Phylogeny of the Acanthocephala based on morphological characters

Only four previous studies of relationships among acanthocephalans have included cladistic analyses, and knowledge of the phylogeny of the group has not kept pace with that of other taxa. The purpose of this study is to provide a more comprehensive analysis of the phylogenetic relationships among members of the phylum Acanthocephala using morphological characters. The most appropriate outgroups are those that share a common early cell-cleavage pattern (polar placement of centrioles), such as the Rotifera, rather than the Priapulida (meridional placement of centrioles) to provide character polarity based on common ancestry rather than a general similarity likely due to convergence of body shapes. The phylogeny of 22 species of the Acanthocephala was evaluated based on 138 binary and multistate characters derived from comparative morphological and ontogenetic studies. Three assumptions of cement gland structure were tested: (i) the plesiomorphic type of cement glands in the Rotifera, as the sister group, is undetermined; (ii) non-syncytial cement glands are plesiomorphic; and (iii) syncytial cement glands are plesiomorphic. The results were used to test an early move of Tegorhynchus pectinarius to Koronacantha and to evaluate the relationship between Tegorhynchus and Illiosentis. Analysis of the data-set for each of these assumptions of cement gland structure produced the same single most parsimonious tree topology. Using Assumptions i and ii for the cement glands, the trees were the same length (length = 404 steps, CI = 0.545, CIX = 0.517, HI = 0.455, HIX = 0.483, RI = 0.670, RC = 0.365). Using Assumption iii, the tree was three steps longer (length = 408 steps, CI = 0.539, CIX = 0.512, HI = 0.461, HIX = 0.488, RI = 0.665, RC = 0.359). The tree indicates that the Palaeacanthocephala and Eoacanthocephala both are monophyletic and are sister taxa. The members of the Archiacanthocephala are basal to the other two clades, but do not themselves form a clade. The results provide strong support for the Palaeacanthocephala and the Eoacanthocephala and the hypothesis that the Eoacanthocephala is the most primitive group is not supported. Little support for the Archiacanthocephala as a monophyletic group was provided by the analysis. Support is provided for the recognition of Tegorhynchus and Illiosentis as distinct taxa, as well as the transfer of T. pectinarius to Koronacantha.     

Regulation of seasonality in the migratory male blackheaded bunting (Emberiza melanocephala)

The present study was carried out on a Palearctic-Indian migratory species, the blackheaded bunting (Emberiza melanocephala), to understand the importance of photoperiodism and circannual rhythms in determining seasonality in changes in body mass and testis size in birds. An initial experiment determined the effects of duration and intensity of light on photoperiodic induction. The birds were exposed to different photoperiods (hours of light:hours of darkness; 11.5L:12.5D, 12L:12D, 12.5L:11.5D and 13L:11D) at the same (approximately 450 lux) light intensity, and to 13L:11D at different light intensities (50-, 100-, 400-, 800- and 1000-lux). The induction and subsequent regression of photoperiodic responses were dependent upon duration and intensity of the light period until these reached threshold. A second experiment investigated if an endogenous seasonal rhythm underlies photoperiodism in buntings. Birds maintained since February on a 8L: 16D photoperiod (a non-inductive short day length invariably used to ensure photosensitivity in photoperiodic species) were subjected periodically to 16L:8D (a long day length), one group every month from mid-March to mid-August. The magnitude of long day response in body mass and testes decreased as the duration of the short days progressed, but testicular response was restored in birds that were exposed to long days in July and August. The birds exposed simultaneously to short, long, and natural day lengths for 32 weeks underwent an induction-regression cycle under long days and natural day lengths, but not under short days in which a decrease in body mass occurred after about 20 weeks. The last experiment examined the importance of latitudinal migration on photoperiodism, by comparing the response to long days of three groups which included birds from populations those were held in the outdoor aviary for 1 or 2 years at 27 degrees N and those immediately arrived from their breeding grounds (approximately 40 degrees N). There was no difference in the photoperiodic induction among the three groups, indicating that neither experience to changing photoperiods during a migratory journey, nor to long photoperiods at breeding grounds, were critical for a subsequent response (initiation-termination-reinitiation) cycle. Taken together, these findings suggest that (1) the blackheaded bunting has its own endogenous timing program, which is regulated by the photoperiod, and (2) the photoperiodic programs of bunting are flexible enough to accommodate variations in the amplitude of environmental cycles. Thus, it appears that photoperiodism has evolved independently of the evolution of migration in this species.     

Phylogeny of Syllidae (Polychaeta) based on morphological data

The phylogeny of Syllidae is assessed in two parsimony analyses of 107 morphological characters. The first analysis included one species of each of the 71 genera of the Syllidae, as well as members of other close families. In the second analysis, 23 poorly known genera were excluded. Character information is based on the examination of available types, additional non-types and newly collected material. Syllidae, except Bollandia Glasby, 1994 is monophyletic. Both analyses supported three of the four traditional subfamilies (Exogoninae, Syllinae and Autolytinae) as monophyletic, whereas Eusyllinae was clearly a polyphyletic group. The genera Anoplosyllis Claparède, 1868, Astreptosyllis Kudenov & Dorsey, 1982 , Streptosyllis Webster & Benedict, 1884, Streptospinigera Kudenov, 1983 and Syllides Örsted, 1845 comprise a well-supported monophyletic group, which we classified as a new subfamily: Anoplosyllinae n. subfam. Our results indicated high levels of homoplasy in the morphological characteristics that traditionally used to differentiate groups, such as the fusion of palps and the presence of nuchal epaulettes. Considering the reproductive modes, schizogamy has appeared twice in the family as the derived condition evolving from epigamy, and Exogoninae may be divided into two monophyletic groups based on the brood system.     

Phylogeny of Dicranophoridae (Rotifera: Monogononta) – a maximum parsimony analysis based on morphological characters

This study presents the first phylogenetic analysis of Dicranophoridae (Rotifera: Monogononta), a species rich rotifer family of about 230 species currently recognized. It is based on a maximum parsimony analysis including 77 selected ingroup and three outgroup taxa and a total of 59 phylogenetically informative morphological characters. Character coding is based on personal investigation of material collected by the authors and an extensive survey of the literature. Apart from covering general body organization, character coding primarily relies on scanning electron microscopic preparations of the mastax jaw elements. Our study suggests monophyly of Dicranophoridae with a clade of Dicranophorus and Dorria as the sister taxon of all other dicranophorid species. Monophyly of Encentrum , the most species rich genus within Dicranophoridae, cannot be demonstrated. Within Dicranophoridae our study identifies the monophyletic taxa Caudosubbasifenestrata, Intramalleata, Praeuncinata and Proventriculata, each based on unambiguous character transformations evolved in their stem lineages. However, resolution within Praeuncinata and Proventriculata is very limited. Although some terminal clades within Praeuncinata and Proventriculata are recognized, basal splits remain obscure. Probably, other characters such as DNA sequence data are needed to further our understanding of phylogenetic relationships within these poorly resolved taxa.     

芦鹀种群中的文化、遗传和形态进化的同时比较

我们比较了芦 (Emberizaschoeniclus)两个亚种组 ,即北部的薄喙亚种组和南部的厚喙亚种组的 10个种群中的文化、遗传和形态变异。使用了四个不同的变异标记物 ,其中两个用来测量文化分化 ,一个用来测量遗传分化 ,即微卫星等位基因的频次 ,一个用来测量种群的形态分化 ,即喙的高度。将遗传分化作为进化时间的尺度 ,我们计算了亚种组间和组内分化指标与所估计的进化率之间的相关性 ,发现只有文化定量指标和遗传分化与种群的形态分化相关 ,而两个文化分化指标之间没有关系 ,文化分化与遗传分化之间也没有关系。使用文化 -定量分化指标 ,发现亚种组间的文化进化率高于亚种内的文化进化率 ,提示鸣唱在防止杂交方面只有微弱的、也许是次要的作用。鸣唱定量特征的变异与微卫星频次相同 ,实际上在自然界中更可能是遗传决定的 ,这可以解释由于分析两个文化变异指标所得出的结果的不一致性。鸣唱的声学特性可能由于栖息地的差异或形态上的限制而发生了演变 ,而文化传播单位 (Meme)的特性可能由于学习鸣唱和文化传播而受到了影响     

Effects of predation risk on diurnal mass dynamics and foraging routines of yellowhammers (Emberiza citrinella)

Theoretical models predict that when having fat reserves iscostly in termsof predation risk, birds should decrease theirlevels of fat reserves inresponse to increased predation risk.I performed an experiment in whichyellowhammers were exposedto a control treatment, where a curtain was movedseveral timesa day, 5 days in a row, and then to a predator treatment, whereaperched, stuffed sparrowhawk appeared when the curtain was moved,5 days ina row. Between the two treatments were 2 days withoutany experimentaltreatment. The birds were expected to decreasein mass, and/or to change thedaily trajectory of mass increasein response to increased predation risk.Yellowhammers decreasedin morning mass and evening mass in response to boththe movingcurtain and the sparrowhawk compared to an untreated day beforethestart of the experiment. However, the response to both treatmentswas not thesame; in the sparrowhawk treatment the birds waitedlonger before resumingfeeding and lost more weight after eachexposure as compared to the curtaintreatment. This loss wasregained, and yellowhammers increased their intakerate. Dueto that, they reduced, although not significantly, the timespentfeeding under predation risk. A reduction in the timespent feeding underpredation risk reduces the time exposedto predators. However, if an increasein intake rate also incursa decrease in vigilance, this might increasepredation risk.The results of this study, together with other studies,indicatethat for yellowhammers a reduction in time exposed to predatorsmightbe more important for survival than a reduction in bodymass.     

Spatial and Temporal Distribution of Song in the Yellowhammer Emberiza citrinella

The temporal and spatial distribution of song was studied in a population of yellowhammers Emberiza citrinella. Song was most frequent during the breeding season, and within the breeding season during the fertile period of both first, second, and replacement clutches. Song activity peaked at sunrise and sunset. During the fertile period most singing took place in the central parts of the territory. Song post heights peaked during the fertile period, and more song posts lacked foliage at that time. Intrusions by male conspecifics peaked in the fertile period and in territories where males sang relatively little. Song activity and mate guarding were strongly positively correlated. Song volume was loud and song was thus apparently used in long-distance communication. These observations are in accordance with a male deterrence hypothesis, suggesting that males sing to deter neighbouring males from trespassing during the fertile period of their mate. A female attraction hypothesis, suggesting that males sing to attract neighbouring females and thereby obtain extra-pair copulations, and a female reproduction hypothesis, suggesting that males sing to start the female reproductive cycle, were partly supported by observations.     

Phylogeny of the Calliergonaceae (Bryophyta) based on molecular and morphological data

Phylogeny of the Calliergonaceae is reconstructed based on nuclear and chloroplast sequence data, and morphology. Depending on treatment of insertions and deletions, the total number of informative characters was 194 or 163. The study yielded good support for two major clades, one with Hamatocaulis, Scorpidium, and possibly Hygrohypnum ochraceum (Wils.) Loeske, and one with Calliergon, Loeskypnum, Straminergon, and Warnstorfia. Inclusion of H. ochraceum in the ingroup increased tree length, markedly decreased consistency and retention indices, and decreased support for the structure of the Hamatocaulis-Scorpidium clade, and its position within the family is challenged. When H. ochraceum was excluded, good support is found for the genera Hamatocaulis and Scorpidium. Within the other major subclade the monophyly of a clade with Loeskypnum, Straminergon, and Warnstorfia, of a portion of Calliergon, and of Warnstorfia fluitans plus W. pseudostraminea are well supported.     

Phylogeny of the millipede genus Sphaeriodesmus Peters, 1864 (Polydesmida: Sphaeriodesmidae) based on morphological characters

In order to understand the evolutionary relationships among the species encompassed within the genus Sphaeriodesmus Peters, 1864, a cladistic analysis including 63 species was conducted. Ninety-five morphological characters were used for the phylogenetic reconstruction. The results suggested that the current composition of the genus Sphaeriodesmus does not circumscribe a monophyletic group; instead, the genera Eusphaeriodesmus, Colobodesmus, and Proeilodesmus are here synonymized under Sphaeriodesmus. Although raw morphological data had suggested the genus Lophocyclus as the sister taxon of Sphaeriodesmus, the phylogenetic analysis under implied weight identified the genus Cyphodesmus as the taxon most closely related to Sphaeriodesmus. Sphaeriodesmus isolatus Chamberlin, 1940 is a subjective synonym of Sphaeriodesmus conformans Chamberlin, 1925. The putative subdivisions previously proposed within Sphaeriodesmus do not hold as monophyletic either. Low stability was observed concerning the higher-level phylogenetic relationships of Sphaeriodesmus. Sphaeriodesmus crucis (Loomis, 1974), S. mecistonyx (Hoffman, 1990), and S. triramus (Kraus, 1954) are new combinations.     

Phylogeny of Aphroditiformia (Polychaeta) based on molecular and morphological data

The phylogeny of Aphroditiformia, benthic polychaetes carrying dorsal elytra, is assessed from nuclear 18S rDNA, mitochondrial cytochrome c oxidase subunit I (COI), and 31 morphological characters. Two non-elytrabearing taxa, Palmyra and Pisione, are included to assess their relationship to the elytrabearers. The data are analysed both separately and combined, with parsimony, maximum likelihood and Bayesian analyses. In total, 19 terminal taxa are examined, including 12 elytrabearing taxa from all scale-worm groups, Palmyra, Pisione, and five outgroup taxa. The results show that Palmyra and Pisione are nested within Aphroditiformia. Palmyra is sister to Aphrodita, and both Pisione and Pholoe are positioned within Sigalionidae, suggesting that both family names Pisionidae and Pholoidae should be treated as junior synonyms of Sigalionidae.     

Environmental and hormonal control of vernal migration in redheaded bunting (Emberiza bruniceps)

This paper reviews the factors and mechanisms which result in the development of the metabolic state characteristic of migration with special reference to a palaeotropic migrant the redheaded bunting,Emberiza bruniceps. Changes in climatic conditions and food supply act as proximate triggers of migratory behaviour in partial migrants. Typical migrants like buntings use daylength as a cue but the exact mechanism of how photoperiodic information is translated in terms of migratory events is still not known. Almost entirely the photoperiodic effects have been explained on the basis of the involvement of hypothalamo/hypophyseal system. We feel mechanism(s) other than those acting through neuroendocrine system may be equally important. Furthermore the role of temperature has not been adequately explored so far. Our observations indicate the possibility that redheaded buntings might integrate the information received from photoperiod with environmental temperature (and other factors?) resulting in the development of migratory state. The physiological control of avian migration is much less understood. Majority of papers have centered around the ‘gonadal hypothesis’ of Rowan supporting or contradicting it without providing conclusive evidence. Pituitary prolactin has also been shown to be implicated although the mechanism of action is only speculative. Conclusive evidence for the involvement of thyroid hormones (thyroxine, T4; triiodothyronine, T3) in the physiological timing of migration has been produced attributing independent roles to T4 and T3. It is suggested that seasonal variation in peripheral conversion of T4 to T3 could serve as an effective strategy to render available the required thyroid hormones T4 and/or T3 during different phases of the year thus accounting for the metabolic switch over from T4-dependent moult to T3-dependent migratory fat deposition and zugunruhe and also ensuring preclusion of simultaneous occurrence of these mutually incompatible events. Considering that the number of environmental and physiological factors influence this mechanism and considering that thyroid hormone molecule has been put to a wide range of usage during the course of evolution the mechanism(s) of peripheral conversion of T4-T3 may assume great flexibility and have selective value-especially in migration which is known to have evolved several times in diverse avian families. The attractiveness of this hypothesis lies in the fact that it has potential to explain the both physiological development of the metabolic state of migration and at the same time the physiological timing of migration not only with respect to the cycle of environment but also with respect to other conflicting seasonal events (moult and reproduction).     

Phylogeny of Tunicata inferred from molecular and morphological characters

The phylogeny of the Tunicata was reconstructed using molecular and morphological characters. Mitochondrial cytochrome oxidase I (cox1) and 18S rDNA sequences were obtained for 14 and 4 tunicate species, respectively. 18S rDNA sequences were aligned with gene sequences obtained from GenBank of 57 tunicates, a cephalochordate, and a selachian craniate. Cox1 sequences were aligned with the sequence of two ascidians and a cephalochordate obtained from GenBank. Traditional, morphological, life history, and biochemical characters of larval and adult stages were compiled from the literature and analyzed cladistically. Separate and simultaneous parsimony analyses of molecular and morphological data were carried out. Aplousobranch ascidians from three different families were included in a molecular phylogenetic analysis for the first time. Analysis of the morphological, life history, and biochemical characters results in a highly unresolved tree. Aplousobranchiata form a strongly supported monophylum in the analysis of the 18S rDNA data, the morphological data, and the combined data set. Cionidae is not included in the Aplousobranchiata but nests within the Phlebobranchiata. Appendicularia (=Larvacea) nest within the 'Ascidiacea' as the sister taxon of Aplousobranchiata in the parsimony analysis of the 18S rDNA data and the combined analysis. A potential morphological synapomorphy of Aplousobranchiata plus Appendicularia is the horizontal orientation of the larval tail. In the 18S rDNA and the combined analysis, Thaliacea is included in the 'Ascidiacea' as the sister group to Phlebobranchiata. Pyrosomatida is found to be the sister taxon to the Salpidae in analyses of 18S rDNA and combined data, whereas the analysis of the morphological data recovers a sister group relationship between Doliolidae and Salpidae. Results of cox1 analyses are incongruent with both the 18S rDNA and the morphological phylogenies. Cox1 sequences may evolve too rapidly to resolve relationships of higher tunicate taxa. However, the cox1 data may be useful at lower taxonomic levels.     

Phylogeny of benthic Phyllodocidae (Polychaeta) based on morphological and molecular data

A combined molecular (18S rDNA, 28S rDNA, 16S rDNA and COI) and morphological analysis of the benthic phyllodocids is presented for the first time. Nineteen phyllodocids and two outgroup taxa are assessed using parsimony, maximum likelihood and Bayesian analyses. We demonstrate high degrees in homoplasy in the traditionally used morphological phyllodocid characters, and show that all the three current subfamilies Phyllodocinae, Eteoninae and Notophyllinae are non-monophyletic. The genera Eulalia, Eumida, Protomystides, Pseudomystides, Pterocirrus and Sige form a well-supported group, as does Mystides and Nereiphylla. Another clade with strong support includes Eteone and Paranaitis, although with Eteone nested within a paraphyletic Paranaitis. The relationship between these two taxa indicate that the unusual arrangement of modified cirri on the first segments in Eteone is due to a fusion of segment 1 and 2 where the cirri of segment 1 have been reduced. Eulalia is non-monophyletic and should be split, minimally into two groups. Our results are ambiguous regarding the ancestral phyllodocid condition of absence-presence of median antenna or nuchal papilla and uniramous or biramous parapodia, but shows that the absence of cirri on segment 3 (previously an apomorphy, for e.g., Mystides, Pseudomystides and Hesionura) is maximally homoplastic.     

Phylogeny and biosystematics ofPseudomonotes (Dipterocarpaceae) based on molecular and morphological data

The placement of a recently discovered South American monotypic genus,Pseudomonotes tropenbosii, in subfam.Monotoideae (Dipterocarpaceae) extends the geographical range of the subfamily from Africa to the Neotropics. Although morphological and anatomical evidence suggest similarities betweenPseudomonotes andMonotes, the close alliance of these two genera was questionable due to their disjunct distribution and a lack of phylogenetic analysis. In the present study, we reconstructed the phylogeny ofPseudomonotes and other putatively related taxa usingrbcL sequence data. The analysis ofrbcL sequences of 20 taxa belonging to 15 genera and eight families recovered a single most parsimonious tree. The genusSarcolaena (Sarcolaenaceae) formed a clade sister to the monophyleticDipterocarpaceae clade.Monotes andPseudomonotes formed a strongly supported group, sister to the monophyletic clade withPakaraimaea and the remaining Asiatic dipterocarp species studied. The study strongly supports the placement ofPseudomonotes within subfam.Monotoideae of theDipterocarpaceae.     

Phylogeny of Isatis (Brassicaceae) and allied genera based on ITS sequences of nuclear ribosomal DNA and morphological characters

Systematics of the genus Isatis (Brassicaceae) is difficult and controversial, and previous studies were based solely on morphological characters. Sequence variation of the internal transcribed spacer (ITS) regions and the 5.8S gene of nuclear ribosomal DNA (nrDNA) were analyzed using parsimony and Bayesian methods. Twenty-eight taxa of Isatis and related genera of the tribe Isatideae were sampled, including 20 Isatis species representing almost all major morphological lineages, all three species of Pachypterygium, two of nine species of Sameraria, and monospecific Boreava, Myagrum, and Tauscheria. Two well-supported clades were resolved in the ITS tree, and they demonstrate the artificiality of the present delimitation of the tribe. One clade includes I. emarginata, I. minima, I. trachycarpa, P. brevipes, P. multicaule, P. stocksii, and T. lasiocarpa. The second clade includes I. buschiana, the polymorphic I. cappadocica with five subspecies, I. gaubae, I. kotschyana, I. leuconeura, I. pachycarpa, I. takhtajanii, I. tinctoria, and S. armena. Pachypterygium is polyphyletic and, together with Boreava, Sameraria, and Tauscheria, all are nested within Isatis. This study is a continuation of our recent systematic survey based on seed-coat microsculpturing ( Moazzeni et al., 2007. Flora 202, 447–454) and reveals that fruit characters mapped onto the molecular tree show considerable convergence. The reliance on fruit characters alone in the delimitation of genera may well lead to erroneous phylogenetic results and thus to incorrect taxonomic conclusions.     

Daily light regulates seasonal responses in the migratory male redheaded bunting (Emberiza bruniceps)

This study analyzed the role of day length in regulation of seasonal body fattening and testicular growth in a latitudinal Palaearctic-Indian migrant, the redheaded bunting (Emberiza bruniceps). When exposed to increasing photoperiods (hours of light: hours of darkness; 11.5L:12.5D, 12L:12D, 12.5L:11.5D, 13L:11D, 14L:10D, and 18L:6D) for 9-12 weeks, buntings responded in a photoperiod-dependent manner and underwent growth and regression cycle under photoperiods of > or =12 hr per day. Also, the response to a long photoperiod of birds that were held under natural photoperiods at 27 degrees N for 2 years was similar to those who arrived the same year from their breeding grounds ( approximately 40 degrees N), suggesting that the experience of higher amplitude day-night (light-dark, LD) cycles during migratory and breeding seasons were not critical for the subsequent response (initiation-termination-reinitiation) cycle. Another experiment examined entrainment of the circadian photoperiodic rhythm in buntings by subjecting them to T=24+/-2 hr LD-cycles with 8 hr photophase and to T=22 and 24 hr with 11 hr photophase. The results showed a reduction in critical day length under T=22 hr LD-cycle. In the last experiment, we constructed an action spectrum for photoperiodic induction by exposing birds for 4.5 weeks to 13L:11D of white (control), blue (450 nm), or red (640 nm) light at irradiances ranging from 0.028 to 1.4 W m(-2). The threshold light irradiance for photoinduction was about 10-fold higher for blue light, than for red and white lights. These results conclude that the daily light of the environment regulates the endogenous program that times seasonal responses in body fattening and testicular cycles of the redheaded bunting.     

Phylogeny of three species groups of Rhinocricus Karsch, 1881 based on morphological characters (Diplopoda,Spirobolida, Rhinocricidae)

Rhinocricus Karsch, 1881 has 207 species occurring mainly in the Americas, and more than 60 of them were described from Brazil. The genus was proposed base     

Investigations of photoperiodically induced fattening in migratory blackheaded bunting (Emberiza melanocephala)(Ayes)

The body fattening and weight gain preceding vernal migration in birds is timed by a set of environmental factors of which daylength is predominant. However, the mechanism(s) by which these events is determined is poorly understood. Previous investigations on a photoperiodic migratory species, the blackheaded bunting ( Emberiza melanocephala ), indicate the involvement of a light-sensitive circadian rhythm during initiation of fat deposition and body weight gain. This communication presents data from another set of experiments aimed to characterize further the mechanism(s) of fat deposition in the same species.
Groups of photosensitive, unstimulated and stimulated birds were subjected to transfer and superimposition experiments for 30 days. While the former set included shifting of long-day (LD) birds to DD, SD (short days), DD/LD and SD/LD, in the latter a 90-minute bright light was superimposed at two different times of the day during the dim-green lighted phase 15L:9D of varying intensity. Birds were weighed at the beginning and at the end of experiments. Those in transfer cycles were also weighed at 10-day intervals. The results suggest that the premigratory body fattening and weight gain in blackheaded buntings is light dependent and timed by environmental daylength in accordance with the photosensitive endogenous circadian rhythm (ECR). They also show that the photoperiodic responses in birds in general are mediated by circadian rhythm(s).