The aye-aye (Daubentonia madagascariensis) found in the eastern rainforest of Madagascar

In the course of a study on the ecology of nocturnal lemurs several aye-aye (Daubentonia madagascariensis) were seen in the eastern rainforest of Madagascar near Perinet. These observations of the aye-aye in a forest of higher altitude suggest a still much wider distribution of this species than previously thought.     

The re-stocking of captive-bred ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve, Madagascar: methodology and recommendations

Since November 1997 the Madagascar Fauna Group has released 13 captive-bred black and white ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve in eastern Madagascar. The release programme has three major aims: (1) to assess the ability of captive-bred V. v. variegata to adapt to life in their natural habitat; (2) to investigate the contribution that such a release programme can make to reinforcing the existing small wild population of V. v. variegata in Betampona; and (3) to contribute to the long-term protection and conservation of the reserve. Criteria for the selection of release candidates, veterinary screening and pre-release experience in naturalistic environments are described and discussed. Methods for post-release monitoring of health and behaviour are covered in detail. The importance of considering the social dynamics of the species involved is emphasised. The survival of five of the releasees, plus successful reproduction and integration with the wild population have led to the conclusion that the release was a success.     

Cyberkelp: an integrative approach to the modelling of flexible organisms

Biomechanical models come in a variety of forms: conceptual models; physical models; and mathematical models (both of the sort written down on paper and the sort carried out on computers). There are model structures (such as insect flight muscle and the tendons of rats' tails), model organisms (such as the flying insect, Manduca sexta), even model systems of organisms (such as the communities that live on wave-swept rocky shores). These different types of models are typically employed separately, but their value often can be enhanced if their insights are integrated. In this brief report we explore a particular example of such integration among models, as applied to flexible marine algae. A conceptual model serves as a template for the construction of a mathematical model of a model species of giant kelp, and the validity of this numerical model is tested using physical models. The validated mathematical model is then used in conjunction with a computer-controlled tensile testing apparatus to simulate the loading regime placed on algal materials. The resulting information can be used to create a more precise mathematical model.     

Chromosomal polymorphism in two species of Hypancistrus (Siluriformes: Loricariidae): an integrative approach for understanding their biodiversity

Structural chromosome changes are widely described in different vertebrate groups and generate genetic, phenotypic and behavioral diversity. During the evolution of loricariids, several rearrangements (fissions, fusions, inversions) seem to have occurred. Hypancistrus, tribe Ancistrini, are highly demanded for fishkeeping around the world. In this tribe, the diploid chromosome number 2n = 52 is considered a synapomorphy, and paracentric-type inversions appear to be involved in the chromosomal evolution of the tribe. The present study investigated the karyotypes of H. zebra and H. cf. debilittera using cytogenetic, classical and molecular tools, as well as DNA barcoding. Data reveal that, although diploid number in both species corroborates the proposed synapomorphy for the tribe, there is a complex karyotype dynamics, reflected in the intense chromosomal polymorphism, resulting from rearrangements involving ribosomal regions (5S and 18S rDNA), which are suggested to be paracentric inversions. Besides, DNA barcode confirms reciprocal monophyletism between the species, validating the existence of two species, only. This scenario, coupled with genomic instability caused by exogenous sequences such as Rex-3 retrotransposons and the species’ sedentary lifestyle, which helps the fast polymorphism fixation, may reflect different phenotypic color patterns in natural populations, as observed in H. cf. debilittera.     

Deciphering the products of evolution at the species level: the need for an integrative taxonomy

Progress in molecular techniques together with the incorporation of phylogenetic analyses of DNA into taxonomy have caused an increase in the number of species’ discoveries in groups with morphological characters that are difficult to study or in those containing polytypic species. But some emerged criticisms plead for a taxonomic conservatism grounded either on the requirement of providing evidences of morphological distinctiveness or reproductive barriers to erect new species names. In a case study of taxonomic research on Neotropical frogs, we combine several lines of evidence (morphological characters, prezygotic reproductive isolation and phylogenetic analyses of mitochondrial DNA) to test the status of 15 nominal species and to assess the degree of agreement of the different lines of evidence. Our study reveals that morphology alone is not sufficient to uncover all species, as there is no other single line of evidence independently. Full congruence between lines of evidence is restricted to only four out of the 15 species. Five species show congruence of two lines of evidence, whereas the remaining six are supported by only one. The use of divergence in morphological characters seems to be the most conservative approach to delineate species boundaries because it does not allow the identification of some sibling reciprocally monophyletic species differing in their advertisement calls. The separate analysis of differences in advertisement calls (evidence of reproductive isolation) or of phylogenetic data alone also shows limitations, because they do not support some morphological species. Our study shows that only an integrative approach combining all sources of evidence provides the necessary feedback to evaluate the taxonomic status of existing species and to detect putative new ones. Furthermore, the application of integrative taxonomy enables the identification of hypotheses about the existence of species that will probably be rejected or changed, and those that can be expected to persist.     

The systematics of Zoochlorella revisited employing an integrative approach

Symbiosis of green algae with protozoa and invertebrates has been studied for more than 100 years. Endosymbiotic green algae are widely distributed in ciliates (e.g. Paramecium, Stentor, Climacostomum, Coleps, Euplotes), heliozoa (e.g. Acanthocystis) and invertebrates (e.g. Hydra, Spongilla), and have traditionally been identified as named or unnamed species of Chlorella Beij. or Zoochlorella K. Brandt or referred to as Chlorella‐like algae or zoochlorellae. We studied 17 strains of endosymbionts isolated from various hosts and geographical localities using an integrative approach (nuclear encoded small subunit and internal transcribed spacer regions of rRNA gene sequences including their secondary structures, morphology, physiology and virus sensitivity). Phylogenetic analyses have revealed them to be polyphyletic. The strains examined belong to five independent clades within the Trebouxiophyceae (Choricystis‐, Elliptochloris‐, Auxenochlorella‐ and Chlorella‐clades) and Chlorophyceae (Scenedesmus‐clade). The most studied host organism, Paramecium bursaria, harbours endosymbionts representing at least five different species. On the basis of our results, we propose a taxonomic revision of endosymbiotic ‘Chlorella’‐like green algae. Zoochlorella conductrix K. Brandt is transferred to Micractinium Fresen. and Zoochlorella parasitica K. Brandt to Choricystis (Skuja) Fott. It was shown that Choricystis minor (Skuja) Fott, the generitype, is a later heterotypic synonym of Choricystis parasitica (K. Brandt) comb. nov. A new species, Chlorella heliozoae, is proposed to accommodate the endosymbiont of Acanthocystis turfacea.     

Natural product sciences: an integrative approach to the innovations of plant natural products

Science China Life Sciences - The study on plant natural products not only helps us understand that their structural diversity is the inevitable result of plant species diversity, but also helps us...     

Avian malaria on Madagascar: prevalence,biodiversity and specialization of haemosporidian parasites

Previous studies about geographic patterns of species diversity of avian malaria parasites and others in the Order Haemosporida did not include the avian biodiversity hotspot Madagascar. Since there are few data available on avian malaria parasites on Madagascar, we conducted the first known large-scale molecular-based study to investigate their biodiversity. Samples (1067) from 55 bird species were examined by a PCR method amplifying nearly the whole haemosporidian cytochrome b gene (1063?bp). The parasite lineages found were further characterized phylogenetically and the degree of specialization was determined with a newly introduced host diversity index (Hd). Our results demonstrate that Madagascar indeed represents a biodiversity hotspot for avian malaria parasites as we detected 71 genetically distinct parasite lineages of the genera Plasmodium and Haemoproteus. Furthermore, by using a phylogenetic approach and including the sequence divergence we suspect that the detected haemosporidian lineages represent at least 29 groups i.e. proposed species. The here presented Hd values for each parasite regarding host species, genus and family strongly support previous works demonstrating the elastic host ranges of some avian parsites of the Order Haemosporida. Representatives of the avian parasite genera Plasmodium and Leucocytozoon tend to more often be generalists than those of the genus Haemoproteus. However, as demonstrated in various examples, there is a large overlap and single parasite lineages frequently deviate from this rule.     

The biodiversity of arthropods from Australian rainforest canopies: General introduction,methods, sites and ordinal results

Abstract The arthropod assemblages occurring in the canopies of tropical, subtropical and cool temperate sites have been sampled using a pyrethrum knockdown technique. Details of the techniques used and the climate and vegetation of the areas studied are presented together with an analysis of the distribution of individual arthropods across Orders. An approach using generalized linear modelling partitioned the variance in numbers among sites within forest types and across the three forest types. The effects of both these components were significant. The differences between the ordinal signatures of each forest type are discussed and a number of hypotheses proposed to account for these differences, based on knowledge of the biology of the groups concerned. For the tropical and subtropical sites a comparison was made between samples collected in the low to mid-canopy with ones collected in the high canopy. Numbers of both insects and non-insects collected differed significantly with height in the subtropical forest and the distribution of insects across Orders was also significantly different in this forest type. In the tropical forests numbers of insects differed significantly between the two strata but neither the numbers of non-insects nor the ordinal profiles of either insects or non-insects were shown to be significantly different.     

Bridging experiments, models and simulations: an integrative approach to validation in computational cardiac electrophysiology

Computational models in physiology often integrate functional and structural information from a large range of spatiotemporal scales from the ionic to the whole organ level. Their sophistication raises both expectations and skepticism concerning how computational methods can improve our understanding of living organisms and also how they can reduce, replace, and refine animal experiments. A fundamental requirement to fulfill these expectations and achieve the full potential of computational physiology is a clear understanding of what models represent and how they can be validated. The present study aims at informing strategies for validation by elucidating the complex interrelations among experiments, models, and simulations in cardiac electrophysiology. We describe the processes, data, and knowledge involved in the construction of whole ventricular multiscale models of cardiac electrophysiology. Our analysis reveals that models, simulations, and experiments are intertwined, in an assemblage that is a system itself, namely the model-simulation-experiment (MSE) system. We argue that validation is part of the whole MSE system and is contingent upon 1) understanding and coping with sources of biovariability; 2) testing and developing robust techniques and tools as a prerequisite to conducting physiological investigations; 3) defining and adopting standards to facilitate the interoperability of experiments, models, and simulations; 4) and understanding physiological validation as an iterative process that contributes to defining the specific aspects of cardiac electrophysiology the MSE system targets, rather than being only an external test, and that this is driven by advances in experimental and computational methods and the combination of both.     

A new family of soft corals (Anthozoa,Octocorallia, Alcyonacea) from the aphotic tropical eastern Pacific waters revealed by integrative taxonomy

The new family Aquaumbridae is described based on distinct morphological characters and supported by a molecular phylogenetic analysis. Aquaumbridae is similar to Nidaliidae, Nepththeidae and Alcyoniidae in having arborescent colonies and lacking axis structure or stolons, but differs from them in having very different sclerite composition and having conspicuous transparent jelly-like lobes. Phylogenetic analysis of two mitochondrial genes, ND2 and mtMutS, strongly supports its placement in a separated clade. Herein we describe Aquaumbra klapferi sp. nov., gen. nov. in the new family. The organisms were obtained from the seamounts, ridges and canyons out of the insular shelf of Isla del Coco, Costa Rica, down to 400 m depth. The new species represents the first discovery of a soft coral in an eastern Pacific oceanic island, and provides hints of the biodiversity of the largely unexplored deep waters of the tropical eastern Pacific.     

Energy budgets, growth rates, and thermal constraints: toward an integrative approach to the study of life-history variation

Variation in thermal constraints on activity has been hypothesized to be an important ecological source of geographic variation in growth rates of juvenile eastern fence lizards Sceloporus undulatus. However, most of the evidence to support this hypothesis is either inferential or indirect. In this study, I quantitatively compared thermal constraints on activity and their relationship to growth rates of free-ranging juvenile fence lizards from two extremes of the range of variation in growth rate (Nebraska and New Jersey) used in a reciprocal transplant experiment. I also examined energy allocation made to growth and storage by yearling lizards. Reduced growth rates in New Jersey of normally fast-growing hatchlings from Nebraska were associated with a more stringent thermal constraint on activity corresponding to a 2-3-h shorter predicted daily activity period in New Jersey compared to Nebraska. The thermal constraint on activity was particularly strong (24% less time available in New Jersey compared to Nebraska) during the period when hatchling lizards emerge (August-October). An 8% reduction in total activity time available over the course of a single year was associated with a 7% reduction in the total amount of energy accumulated by lizards in New Jersey. Differences in the total amount of energy available for allocation were also accompanied by differences in how energy was allocated. Lizards from New Jersey had an allocatable energy pool of approximately 40.34 kJ (88% to growth, 12% to storage, and 0% to reproduction). Lizards from Nebraska had an allocatable pool of 43.44 kJ (22% to growth, 18% to storage, and 60% to reproduction). This study joins others in advocating and illustrating an integrative approach to determining the causes and consequences of life-history variation by combining experimental, comparative, and phylogenetic methods in a single system.     

Functional demands of dynamic biological adhesion: an integrative approach

Climbing organisms are constantly challenged to make their way rapidly and reliably across varied and often novel terrain. A diversity of morphologically and mechanically disparate attachment strategies have evolved across widely distributed phylogenetic groups to aid legged animals in scaling these surfaces, notable among them some very impressive adhesive pads. Despite the differences between, for example, the dry fibrillar pads of geckos and the smooth, secretion-aided pads of stick insects, I hypothesize that they face similar functional demands in their environment. I outline three broad criteria defining dynamic biological adhesion: reusability, reversibility, and substrate tolerance. Organismal adhesive pads must be able to attach repeatedly without significant decline in performance, detach easily at will, and adhere strongly to the broadest possible range of surfaces in their habitat. A survey of the literature suggests that evidence for these general principles can be found in existing research, but that many gaps remain to be filled. By taking a comparative, integrative approach to biological dynamic adhesion, rather than focusing on a few model organisms, investigators will continue to discover new and interesting attachment strategies in natural systems.     

Beetle assemblages from an Australian tropical rainforest show that the canopy and the ground strata contribute equally to biodiversity

There remains great uncertainty about how much tropical forest canopies contribute to global species richness estimates and the relative specialization of insect species to vertical zones. To investigate these issues, we conducted a four-year sampling program in lowland tropical rainforest in North Queensland, Australia. Beetles were sampled using a trap that combines Malaise and flight interception trap (FIT) functions. Pairs of this trap, one on the ground and a second suspended 15-20 m above in the canopy were located at five sites, spaced 50 m or more apart. These traps produced 29986 beetles of 1473 species and 77 families. There were similar numbers of individuals (canopy 14473; ground 15513) and species (canopy 1158; ground 895) in each stratum, but significantly more rare species in the canopy (canopy 509; ground 283). Seventy two percent of the species (excluding rare species) were found in both strata. Using IndVal, we found 24 and 27% of the abundant species (n>or=20 individuals) to be specialized to the canopy and the ground strata, respectively, and equivalent analyses at the family level showed figures of 30 and 22%, respectively. These results show that the canopy and the ground strata both provide important contributions to rainforest biodiversity.     

Concepts of taxonomy and concepts of biodiversity: the problem of interaction

There is, or there should be, an interaction between concepts of taxonomy and biodiversity. On the one hand, taxonomy develops some general and particular classificatory paradigms, which own diversity is to be taken into account to understand the nature of variety of natural kinds. On the other hand, analysis of the properties of biodiversity may put forward nontrivial problems for taxonomy that cannot be deduced directly from its own statements. From the point view of taxonomy, it is argued that the current concept of biodiversity based entirely on the species concept is deeply rooted in reductionistic view of nature. It is outdated epistemologically and should be replaced by the modern taxonomic concept of the hierarchical phylogenetic pattern. Operationally, the latter presumes a possibility for each species to be assigned a certain "phylogenetic weight", according to its phylogenetic uniqueness. From the point view of biodiversity, it is argued that the global biodiversity is a three component entity, as it includes, in addition to phylogenetic and ecological hierarchies, a biomorphic hierarchy, as well. This calls for taxonomy to elaborate the general principles of classification of biomorphs.