Institute Biologia

Rio de Janeiro, Brazil

Institute Biologia

Rio de Janeiro, Brazil
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Cruz-Lopez J.A.,Institute Biologia
Revista Mexicana de Biodiversidad | Year: 2013

Guerrobunus franckei sp. nov. is described, from Guerrero, Mexico. This species is similar to G. vallensis Vázquez and Cokendolpher, 1997 in external troglomorphic characters but differs in the male genitalia. Differences and similarities of this new species with the other 3 known species of the genus are discussed.


Cruz-Lopez J.A.,Institute Biologia | Francke O.F.,Institute Biologia
Journal of Arachnology | Year: 2013

The harvestman genus Philora Goodnight & Goodnight 1954 and the type species P. tuxtlae are redescribed, and Philora quetzalzin new species is described. The genus is newly assigned to the family Stygnopsidae Sørensen 1932 based on external morphology and male genitalia, which are described herein for the first time. The genus is compared with the morphologically similar genera Paramitraceras Pickard-Cambridge 1905, Sbordonia Šilhavý 1977, and Troglostygnopsis Šilhavý 1974 sensu stricto. Philora is unique within the family in having a scutum completum. The presence of a scutum completum in Philora and others laniatoreans is discussed. The male genitalia of the genera Paramitraceras, Philora, Troglostygnopsis and presumably the genus Sbordonia, are very similar and share a morphological pattern described here as the Paramitraceras-pattern. © The American Arachnological Society.


Microvelia picinguaba sp. nov., Microvelia ubatuba sp. nov., Paravelia gabrielae sp. nov. and Rhagovelia pseudotijuca sp. nov. are described. The male of Microvelia ioana is described. Microvelia mimula and Microvelia aemulana are synonymized. Microvelia hinei, M. ioana, Microvelia longipes, Microvelia pulchella, Microvelia venustatis, Oiovelia brasiliensis, Oiovelia cunucunumana, Paravelia basalis, Paravelia itatiayana, Rhagovelia denticulata, Rhagovelia hambletoni, Rhagovelia janeira, Rhagovelia robusta, Rhagovelia tenuipes, Rhagovelia zela and Stridulivelia ayacucho are recorded for the first time from São Paulo State. New locality records are given for Husseyella diffidens, Rhagovelia accedens, Rhagovelia aiuruoca, Rhagovelia henryi, Rhagovelia lucida, Rhagovelia modesta, Rhagovelia occulcata, Rhagovelia trepida and Rhagovelia triangula. © EDP Sciences, 2011.


Costa W.J.E.M.,Federal University of Rio de Janeiro | Lima S.M.Q.,Laboratorio Of Biodiversidade Molecular | Bartolette R.,Institute Biologia
Biological Journal of the Linnean Society | Year: 2010

Kryptolebias marmoratus is an important experimental fish, and is considered to represent the only vertebrate species comprising self-fertilizing hermaphroditic individuals. Subsequent to the discovery of this unusual mode of reproduction, approximately 50 years ago, K. marmoratus has been the focus of a series of studies. However, little is known about the evolution of this rare reproduction mode, and data on the biology of closely related species are still unavailable. The present study aimed to histologically analyse the gonads of three K. marmoratus congeners (i.e. Kryptolebias ocellatus, Kryptolebias caudomarginatus, and Kryptolebias brasiliensis) to check the distribution of features related to hermaphroditism that are useful for forming hypotheses about the origin and evolution of the self-fertilization mode of reproduction through the available phylogenies. The data obtained demonstrate that populations of K. caudomarginatus consist of males and hermaphrodites, which supports the hypothesis that hermaphroditism arose at the base of the clade containing K. caudomarginatus, K. marmoratus, and K. ocellatus as a first step towards a more advanced condition, uniquely shared by both K. marmoratus and K. ocellatus, in which males are rare or absent in natural populations, with the subsequent occurrence of self-fertilization. © 2010 The Linnean Society of London.


Rovito S.M.,University of California at Berkeley | Rovito S.M.,Institute Biologia
Molecular Ecology | Year: 2010

Peripatric speciation and the importance of founder effects have long been controversial, and multilocus sequence data and coalescent methods now allow hypotheses of peripatric speciation to be tested in a rigorous manner. Using a multilocus phylogeographical data set for two species of salamanders (genus Hydromantes) from the Sierra Nevada of California, hypotheses of recent divergence by peripatric speciation and older, allopatric divergence were tested. Phylogeographical analysis revealed two divergent lineages within Hydromantes platycephalus, which were estimated to have diverged in the Pliocene. By contrast, a low-elevation species, Hydromantes brunus, diverged from within the northern lineage of H. platycephalus much more recently (mid-Pleistocene), during a time of major climatic change in the Sierra Nevada. Multilocus species tree estimation and coalescent estimates of divergence time, migration rate, and growth rate reject a scenario of ancient speciation of H. brunus with subsequent gene flow and introgression from H. platycephalus, instead supporting a more recent divergence with population expansion. Although the small, peripheral distribution of H. brunus suggests the possibility of peripatric speciation, the estimated founding population size of the species was too large to have allowed founder effects to be important in its divergence. These results provide evidence for both recent speciation, most likely tied to the climatic changes of the Pleistocene, and older lineage divergence, possibly due to geological events, and add to evidence that Pleistocene glacial cycles were an important driver of diversification in the Sierra Nevada. © 2010 Blackwell Publishing Ltd.


Corte G.N.,Institute Biologia
Invertebrate Reproduction and Development | Year: 2015

The reproductive cycle and parasitism in the clam Anomalocardia brasiliana were studied in two different areas, an intermediate beach (Cidade) and a tidal flat (Araçá), in Southeast Brazil. Four gametogenic stages were described for males and females in both areas. Mature and spawning individuals were present throughout the period of study at Cidade and Araçá; however, major temporal differences were recorded between sites. Whereas only a few individuals in the resting stage were recorded at Cidade throughout the study period, resting stage individuals were frequent at Araçá. Moreover, a shorter period of gametogenesis was observed at Araçá than at Cidade. Oocyte number was the most effective parameter to differentiate gametogenic stages. An unidentified digenetic trematode was the only parasite infecting A. brasiliana at the study sites, and caused castration of all hosts. Parasite prevalence (proportion of infected hosts) was similar and low (ca 7.5%) at Cidade and Araçá and therefore is not expected to compromise the reproductive output of these populations. Comparison with data from previous studies suggests a latitudinal pattern for the reproductive biology of A. brasiliana, with resting stages occurring only at two high-latitude sites; however, no evidence was found for a latitudinal pattern of trematode prevalence in this species. © 2015 © 2015 Taylor & Francis.


A new species of the genus Diplocentrus Peters, 1861 is described, based on several specimens collected in the Mexican state of Oaxaca. It is characterized by a high telotarsal spiniform setae count (4- 5/5:5/6:6/6:6/6-7), and the pectinal tooth counts of 12-15, mode = 13 (male) or 11-13, mode = 12 (female). With the description of this species, the diversity of the genus is increased to 51 species in Mexico. © C.E. Santibáñez-López.


Segovia J.M.G.,Institute Biologia | Segovia J.M.G.,University of Sao Paulo | Del-Claro K.,Institute Biologia | Willemart R.H.,University of Sao Paulo | Willemart R.H.,Federal University of São Paulo
Animal Behaviour | Year: 2015

Prey consumption depends on the predator's ability to locate, capture and handle prey. We investigated these three steps in interactions between the delicate-bodied recluse spider Loxosceles gaucho (Araneae) and a heavy-bodied and armoured harvestman, Mischonyx cuspidatus (Opiliones). Although previous research suggested that the hard integument of such harvestmen protects them from being preyed upon by spiders larger than Loxosceles, indirect evidence suggested that Loxosceles spiders can subdue these prey. In the present study, we tested the following three hypotheses with regard to L.gaucho: (1) spiders use chemical cues left by prey to select foraging sites; (2) vibratory cues of prey are essential information in the predatory process; and (3) the spider's web sheetallows adequate handling of prey so vulnerable body regions of the prey can be bitten. To understand how a delicate predator can overcome the defences of a heavy-bodied and well-defended prey, we also quantitatively described the spider's behaviour. To test hypothesis 1, we compared the time spent in areas with harvestmen, crickets and no cues. For hypothesis 2, we compared latency to bite and number of bites in the presence or absence of vibratory information, and for hypothesis 3, we compared latency to detect prey, latency to capture prey and predation success. All three hypotheses were rejected. Loxosceles gaucho seems to be exceptional among spiders by not needing its web, indirect prey chemical cues, or prey's substrate borne vibrations to hunt the tested prey. What enables L.gaucho to prey upon M.cuspidatus is its unique hunting strategy, compared to previously studied spiders: it touches the prey with its tarsi possibly to locate weak parts of the prey's body, such as joints and distal parts of the legs, then it delivers several bites to these vulnerable areas. Our study is the first to document and describe how recluse spiders overcome the defences of an armoured harvestman. © 2015 The Association for the Study of Animal Behaviour.


Justi S.A.,Institute Biologia | Russo C.A.M.,Institute Biologia | Mallet J.R.D.S.,Instituto Oswaldo Cruz | Obara M.T.,University of Brasilia | Galvao C.,Instituto Oswaldo Cruz
Parasites and Vectors | Year: 2014

Background: The Triatomini and Rhodniini (Hemiptera: Reduviidae) tribes include the most diverse Chagas disease vectors; however, the phylogenetic relationships within the tribes remain obscure. This study provides the most comprehensive phylogeny of Triatomini reported to date. Methods. The relationships between all of the Triatomini genera and representatives of the three Rhodniini species groups were examined in a novel molecular phylogenetic analysis based on the following six molecular markers: the mitochondrial 16S; Cytochrome Oxidase I and II (COI and COII) and Cytochrome B (Cyt B); and the nuclear 18S and 28S. Results: Our results show that the Rhodnius prolixus and R. pictipes groups are more closely related to each other than to the R. pallescens group. For Triatomini, we demonstrate that the large complexes within the paraphyletic Triatoma genus are closely associated with their geographical distribution. Additionally, we observe that the divergence within the spinolai and flavida complex clades are higher than in the other Triatoma complexes. Conclusions: We propose that the spinolai and flavida complexes should be ranked under the genera Mepraia and Nesotriatoma. Finally, we conclude that a thorough morphological investigation of the paraphyletic genera Triatoma and Panstrongylus is required to accurately assign queries to natural genera. © 2014 Justi et al.; licensee BioMed Central Ltd.


Aizza L.C.B.,Institute Biologia | Dornelas M.C.,Institute Biologia
Journal of Nucleic Acids | Year: 2011

Most of the plant pigments ranging from red to purple colors belong to the anthocyanin group of flavonoids. The flowers of plants belonging to the genus Passiflora (passionflowers) show a wide range of floral adaptations to diverse pollinating agents, including variation in the pigmentation of floral parts ranging from white to red and purple colors. Exploring a database of expressed sequence tags obtained from flower buds of two divergent Passiflora species, we obtained assembled sequences potentially corresponding to 15 different genes of the anthocyanin biosynthesis pathway in these species. The obtained sequences code for putative enzymes are involved in the production of flavonoid precursors, as well as those involved in the formation of particular ("decorated") anthocyanin molecules. We also obtained sequences encoding regulatory factors that control the expression of structural genes and regulate the spatial and temporal accumulation of pigments. The identification of some of the putative Passiflora anthocyanin biosynthesis pathway genes provides novel resources for research on secondary metabolism in passionflowers, especially on the elucidation of the processes involved in floral pigmentation, which will allow future studies on the role of pigmentation in pollinator preferences in a molecular level. © 2011 Lilian Cristina Baldon Aizza and Marcelo Carnier Dornelas.

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