Wide-band tracheids (WBTs) of photosynthetic and non-photosynthetic stems in species of Cactaceae

ARRUDA, E. AND G. F. A. MELO-DE-PINNA (Departamento de Botanica, Instituto de Biociencias. Universidade de Sao Paulo, Rua do Matao, travessa 14, Cidade Universitaria, Butanta, Caixa Postal 11461, 05422-970. Sao Paulo, SP, Brasil). Wide-band tracheids (WBTs) of the photosynthetic and non-photosynthetic stems in species of Cactaceae. J. Torrey Bat. Soc. 137: 16-29. 2010.-The absence of WBTs and wood polymorphisms in some species of the Caryophyllales may be related to the particular area of plant analyzed. The present research has the objective of studying the photosynthetic and non-photosynthetic stems of different species and stages of differentiation to register wood polymorphisms and to understand the distribution and occurrence of WBTs. Wood polymorphism was observed in the non-photosynthetic stern of young and adult plants of Opuntioideae and Cactoideae and is also found in the photosynthetic stem of young plants of some species of Cactoideae. Cactoideae present WBT/fibrous dimorphic wood that can be related to cambial variation associated with growth habits and plant development. As expected, in the photosynthetic stem of the adult columnar cacti the wood is monomorphic fibrous in which WBTs were not found. This wood contains a great amount of fibers due to necessity of the mechanical support. In contrast, the globular species do not possess fibers in this area of the stem in either adult or young plants. Opuntia monacantha Haw. had non-fibrous wood in which WBTs were observed in the axial system and in the inner parts of the rays. Fiber clusters were present in the axial system. This wood represents a variation in the wood types described for Opuntioideae. Also, in O. monacantha, cells similar to the WBTs were observed in the pith, which can be interpreted as variation in the morphogenic processes during the ontogeny of the plant, probably a case of homeosis. Monomorphic fibrous wood without WBTs was found along the entire stem of Pereskia bahiensis Gurke. This feature has been observed in other pereskias, and in addition to the others, indicates its proximity to the ancestral cacti.

Generic relationships and dating of lineages in Winteraceae based on nuclear (ITS) and plastid (rpS16 and psbA-trnH) sequence data

Phylogenetic analyses of representative species from the five genera of Winteraceae (Drimys, Pseudowintera, Takhtajania, Tasmannia, and Zygogynum s.l.) were performed using ITS nuclear sequences and a combined data-set of ITS + psbA-trnH + rpS16 sequences (sampling of 30 and 15 species, respectively). Indel informativity using simple gap coding or gaps as a fifth character was examined in both data-sets. Parsimony and Bayesian analyses support the monophyly of Drimys, Tasmannia, and Zygogynum s.l., but do not support the monophyly of Belliolum, Zygogynum s.s., and Bubbia. Within Drimys, the combined data-set recovers two subclades. Divergence time estimates suggest that the splitting between Drimys and its sister clade (Pseudowintera + Zygogynum s.l.) occurred around the end of the Cretaceous; in contrast, the divergence between the two subclades within Drimys is more recent (15.5-18.5 MY) and coincides in time with the Andean uplift. Estimates suggest that the earliest divergences within Winteraceae could have predated the first events of Gondwana fragmentation. (C) 2009 Elsevier Inc. All rights reserved.

Evidence for the conspecificity of Palisada papillosa with P. perforata (Ceramiales, Rhodophyta) from the western and eastern Atlantic Ocean on the basis of morphological and molecular analyses

Morphological and molecular studies were carried out on Palisada papillosa and P. perforata from the Canary Islands (type locality of P. perforata), Mexico and Brazil. The two species have been distinguished by features of their external morphology such as size and degree of compactness of the thalli, presence or absence of arcuate branches, branching pattern and basal system. A detailed morphological comparison between these taxa showed that none of the vegetative anatomical or reproductive characters was sufficient to separate these species. The presence or absence of cortical cells in a palisade-like arrangement, also previously used to. distinguish these species, is not applicable. The species present all characters typical of the genus, and both share production of the first pericentral cell underneath the basal cell of the trichoblast, production of two fertile pericentral cells (the second and the third additional, the first remaining sterile), spermatangial branches produced from one of two laterals on the suprabasal cell of trichoblasts, and the procarpbearing segment with four pericentral cells. Details of the procarp are described for the species for the first time. The phylogenetic position of these species was inferred by analysis of the chloroplast-encoded rbcL gene sequences from 39 taxa, using one other Rhodomelacean taxon and two Ceramiaceae as outgroups. Relationships within the clade formed by P. papillosa and P. perforata have not been resolved due to the low level of genetic variation in their rbcL sequences (0-0.4%). Considering this and the morphological similarities, we conclude that P. papillosa is a taxonomic synonym of P. perforata. The phylogenetic analyses also supported the nomenclatural transfer of two species of Chondrophycus to Palisada, namely, P. patentiramea (Montagne) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov. and P. thuyoides (Kutzing) Cassano, Senties, Gil-Rodriguez & M.T. Fujii comb. nov.

Gracilariopsis mclachlanii sp nov and Gracilariopsis persica sp nov of the Gracilariaceae (Gracilariales, Rhodophyceae) from the Indian Ocean

Two new species of Gracilariopsis from the Indian Ocean are proposed-Gracilariopsis (Gp.) mclachlanii Buriyo, Bellorin et M. C. Oliveira sp. nov. from Tanzania and Gracilariopsis persica Bellorin, Sohrabipour et E. C. Oliveira sp. nov. from Iran-based on morphology and DNA sequence data (rbcL gene and SSU rDNA). Both species fit the typical features of Gracilariopsis: axes cylindrical throughout, freely and loosely ramified up to four orders, with an abrupt transition in cell size from medulla to cortex, cystocarps lacking tubular nutritive cells and superficial spermatangia. Nucleotide sequence comparisons of rbcL and SSU rDNA placed both species into the Gracilariopsis clade as distinct species from all the accepted species for this genus, forming a deeply divergent lineage together with some species from the Pacific. The new species are very difficult to distinguish on morphological grounds from other species of Gracilariopsis, stressing the importance of homologous molecular marker comparisons for the species recognition in this character-poor genus.

Analysis of a hyper-diverse seed dispersal network: modularity and underlying mechanisms

Mutualistic interactions involving pollination and ant-plant mutualistic networks typically feature tightly linked species grouped in modules. However, such modularity is infrequent in seed dispersal networks, presumably because research on those networks predominantly includes a single taxonomic animal group (e.g. birds). Herein, for the first time, we examine the pattern of interaction in a network that includes multiple taxonomic groups of seed dispersers, and the mechanisms underlying modularity. We found that the network was nested and modular, with five distinguishable modules. Our examination of the mechanisms underlying such modularity showed that plant and animal trait values were associated with specific modules but phylogenetic effect was limited. Thus, the pattern of interaction in this network is only partially explained by shared evolutionary history. We conclude that the observed modularity emerged by a combination of phylogenetic history and trait convergence of phylogenetically unrelated species, shaped by interactions with particular types of dispersal agents.

The evolution of jumping performance in anurans: morphological correlates and ecological implications

We investigated the evolution of anuran locomotor performance and its morphological correlates as a function of habitat use and lifestyles. We reanalysed a subset of the data reported by Zug (Smithson. Contrib. Zool. 1978; 276: 1-31) employing phylogenetically explicit statistical methods (n = 56 species), and assembled morphological data on the ratio between hind-limb length and snout-vent length (SVL) from the literature and museum specimens for a large subgroup of the species from the original paper (n = 43 species). Analyses using independent contrasts revealed that classifying anurans into terrestrial, semi-aquatic, and arboreal categories cannot distinguish between the effects of phylogeny and ecological diversification in anuran locomotor performance. However, a more refined classification subdividing terrestrial species into `fossorials` and `non-fossorials`, and arboreal species into `open canopy`, `low canopy` and `high canopy`, suggests that part of the variation in locomotor performance and in hind-limb morphology can be attributed to ecological diversification. In particular, fossorial species had significantly lower jumping performances and shorter hind limbs than other species after controlling for SVL, illustrating how the trade-off between burrowing efficiency and jumping performance has resulted in morphological specialization in this group.

Mitochondrial DNA Diversity of Orchid Bee Euglossa fimbriata (Hymenoptera: Apidae) Populations Assessed by PCR-RFLP

Euglossa fimbriata is a euglossine species widely distributed in Brazil and occurring primarily in Atlantic Forest remnants. In this study, the genetic mitochondrial structure of E. fimbriata from six Atlantic Forest fragments was studied by RFLP analysis of three PCR-amplified mtDNA gene segments (16S, COI-COII, and cyt b). Ten composite haplotypes were identified, six of which were exclusive and represented singleton mitotypes. Low haplotype diversity (0.085-0.289) and nucleotide diversity (0.000-0.002) were detected within samples. AMOVA partitioned 91.13% of the overall genetic variation within samples and 8.87% (I center dot(st) = 0.089; P < 0.05) among samples. Pairwise comparisons indicated high levels of differentiation among some pairs of samples (I center dot(st) = 0.161-0.218; P < 0.05). These high levels indicate that these populations of E. fimbriata, despite their highly fragmented landscape, apparently have not suffered loss of genetic variation, suggesting that this particular population is not currently endangered.

Genetic structure of Partamona helleri (Apidae, Meliponini) from Neotropical Atlantic rainforest

Stingless bees of the genus Partamona are distributed from southern Mexico to southern Brazil. This genus has been subject to different approaches to solve questions concerning general biology, taxonomy, systematics and biogeography, but population studies applying molecular techniques are inexistent. We analyzed the genetic structure of P. helleri across its geographic distribution along the coastal Atlantic tropical rainforest in Brazil. Ten mtDNA haplotypes were observed in 47 colonies of P. helleri of which some were exclusive and others shared among geographic sub-groups. Statistical analysis showed high genetic differentiation between geographic areas sampled. Fragmentation of the Atlantic forest during Pleistocene glaciations is discussed as a possible cause of the present haplotype distribution and frequency.

Covariance structure in the skull of Catarrhini: a case of pattern stasis and magnitude evolution

The study of the genetic variance/covariance matrix (G-matrix) is a recent and fruitful approach in evolutionary biology, providing a window of investigating for the evolution of complex characters. Although G-matrix studies were originally conducted for microevolutionary timescales, they could be extrapolated to macroevolution as long as the G-matrix remains relatively constant, or proportional, along the period of interest. A promising approach to investigating the constancy of G-matrices is to compare their phenotypic counterparts (P-matrices) in a large group of related species; if significant similarity is found among several taxa, it is very likely that the underlying G-matrices are also equivalent. Here we study the similarity of covariance and correlation structure in a broad sample of Old World monkeys and apes (Catarrhini). We made phylogenetically structured comparisons of correlation and covariance matrices derived from 39 skull traits, ranging from between species to the superfamily level. We also compared the overall magnitude of integration between skull traits (r(2)) for all Catarrhim genera. Our results show that P-matrices were not strictly constant among catarrhines, but the amount of divergence observed among taxa was generally low. There was significant and positive correlation between the amount of divergence in correlation and covariance patterns among the 30 genera and their phylogenetic distances derived from a recently proposed phylogenetic hypothesis. Our data demonstrate that the P-matrices remained relatively similar along the evolutionary history of catarrhines, and comparisons with the G-matrix available for a New World monkey genus (Saguinus) suggests that the same holds for all anthropoids. The magnitude of integration, in contrast, varied considerably among genera, indicating that evolution of the magnitude, rather than the pattern of inter-trait correlations, might have played an important role in the diversification of the catarrhine skull. (C) 2009 Elsevier Ltd. All rights reserved.

The Y Chromosome of the Atelidae Family (Platyrrhini): Study by Chromosome Microdissection

In order to study the intergeneric variability of the Y chromosome, we describe the hybridization of the Y chromosome of Brachyteles arachnoides, obtained by microdissection, to metaphases of Ateles belzebuth marginatus, Lagothrix lagothricha, and Alouatta male specimens. Brachyteles arachnoides (Atelinae) has 62 chromosomes and a very small Y chromosome. Our results showed that the Brachyteles arachnoides Y chromosome probe hybridized to Lagothrix lagothricha metaphases yielding one hybridization signal on only the tiny Y chromosome, and when hybridized with Ateles belzebuth marginatus metaphases it yielded one hybridization signal on two thirds of the small acrocentric Y chromosome. However, no hybridization signal was observed in Alouatta metaphases (subfamily Alouattinae), a closely related genus in the Atelidae family. Furthermore, our data support a close phylogenetic relationship among Brachyteles, Ateles, and Lagothrix and their placement in the Atelinae subfamily, but exclude Alouatta from this group indicating its placement as basal to this group. Copyright (C) 2009 S. Karger AG, Basel

Cladistic analysis of continuous modularized traits provides phylogenetic signals in Homo evolution

Evolutionary novelties in the skeleton are usually expressed as changes in the timing of growth of features intrinsically integrated at different hierarchical levels of development(1). As a consequence, most of the shape- traits observed across species do vary quantitatively rather than qualitatively(2), in a multivariate space(3) and in a modularized way(4,5). Because most phylogenetic analyses normally use discrete, hypothetically independent characters(6), previous attempts have disregarded the phylogenetic signals potentially enclosed in the shape of morphological structures. When analysing low taxonomic levels, where most variation is quantitative in nature, solving basic requirements like the choice of characters and the capacity of using continuous, integrated traits is of crucial importance in recovering wider phylogenetic information. This is particularly relevant when analysing extinct lineages, where available data are limited to fossilized structures. Here we show that when continuous, multivariant and modularized characters are treated as such, cladistic analysis successfully solves relationships among main Homo taxa. Our attempt is based on a combination of cladistics, evolutionary- development- derived selection of characters, and geometric morphometrics methods. In contrast with previous cladistic analyses of hominid phylogeny, our method accounts for the quantitative nature of the traits, and respects their morphological integration patterns. Because complex phenotypes are observable across different taxonomic groups and are potentially informative about phylogenetic relationships, future analyses should point strongly to the incorporation of these types of trait.

Morphology and phylogenetic relationships of a remarkable new genus and two new species of Neotropical freshwater stingrays from the Amazon basin (Chondrichthyes: Potamotrygonidae)

The morphology and phylogenetic relationships of a new genus and two new species of Neotropical freshwater stingrays, family Potamotrygonidae, are investigated and described in detail. The new genus, Heliotrygon, n. gen., and its two new species, Heliotrygon gomesi, n. sp. (type-species) and Heliotrygon rosai, n. sp., are compared to all genera and species of potamotrygonids, based on revisions in progress. Some of the derived features of Heliotrygon include its unique disc proportions (disc highly circular, convex anteriorly at snout region, its width and length very similar), extreme subdivision of suborbital canal (forming a complex honeycomb-like pattern anterolaterally on disc), stout and triangular pelvic girdle, extremely reduced caudal sting, basibranchial copula with very slender and acute anterior extension, and precerebral and frontoparietal fontanellae of about equal width, tapering very little posteriorly. Both new species can be distinguished by their unique color patterns: Heliotrygon gomesi is uniform gray to light tan or brownish dorsally, without distinct patterns, whereas Heliotrygon rosai is characterized by numerous white to creamy-white vermiculate markings over a light brown, tan or gray background color. Additional proportional characters that may further distinguish both species are also discussed. Morphological descriptions are provided for dermal denticles, ventral lateral-line canals, skeleton, and cranial, hyoid and mandibular muscles of Heliotrygon, which clearly corroborate it as the sister group of Paratrygon. Both genera share numerous derived features of the ventral lateral-line canals, neurocranium, scapulocoracoid, pectoral basals, clasper morphology, and specific patterns of the adductor mandibulae and spiracularis medialis muscles. Potamotrygon and Plesiotrygon are demonstrated to share derived characters of their ventral lateral-line canals, in addition to the presence of angular cartilages. Our morphological phylogeny is further corroborated by a molecular phylogenetic analysis of cytochrome b based on four sequences (637 base pairs in length), representing two distinct haplotypes for Heliotrygon gomesi. Parsimony analysis produced a single most parsimonious tree revealing Heliotrygon and Paratrygon as sister taxa (boot-strap proportion of 70%), which together are the sister group to a clade including Plesiotrygon and species of Potamotrygon. These unusual stingrays highlight that potamotrygonid diversity, both in terms of species composition and undetected morphological and molecular patterns, is still poorly known.

Characterizations of juvenile stages of some semaeostome Scyphozoa (Cnidaria), with recognition of a new family (Phacellophoridae)

Phacellophora camtschatica has long been assigned to the semaeostome scyphozoan family Ulmaridae. Early stages (scyphistomae, strobilae, ephyrae, postephyrae, and young medusae) of the species were compared with those of several other semaeostomes currently assigned to Ulmaridae, Pelagiidae, and Cyaneidae. Juveniles of P. camtschatica did not strictly conform with characters of those of any of these families, and appeared intermediate between Cyaneidae and Ulmaridae. A new family, Phacellophoridae, is proposed to accommodate P. camtschatica.

A new genus and new species of fan worms (Polychaeta: Sabellidae) from Atlantic and Pacific Oceans-the formal treatment of taxon names as explanatory hypotheses

Members of Parasabella minuta Treadwell, 1941, subsequently moved to Perkinsiana, were collected during a survey of rocky intertidal polychaetes along the state of Sao Paulo, Brazil. Additional specimens, which are referred to two new species, were also found in similar habitats from the Bocas del Toro Archipelago, Caribbean Panama, and Oahu Island, Hawaii. A phylogenetic analysis of Sabellinae, including members of P. minuta and the two new species, provided justification for establishing a new generic hypothesis, Sabellomma gen. nov., for these individuals. Formal definitions are also provided for Sabellomma minuta gen. nov., comb. nov., S. collinae gen. nov., spec. nov., and S. harrisae gen. nov., spec. nov., along with descriptions of individuals to which these hypotheses apply. The generic name Aracia nom. nov., is provided to replace Kirkia Nogueira, Lopez and Rossi, 2004, pre-occupied by a mollusk.

Taxonomic review of Haliclystus antarcticus Pfeffer, 1889 (Stauromedusae, Staurozoa, Cnidaria), with remarks on the genus Haliclystus Clark, 1863

Difficulties concerning the taxonomy of stauromedusae are long known, and there is a clear need for taxonomic revision of the genus Haliclystus, as well as the reevaluation of some species. Haliclystus antarcticus Pfeffer, 1889 is recorded from Admiralty Bay, King George Island, Antarctic Peninsula. Due to the lack of detailed information on this species, we provide a redescription, presenting new data on the cnidome, morphometry, geographical distribution and intraspecific variation. Based on these characters, we propose that our specimens and Haliclystus auricula from Chile and Argentina are synonymous and should be classified as H. antarcticus. We also review the worldwide distribution of the genus Haliclystus Clark, 1863 and discuss taxonomic issues, concluding that some characters traditionally used in the taxonomy of the group should be used cautiously.