, this position is congruent with a morphological reassessment of the Rhyacodrilinae, and strongly supports the erection of a new naidid subfamily to accommodate Rhyacodriloides.     

New insights into the phylogenetic relationships among the oceanic dolphins (Cetacea: Delphinidae)

The phylogenetic relationships of oceanic dolphins (family Delphinidae) remain unclear. Several works using mitochondrial and/or nuclear DNA on different genera and species have been published, though no consensus exists regarding even the subfamilies that conform the family. Here, a new phylogeny for the family Delphinidae, including 36 different complete mitochondrial genomes (plus two outgroups), was constructed under Bayesian and maximum likelihood approaches. Results indicate identical tree topology in both cases, with almost all nodes fully supported independently of the reconstruction approach. This topology is different from those previously published and proposes new phylogenetic relationships among subfamilies, genera and species of the family. These findings are critically important for the study of oceanic dolphin taxonomy, ecology, evolution and conservation, and highlight the importance of revisiting and resolving uncertain phylogenies.     

Phylogeny of Myrmeleontiformia based on larval morphology (Neuropterida: Neuroptera)

The suborder Myrmeleontiformia is a derived lineage of lacewings (Insecta: Neuroptera) including the families Psychopsidae, Nemopteridae, Nymphidae, Ascalaphidae and Myrmeleontidae. In particular, Myrmeleontidae (antlions) are the most diverse neuropteran family, representing a conspicuous component of the insect fauna of xeric environments. We present the first detailed quantitative phylogenetic analysis of Myrmeleontiformia, based on 107 larval morphological and behavioural characters for 36 genera whose larvae are known (including at least one representative of all the subfamilies of the suborder). Four related families were used as outgroups to polarize character states. Phylogenetic analyses were conducted using both parsimony and Bayesian methods. The reconstructions resulting from our analyses corroborate the monophyly of Myrmeleontiformia. Within this clade, Psychopsidae are recovered as the sister family to all the remaining taxa. Nemopteridae (including both subfamilies Nemopterinae and Crocinae) are recovered as monophyletic and sister to the clade comprising Nymphidae + (Myrmeleontidae + Ascalaphidae). Nymphidae consist of two well‐supported clades corresponding to the subfamilies Nymphinae and Myiodactylinae. Our results suggest that Ascalaphidae may not be monophyletic, as they collapse into an unresolved polytomy under the Bayesian analysis. In addition, the recovered phylogenetic relationships diverge from the traditional classification scheme for ascalaphids. Myrmeleontidae are reconstructed as monophyletic, with the subfamilies Stilbopteryginae, Palparinae and Myrmeleontinae. We retrieved a strongly supported clade comprising taxa with a fossorial habit of the preimaginal instars, which represents a major antlion radiation, also including the monophyletic pit‐trap building species.     

蹄盖蕨科的亚科划分的修订

蹄盖蕨科Athyriaceae是蕨类植物中复杂的大科,分子系统学的研究证据表明它是一个自然类群。前人根据染色体的基数,将蹄盖蕨科划分为3个亚科,但没有得到分子证据的支持;本文依据分子系统学的研究结果,再结合形态特征,将该科重新划分为5个亚科：冷蕨亚科、蹄盖蕨亚科、对囊蕨亚科、双盖蕨亚科和轴果蕨亚科。     

Phylogeny of the family Congiopodidae (Perciformes: Scorpaenoidea), with a proposal of new classification

The phylogenetic relationships of the family Congiopodidae are inferred based on morphological characters. The monophyly of this family is supported by 13 unambiguous apomorphic characters, including four autapomorphies among the superfamily Scorpaenoidea. The Congiopodidae shares 26 apomorphic characters with other scorpaenoid taxa, and these characters are considered to also support the monophyly of the family. Upon completion of the phylogenetic analysis using the characters in 39 transformation series, it was assumed that the family is unambiguously supported by five characters (and also by three and one characters when ACCTRAN and DELTRAN are used, respectively) and is branched into two major clades, including Congiopodus and Alertichthys plus Zanclorhynchus, respectively. Based on the phylogenetic relationships, a new classification, recognizing two subfamilies (Congiopodinae and Zanclorhynchinae) in the family Congiopodidae, is proposed. The genus Perryena, that was recently inferred being closely related to the Tetrarogidae (although many authors included it in the Congiopodidae), is provisionally placed into the Congiopodidae as incertae sedis.     

Different models of tubificid spermatozeugmata

The structure of the spermatozeugmata of different tubificid species belonging to the subfamilies Tubificinae, Limnodriloidinae and Phallodrilinae was compared to the one of Tubifex tubifex. It was concluded that the spermatozeugmata of Tubificoides and Clitellio (Tubificinae) were very similar to the Tubifex ones in having a parallel arrangement of the central fertilizing sperm surrounded by a cortex made of packed atypical spermatozoa. On the contrary, Kaketio ineri and Marcusaedrilus tuber (Limnodriloidinae) and Bathydrilus formosus (Phallodrilinae) show an organization typical for each species but different from that of Tubifex mainly in lacking a double sperm line. A more comprehensive definition of the spermatozeugmata is proposed and more attention to the morphology of the sperm bundles when describing new oligochaete species is suggested, since it is possible to use this information for taxonomic and phylogenetic purposes.     

Phylogenetic analysis of the aquatic Oligochaeta under the principle of parsimony

Phylogenetic relationships between five subfamilies of Tubificidae and ten other families of microdrile oligochaetes were estimated by a Wanger parsimony analysis using PAUP (Phylogenetic Analysis Using Parsimony, by D. L. Swofford). As the apomorph character state is ambiguous for some characters, different assumptions of directionality as well as deletions of some characters are tested in a number of analyses. A general pattern is evident from the study; (1) the majority of the aquatic families are members of a large monophyletic group (the order Tubificida in a somewhat restricted sense) defined by the shared possession of atria (generally with well developed external prostate glands), but the family Tubificidae is paraphyletic within this group; (2) the Enchytraeidae appear to form a second group (the Enchytraeida) together with the exclusively marine Capilloventridae and Randiellidae, all three families characterized by the anterior location of the spermathecae; (3) the Haplotaxidae are a plesiomorph family, which stands out as a branch of its own and constitutes the ancestral part of a group comprising also all the megadriles (the Haplotaxida). However, monophyly of the Haplotaxida is likely only if the haplotaxid octogonadial condition is assumed to be derived from the tetragonadial condition characterizing most microdriles, a situation not envisaged by previous authors. The implications of the parsimony method are briefly discussed.     

基于多个叶绿体基因序列片段重建广义苋科系统发育关系

苋科(Amaranthaceae sensu lato)是石竹目(Caryophyllales)第二大科, 目前被普遍接受的苋科为其广义概念, 含狭义苋科(Amaranthaceae sensu stricto)和藜科(Chenopodiaceae)。然而到目前为止, 藜科是否应作为独立的科还存在争议。此外, 广义苋科内部各亚科之间的系统关系也尚未厘清。对广义苋科所有13个亚科代表类群进行取样(共59种), 基于8个叶绿体序列片段重建其系统发育关系, 并结合分子钟估算, 对该科及其主要分支的起源与分化时间进行推测。结果表明, 广义苋科与狭义苋科都是很好的单系, 但藜科并非单系, 因此不支持藜科在科级水平的地位, 支持广义苋科的观点。除了多节草亚科(Polycnemoideae)之外, 其它亚科的系统位置均得到很好的分辨。分子钟估算结果表明, 广义苋科于白垩纪晚期约69.9 Ma分化出该科的2个主要分支, 且该科在白垩纪-古近纪边界附近时期(约66.0 Ma)可能发生过快速辐射分化事件。     

Phylogeny of the Sympetrinae (Odonata: Libellulidae): further evidence of the homoplasious nature of wing venation

Abstract.  Sympetrinae is the largest subfamily of the diverse dragonfly family Libellulidae. This subfamily, like most libellulid subfamilies, is defined currently by a few wing venation characters, none of which are synapomorphies for the taxon. In this study, we used DNA sequence data from the nuclear locus elongation factor-1α and the mitochondrial loci 16S and 12S rRNA, together with 38 wing venation characters, to test the monophyly of the Sympetrinae and several other libellulid subfamilies. No analysis recovered Sympetrinae as monophyletic, partly because of the position of Leucorrhinia (of the subfamily Leucorrhininae) as a strongly supported sister to Sympetrum (of Sympetrinae) in all analyses. The subfamilies Brachydiplactinae, Leucorrhininae, Trameinae and Trithemistinae were also found not to be monophyletic. Libellulinae was the only subfamily supported strongly as monophyletic. Consistency indices and retention indices of wing venation characters used to define various subfamilies were closer to zero than unity, showing that many of these characters were homoplasious, and therefore not useful for a classification scheme within Libellulidae.     

A phylogenetic analysis of the Orchidaceae: evidence from rbcL nucleotide

Cladistic parsimony analyses of rbcL nucleotide sequence data from 171 taxa representing nearly all tribes and subtribes of Orchidaceae are presented here. These analyses divide the family into five primary monophyletic clades: apostasioid, cypripedioid, vanilloid, orchidoid, and epidendroid orchids, arranged in that order. These clades, with the exception of the vanilloids, essentially correspond to currently recognized subfamilies. A distinct subfamily, based upon tribe Vanilleae, is supported for Vanilla and its allies. The general tree topology is, for the most part, congruent with previously published hypotheses of intrafamilial relationships; however, there is no evidence supporting the previously recognized subfamilies Spiranthoideae, Neottioideae, or Vandoideae. Subfamily Spiranthoideae is embedded within a single clade containing members of Orchidoideae and sister to tribe Diurideae. Genera representing tribe Tropideae are placed within the epidendroid clade. Most traditional subtribal units are supported within each clade, but few tribes, as currently circumscribed, are monophyletic. Although powerful in assessing monophyly of clades within the family, in this case rbcL fails to provide strong support for the interrelationships of the subfamilies (i.e., along the spine of the tree). The cladograms presented here should serve as a standard to which future morphological and molecular studies can be compared.     

Phylogeny of Psephenidae (Coleoptera: Byrrhoidea) based on larval, pupal and adult characters

Abstract.  We conducted the first comprehensive phylogenetic analysis of Psephenidae, based on 143 morphological characters of adults, larvae and pupae and coded for 34 taxa, representing three outgroups and 31 psephenid genera, including four undescribed ones. A strict consensus tree calculated (439 steps, consistency index = 0.45, retention index = 0.75) from the two most-parsimonious cladograms indicated that the monophyly of the family and subfamilies is supported, with the exception of Eubriinae, which is paraphyletic when including Afroeubria . Here a new subfamily, Afroeubriinae ( subfam.n. ), is formally established for Afroeubria . The analysis also indicated that the 'streamlined' larva is a derived adaptive radiation. Here, suprageneric taxonomy and the evolution of some significant characters are discussed. Keys are provided to the subfamilies and genera of Psephenidae considering larvae, adults and pupae.     

Phylogenetic relationships of subfamilies and circumscription of tribes in the family Hesperiidae (Lepidoptera: Hesperioidea)

A comprehensive tribal‐level classification for the world’s subfamilies of Hesperiidae, the skipper butterflies, is proposed for the first time. Phylogenetic relationships between tribes and subfamilies are inferred using DNA sequence data from three gene regions (cytochrome oxidase subunit I‐subunit II, elongation factor‐1α and wingless). Monophyly of the family is strongly supported, as are some of the traditionally recognized subfamilies, with the following relationships: (Coeliadinae + (“Pyrginae” + (Heteropterinae + (Trapezitinae + Hesperiinae)))). The subfamily Pyrginae of contemporary authors was recovered as a paraphyletic grade of taxa. The formerly recognized subfamily Pyrrhopyginae, although monophyletic, is downgraded to a tribe of the “Pyrginae”. The former subfamily Megathyminae is an infra‐tribal group of the Hesperiinae. The Australian endemic Euschemon rafflesia is a hesperiid, possibly related to “Pyrginae” (Eudamini). Most of the traditionally recognized groups and subgroups of genera currently employed to partition the subfamilies of the Hesperiidae are not monophyletic. We recognize eight pyrgine and six hesperiine tribes, including the new tribe Moncini. © The Willi Hennig Society 2008.