Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 599
Filtrar
1.
Parasitol Res ; 118(12): 3337-3347, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31664517

RESUMO

The Amazon represents one of the most complex biomes in the world; however, the temporal variations in parasite community structure of fishes inhabiting this region remain poorly understood. Therefore, processes generating such variations are still unknown. The present study evaluated the long-term temporal variation of community structure of metazoan parasites of Pimelodus blochii collected in Iaco River, State of Acre (Southwestern Brazilian Amazon). A total of 196 parasites were collected over a 6-year period (2012-2017). Twenty-four different taxa of parasites were found, of which 5 Monogenea, 11 Nematoda, 3 Digenea, 1 Acanthocephala, 1 Cestoda, and 3 Crustacea. The overall species richness ranged from 4 in 2012 to 17 in 2016, in which nematodes (larvae and adults) showed higher numerical dominance, diversity, and species richness. However, the annual species richness was similar between the study years, except in 2016, where it showed a distinctly higher value. The overall parasite diversity was also different in 2012 and 2016, whereas the overall abundance differed in 2013 and 2017. The prevalence and abundance of some infracommunities of parasites varied over time. The temporal changes in the parasite community structure of P. blochii are probably related to variations in host-related features, i.e., body size and shift in diet composition as well as to the occurrence of parasites with distinct life history and biology (mainly monogeneans, digeneans, and nematodes). This is the first evaluation of a long-term temporal variation in the structure of the parasite community in fish from the Amazon.


Assuntos
Acantocéfalos/isolamento & purificação , Peixes-Gato/parasitologia , Cestoides/isolamento & purificação , Doenças dos Peixes/parasitologia , Nematoides/isolamento & purificação , Trematódeos/isolamento & purificação , Acantocéfalos/classificação , Animais , Brasil/epidemiologia , Cestoides/classificação , Crustáceos/classificação , Ecossistema , Larva , Nematoides/classificação , Doenças Parasitárias em Animais/epidemiologia , Rios/parasitologia , Trematódeos/classificação
2.
Mar Pollut Bull ; 140: 403-415, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30803661

RESUMO

Shipping is understood to be a major vector for the introduction and spread of marine non-indigenous species (NIS). However, recreational boating is still unregulated and its influence as vector has not yet been assessed for the Mediterranean Sea, which is the second most popular recreational boating destination worldwide. This is the first large-scale study to examine this by a combined biological (analyzing hull and marina fouling) and social approach (boaters surveys on maintenance habits, travel patterns and awareness), focused on peracarid crustaceans. A surprisingly high number of NIS were found on vessels cruising Mediterranean waters, and species compositions suggest an exchange between marina and vessel assemblages. This means recreational boating presents a risk for NIS spread which should warrant regulation. Results also implied that regionally coordinated management should be supported by effective local-scale-based management in the Mediterranean, which could improve upon with targeted environmental education to solve lack of awareness.


Assuntos
Incrustação Biológica , Crustáceos/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Espécies Introduzidas , Esportes Aquáticos , Animais , Crustáceos/classificação , Região do Mediterrâneo , Mar Mediterrâneo , Recreação , Viagem
3.
Integr Zool ; 14(6): 561-575, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30811879

RESUMO

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post-mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post-mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post-mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.


Assuntos
Exoesqueleto , Crustáceos/classificação , Nautilus , Animais , Crustáceos/fisiologia , Nova Caledônia , Oceano Pacífico
5.
Mitochondrial DNA A DNA Mapp Seq Anal ; 30(1): 118-125, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29671658

RESUMO

Ostracods (Crustacea, Ostracoda) are small bivalved crustaceans, contributing over 200 described species to the marine zooplankton community. They are widely distributed and are relatively abundant components of the mesozooplankton, playing an important role in the transport of organic matter to deep layers. However, identification of ostracods based on micro-morphological characters is extremely difficult and time-consuming. Previous fragmentary taxonomic studies of ostracods in the South China Sea (SCA), were based solely on morphology. Here, by analysing the mitochondrial COI gene, we explore the taxa across the SCA using molecular tools for the first time. Our results show that sequence divergence among species varies within a large range, from 12.93% to 35.82%. Sixteen of the taxonomic units recovered by DNA taxonomy agree well with morphology, but Paraconchoecia oblonga, Conchoecia magna and Halocypris brevirostris split into two clades each, each of which contains cryptic species.


Assuntos
Biodiversidade , Crustáceos/genética , Código de Barras de DNA Taxonômico/métodos , Filogenia , Zooplâncton/genética , Animais , Crustáceos/classificação , Código de Barras de DNA Taxonômico/normas , Complexo IV da Cadeia de Transporte de Elétrons/genética , Zooplâncton/classificação
6.
Mar Pollut Bull ; 137: 104-112, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30503415

RESUMO

The adjacent waters of the Yangtze River Estuary are influenced by heavy anthropogenic activities. The benthic ecological status was assessed using the Shannon-Wiener diversity index, the AZTI Marine Biotic Index (AMBI), and the multivariate AMBI (M-AMBI) based on macrofaunal data collected in this area at 51 sites in June 2013 and June 2014. In total, 321 species of macrofauna were identified. Polychaetes were the most dominant, followed by mollusks and crustaceans. The AMBI results showed that 72.55% of the sites were under slight disturbance with a decreasing disturbance trend from inshore to offshore. M-AMBI showed that most of the sites were under lower disturbance level than those shown by AMBI. The Shannon-Wiener diversity index showed that only two sites, near the Yangtze River Estuary and the Zhoushan Islands, respectively, were under moderate status. Other sites were under good or high status, which is consistent with the M-AMBI results.


Assuntos
Crustáceos/crescimento & desenvolvimento , Moluscos/crescimento & desenvolvimento , Poliquetos/crescimento & desenvolvimento , Rios/química , Animais , Biodiversidade , China , Crustáceos/classificação , Ecossistema , Estuários , Moluscos/classificação , Poliquetos/classificação
7.
Biol Lett ; 14(11)2018 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-30404865

RESUMO

Ostracod crustaceans are diverse and ubiquitous in aqueous environments today but relatively few known species have gills. Ostracods are the most abundant fossil arthropods but examples of soft-part preservation, especially of gills, are exceptionally rare. A new ostracod, Spiricopia aurita (Myodocopa), from the marine Silurian Herefordshire Lagerstätte (430 Mya), UK, preserves appendages, lateral eyes and gills. The respiratory system includes five pairs of gill lamellae with hypobranchial and epibranchial canals that conveyed haemolymph. A heart and associated vessels had likely evolved in ostracods by the Mid-Silurian.


Assuntos
Crustáceos/anatomia & histologia , Fósseis/anatomia & histologia , Animais , Crustáceos/classificação , Inglaterra , Sistema Respiratório/anatomia & histologia
8.
Parasitol Res ; 117(12): 3791-3798, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30221326

RESUMO

The present investigation evaluated the influence of seasonality and locality on the structure of the parasite community of the catfish Pimelodus blochii. A total of 160 fish were collected from two rivers in the State of Acre, western Brazilian Amazon: 80 fish in River Acre and 80 in River Iaco, with 40 in each season (rainy and drought). The overall prevalence was 78.7% and 1461 parasite specimens (adults and larvae) were allocated in 22 taxa: 5 of Monogenea, 10 of Nematoda, 3 of Digenea, 1 of Cestoda and 3 of Crustacea. In drought season, Procamallanus (Spirocamallanus) pimelodus and Demidospermus peruvianus were more prevalent in River Acre and Iaco, respectively. The parasite diversity (Brillouin index) as well as the prevalence and abundance of the monogeneans D. peruvianus, D. striatus, Demidospermus sp. and Ameloblastella sp. were higher in River Acre. The parasite community structure were dissimilar among rivers, and seasonally in River Iaco. These results suggest that environmental traits may overshadow seasonal influences on the parasite community structure, which may be related to the higher anthropization in River Acre. Furthermore, seasonality exerted less influence on the parasite community than expected, probably because the two rivers have different hydrological traits than those of other rivers in the Brazilian Amazon. New host and locality records expanded our knowledge of parasite biodiversity of P. blochii.


Assuntos
Peixes-Gato/parasitologia , Cestoides/isolamento & purificação , Crustáceos/classificação , Nematoides/isolamento & purificação , Rios/parasitologia , Animais , Biodiversidade , Brasil , Secas , Feminino , Larva , Masculino , Estações do Ano
9.
Genes Genomics ; 40(9): 1001-1009, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30155712

RESUMO

The genetic relationships of mantis shrimp Oratosquilla oratoria between the coastal waters of China and Japan were not well studied. To reveal the genetic differentiation and genetic structure among populations, we collected populations of mantis shrimp O. oratoria from the coastal waters of China and Japan to analyze the mtDNA control region variation. A total of 309 individuals of O. oratoria were collected from 13 localities (11 from China and 2 from Japan) and a segment of mitochondrial DNA control region was sequenced. Three hundred nine haplotypes were defined, yielding a very high haplotype diversity and nucleotide diversity. Two lineages of O. oratoria were revealed and displayed strong differences in the geographical distribution. In the coastal waters of China, the geographic distribution of the two lineages was completely separated by the Yangtze River estuary; however, the lineages showed geographic sympatry in two populations from Japan. Based on the lineage distribution, three groups were defined. There was no significant genetic differentiation among the populations within the three groups, indicating high gene flow within each group. Significant and negative values for Tajima D and Fu's Fs tests, and mismatch distributions for two lineages indicated population expansion. The present result confirmed that the freshwater outflow from the Yangtze River formed a physical barrier and affected gene exchange. The different distribution patterns of the two lineages in coastal waters of China and Japan indicated that the larvae of O. oratoria were transferred from China to the coastal waters of Japan with a one-way gene flow.


Assuntos
Crustáceos/classificação , Crustáceos/genética , DNA Mitocondrial/genética , Elementos Reguladores de Transcrição , Animais , China , Água Doce , Variação Genética , Haplótipos , Japão , Filogeografia
10.
Proc Biol Sci ; 285(1885)2018 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-30135168

RESUMO

Understanding the evolution of Tetraconata or Pancrustacea-the clade that includes crustaceans and insects-requires a well-resolved hypothesis regarding the relationships within and among its constituent taxa. Here, we assembled a taxon-rich phylogenomic dataset focusing on crustacean lineages based solely on genomes and new-generation Illumina-generated transcriptomes, including 89 representatives of Tetraconata. This constitutes, to our knowledge, the first phylogenomic study specifically addressing internal relationships of Malacostraca (with 26 species included) and Branchiopoda (36 species). Seven matrices comprising 81-684 orthogroups and 17 690-242 530 amino acid positions were assembled and analysed under five different analytical approaches. To maximize gene occupancy and to improve resolution, taxon-specific matrices were designed for Malacostraca and Branchiopoda. Key tetraconatan taxa (i.e. Oligostraca, Multicrustacea, Branchiopoda, Malacostraca, Thecostraca, Copepoda and Hexapoda) were monophyletic and well supported. Within Branchiopoda, Phyllopoda, Diplostraca, Cladoceromorpha and Cladocera were monophyletic. Within Malacostraca, the clades Eumalacostraca, Decapoda and Reptantia were well supported. Recovery of Caridoida or Peracarida was highly dependent on the analysis for the complete matrix, but it was consistently monophyletic in the malacostracan-specific matrices. From such examples, we demonstrate that taxon-specific matrices and particular evolutionary models and analytical methods, namely CAT-GTR and Dayhoff recoding, outperform other approaches in resolving certain recalcitrant nodes in phylogenomic analyses.


Assuntos
Crustáceos/classificação , Filogenia , Animais , Proteínas de Artrópodes/análise , Crustáceos/genética , Análise de Sequência de RNA
11.
Nature ; 556(7701): 366-369, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29643505

RESUMO

Sexual selection favours traits that confer advantages in the competition for mates. In many cases, such traits are costly to produce and maintain, because the costs help to enforce the honesty of these signals and cues 1 . Some evolutionary models predict that sexual selection also produces costs at the population level, which could limit the ability of populations to adapt to changing conditions and thus increase the risk of extinction2-4. Other models, however, suggest that sexual selection should increase rates of adaptation and enhance the removal of deleterious mutations, thus protecting populations against extinction3, 5, 6. Resolving the conflict between these models is not only important for explaining the history of biodiversity, but also relevant to understanding the mechanisms of the current biodiversity crisis. Previous attempts to test the conflicting predictions produced by these models have been limited to extant species and have thus relied on indirect proxies for species extinction. Here we use the informative fossil record of cytheroid ostracods-small, bivalved crustaceans with sexually dimorphic carapaces-to test how sexual selection relates to actual species extinction. We show that species with more pronounced sexual dimorphism, indicating the highest levels of male investment in reproduction, had estimated extinction rates that were ten times higher than those of the species with the lowest investment. These results indicate that sexual selection can be a substantial risk factor for extinction.


Assuntos
Crustáceos/fisiologia , Extinção Biológica , Fósseis , Preferência de Acasalamento Animal , Seleção Genética , Adaptação Fisiológica , Animais , Tamanho Corporal , Crustáceos/anatomia & histologia , Crustáceos/classificação , Feminino , Masculino , Modelos Biológicos , Reprodução , Fatores de Risco , Caracteres Sexuais
12.
Food Chem Toxicol ; 113: 278-286, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29407475

RESUMO

The ingestion of heavy metals through contaminated seafood can causes significant outcomes on human health. In recent years, consume fishes and shrimps has increased in Iran, and several study about heavy metals content in fishes and shrimps from Persian Gulf were carried out to check their food safety. The aims of these systematic reviews and meta-analysis was to summarize the evidence on the relation of the intakes of Arsenic (As) and lead (Pb) levels, based on the origin and sub-groups of shrimp species consumed, Hence that we can estimate the risk of oral cancer induced by Pb and As in these groups of shrimp from the persian gulf. We carried out a search of all suitable studies published between 1995 and 2017 in Scopus, Science Direct, PubMed and Web of Science databases. Since the heterogeneity among studied was significant, we used the random effect model (REM) to perform meta-analysis of data. Data were obtained from 9 articles (14 studies), with 511 samples, and it was reported that pooled levels of As and Pb in the muscle shrimps were 1.37 (95% CI: 0.66-2.08 mg/kg d.w.) and 0.58 (95% CI: 0.33-0.82 mg/kg d.w.), respectively. This pooled levels in muscle shrimps were higher than safe dose reported on Food and Agriculture Organization/World Health Organization guidelines (FAO/WHO). The rank order of shrimps species based on As was Panulirus homarus > Penaeus semisulcatus and for the Pb levels was Litopenaeus vannamei > Panulirus homarus > Fenneropenaeus indicus > Metapenaeus affinis. The lowest and highest risk levels of oral cancer, divided by consumers age groups, were respectively 45-54 (6.94E-04) and 15-24 (8.42E-04) for the Pb, and 45-54 (2.87E-01) and 15-24 (3.51E-01) for arsenic. Incremental Lifetime Cancer Risk (ILCR) of Pb and As was higher than 10-4 and 10-3, respectively. All groups (age) of consumers are subject to the cancer risk of due to the consumption of shrimps contaminated by Pb and As, therefore, should be started a control plan for the reduction of the heavy metal bioaccumulation levels in shrimps of the Persian Gulf coupled to a capillary food safety communication.


Assuntos
Arsênico/análise , Crustáceos/química , Chumbo/análise , Saúde da População , Adolescente , Adulto , Animais , Carcinógenos/análise , Crustáceos/classificação , Feminino , Humanos , Oceano Índico/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/epidemiologia , Músculos/química , Medição de Risco , Alimentos Marinhos/análise , Especificidade da Espécie , Adulto Jovem
13.
PLoS One ; 13(2): e0192601, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29438407

RESUMO

In this study, the authors first obtained the mitochondrial genome of Somanniathelphusa boyangensis. The results showed that the mitochondrial genome is 17,032bp in length, included 13 protein-coding genes, 2 rRNAs genes, 22 tRNAs genes and 1 putative control region, and it has the characteristics of the metazoan mitochondrial genome A+T bias. All tRNA genes display the typical clover-leaf secondary structure except tRNASer(AGN), which has lost the dihydroxyuridine arm. The GenBank database contains the mitochondrial genomes of representatives of approximately 22 families of Brachyura, comprising 56 species, including 4 species of freshwater crab. The authors established the phylogenetic relationships using the maximum likelihood and Bayesian inference methods. The phylogenetic relationship indicated that the molecular taxonomy of S. boyangensis is consistent with current morphological classification, and Parathelphusidae and Potamidae are derived within the freshwater clade or as part of it. In addition, the authors used the COX1 sequence of Somanniathelphusa in GenBank and the COX1 sequence of S. boyangensis to estimated the divergence time of this genus. The result displayed that the divergence time of Somanniathelphusa qiongshanensis is consistent with the separation of Hainan Island from mainland China in the Beibu Gulf, and the divergence time for Somanniathelphusa taiwanensis and Somanniathelphusa amoyensis is consistent with the separation of Taiwan Province from Mainland China at Fujian Province. These data indicate that geologic events influenced speciation of the genus Somanniathelphusa.


Assuntos
Crustáceos/genética , Genoma Mitocondrial , Filogenia , Animais , Códon , Crustáceos/classificação , RNA Ribossômico/genética
14.
Sci Rep ; 8(1): 1365, 2018 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-29358761

RESUMO

The mid-Cretaceous Burmese amber (~99 Ma, Myanmar), widely known for exquisite preservation of theropods, also yields microfossils, which can provide important contextual information on paleoenvironment and amber formation. We report the first Cretaceous ostracod in amber-the gigantic (12.9 mm) right valve of an exclusively marine group (Myodocopa: Myodocopida) preserved in Burmese amber. Ostracods are usually small (0.5-2 mm), with well-calcified carapaces that provide an excellent fossil record extending to at least the Ordovician (~485 million years ago), but they are rarely encountered in amber. The new specimen effectively doubles the age of the ostracod amber record, offering the first representative of the Myodocopa, a weakly calcified group with a poor fossil record. Its carapace morphology is atypical and likely plesiomorphic. The preserved valve appears to be either a moulted exuvium or a dead and disarticulated specimen, and subsequent resin flows contain forest floor inclusions with terrestrial arthropods, i.e., fragmentary remains of spiders, and insect frass. These features resolve an enigmatic taphonomic pathway, and support a marginal marine setting for resin production.


Assuntos
Crustáceos/anatomia & histologia , Fósseis/anatomia & histologia , Animais , Crustáceos/classificação , Mianmar
15.
Sci Rep ; 7(1): 12431, 2017 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-28963498

RESUMO

In this study we produce a standardised dataset for benthic macrofauna and sediments through integration of data (33,198 samples) from 777 grab surveys. The resulting dataset is used to identify spatial and temporal patterns in faunal distribution around the UK, and the role of sediment composition and other explanatory variables in determining such patterns. We show how insight into natural variability afforded by the dataset can be used to improve the sustainability of activities which affect sediment composition, by identifying conditions which should remain favourable for faunal recolonisation. Other big data applications and uses of the dataset are discussed.


Assuntos
Organismos Aquáticos/fisiologia , Big Data , Monitoramento Ambiental/métodos , Sedimentos Geológicos , Animais , Organismos Aquáticos/classificação , Briozoários/classificação , Briozoários/fisiologia , Crustáceos/classificação , Crustáceos/fisiologia , Conjuntos de Dados como Assunto , Ecossistema , Humanos , Moluscos/classificação , Moluscos/fisiologia , Oceanos e Mares , Poliquetos/classificação , Poliquetos/fisiologia , Reino Unido , Urocordados/classificação , Urocordados/fisiologia
16.
PLoS One ; 12(9): e0184060, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28886062

RESUMO

In food deprivation assays, several different responses have been observed in crustaceans. However, studying energy reserves utilization among more than one species during the same starvation period has not yet been performed, particularly to discern whether the responses are due to intrinsic and/or environmental factors. We hypothesize that decapod species with similar feeding habits have the same strategies in the use of energetic reserves during starvation, even though they inhabit different environments. The aim of this study was to compare the energy reserves mobilization of three decapods species (Cherax quadricarinatus, Palaemon argentinus and Munida gregaria) with similar feeding habits, exposed to similar food deprivation conditions. The crayfish, shrimp and squat-lobster were experimentally kept at continuous feeding or continuous starvation throughout 15 days. Every 3rd day, the midgut gland index (MGI), and the glycogen, lipid and protein contents were measured in the midgut gland (MG) and pleon muscle. Palaemon argentinus mobilized more reserves during starvation, followed by C. quadricarinatus, and the last M. gregaria. The starved shrimps presented low MGI, whereas MG showed a reduction in glycogen (from day 6 to 15), lipid (from day 3 to 15), and protein levels (at day 9 and 15) while in their muscle, lipid reserves decreased at days 3 and 6. In C. quadricarinatus, the most affected parameters in the MG were MGI, glycogen (from day 6 to 15), and lipids (at day 12 and 15). In the MG of M. gregaria only the glycogen was reduced during fasting from 3 to 15 days. Even though the three studied species have similar feeding habitats, we found that their energetic profile utilization is different and it could be explained by the habitat, life span, temperature, organ/tissue, and metabolism of the species. Our results may be useful to understand the several different responses of crustaceans during starvation.


Assuntos
Crustáceos/fisiologia , Metabolismo Energético , Privação de Alimentos , Animais , Astacoidea/fisiologia , Crustáceos/classificação , Meio Ambiente , Glicogênio/metabolismo , Metabolismo dos Lipídeos , Músculos/metabolismo , Filogenia , Inanição
17.
Mol Ecol Resour ; 17(6): e160-e173, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28776934

RESUMO

Molecular markers are powerful tools for studying patterns of relatedness and parentage within populations and for making inferences about social evolution. However, the development of molecular markers for simultaneous study of multiple species presents challenges, particularly when species exhibit genome duplication or polyploidy. We developed microsatellite markers for Synalpheus shrimp, a genus in which species exhibit not only great variation in social organization, but also interspecific variation in genome size and partial genome duplication. From the four primary clades within Synalpheus, we identified microsatellites in the genomes of four species and in the consensus transcriptome of two species. Ultimately, we designed and tested primers for 143 microsatellite markers across 25 species. Although the majority of markers were disomic, many markers were polysomic for certain species. Surprisingly, we found no relationship between genome size and the number of polysomic markers. As expected, markers developed for a given species amplified better for closely related species than for more distant relatives. Finally, the markers developed from the transcriptome were more likely to work successfully and to be disomic than those developed from the genome, suggesting that consensus transcriptomes are likely to be conserved across species. Our findings suggest that the transcriptome, particularly consensus sequences from multiple species, can be a valuable source of molecular markers for taxa with complex, duplicated genomes.


Assuntos
Crustáceos/classificação , Crustáceos/genética , Genoma , Repetições de Microssatélites , Transcriptoma , Animais
18.
Proc Natl Acad Sci U S A ; 114(33): 8829-8834, 2017 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-28760973

RESUMO

About half of the world's animal species are arthropods associated with plants, and the ability to consume plant material has been proposed to be an important trait associated with the spectacular diversification of terrestrial insects. We review the phylogenetic distribution of plant feeding in the Crustacea, the other major group of arthropods that commonly consume plants, to estimate how often plant feeding has arisen and to test whether this dietary transition is associated with higher species numbers in extant clades. We present evidence that at least 31 lineages of marine, freshwater, and terrestrial crustaceans (including 64 families and 185 genera) have independently overcome the challenges of consuming plant material. These plant-feeding clades are, on average, 21-fold more speciose than their sister taxa, indicating that a shift in diet is associated with increased net rates of diversification. In contrast to herbivorous insects, most crustaceans have very broad diets, and the increased richness of taxa that include plants in their diet likely results from access to a novel resource base rather than host-associated divergence.


Assuntos
Crustáceos/classificação , Crustáceos/fisiologia , Herbivoria/fisiologia , Filogenia , Animais
19.
An Acad Bras Cienc ; 89(3): 1443-1463, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28793007

RESUMO

Paleocene ostracods and planktonic foraminifera from the Maria Farinha Formation, Paraíba Basin, are herein presented. Eleven ostracod species were identified in the genera Cytherella Jones, Cytherelloidea Alexander, Eocytheropteron Alexander, Semicytherura Wagner, Paracosta Siddiqui, Buntonia Howe, Soudanella Apostolescu, Leguminocythereis Howe and, probably, Pataviella Liebau. The planktonic foraminifera are represented by the genera Guembelitria Cushman, Parvularugoglobigerina Hofker, Woodringina Loeblich and Tappan, Heterohelix Ehrenberg, Zeauvigerina Finlay, Muricohedbergella Huber and Leckie, and Praemurica Olsson, Hemleben, Berggren and Liu. The ostracods and foraminifera analyzed indicate an inner shelf paleoenvironment for the studied section. Blooms of Guembelitria spp., which indicate either shallow environments or upwelling zones, were also recorded reinforcing previous paleoenvironmental interpretations based on other fossil groups for this basin.


Assuntos
Crustáceos/classificação , Foraminíferos/classificação , Animais , Brasil , Crustáceos/ultraestrutura , Foraminíferos/ultraestrutura , Fósseis/ultraestrutura , Microscopia Eletrônica de Varredura
20.
PLoS One ; 12(7): e0177791, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28678866

RESUMO

Assessing the long-term macroevolutionary consequences of sexual selection has been hampered by the difficulty of studying this process in the fossil record. Cytheroid ostracodes offer an excellent system to explore sexual selection in the fossil record because their readily fossilized carapaces are sexually dimorphic. Specifically, males are relatively more elongate than females in this superfamily. This sexual shape difference is thought to arise so that males carapaces can accommodate their very large copulatory apparatus, which can account for up to one-third of body volume. Here we test this widely held explanation for sexual dimorphism in cytheroid ostracodes by correlating investment in male genitalia, a trait in which sexual selection is seen as the main evolutionary driver, with sexual dimorphism of carapace in the genus Cyprideis. We analyzed specimens collected in the field (C. salebrosa, USA; C. torosa, UK) and from collections of the National Museum of Natural History, Washington, DC (C. mexicana). We digitized valve outlines in lateral view to obtain measures of size (valve area) and shape (elongation, measured as length to height ratio), and obtained several dimensions from two components of the hemipenis: the muscular basal capsule, which functions as a sperm pump, and the section that includes the intromittent organ (terminal extension). In addition to the assessment of this primary sexual trait, we also quantified two dimensions of the male secondary sexual trait-where the transformed right walking leg functions as a clasping organ during mating. We also measured linear dimensions from four limbs as indicators of overall (soft-part) body size, and assessed allometry of the soft anatomy. We observed significant correlations in males between valve size, but not elongation, and distinct structural parts of the hemipenis, even after accounting for their shared correlation with overall body size. We also found weak but significant positive correlation between valve elongation and the degree of sexual dimorphism of the walking leg, but only in C. torosa. The correlation between the hemipenis parts, especially basal capsule size and male valve size dimorphism suggests that sexual selection on sperm size, quantity, and/or efficiency of transfer may drive sexual size dimorphism in these species, although we cannot exclude other aspects of sexual and natural selection.


Assuntos
Crustáceos/fisiologia , Fósseis , Genitália/fisiologia , Caracteres Sexuais , Comportamento Sexual Animal/fisiologia , Animais , Tamanho Corporal , Crustáceos/anatomia & histologia , Crustáceos/classificação , Feminino , Genitália/anatomia & histologia , Masculino , Tamanho do Órgão , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA