Cyanobacteria reduction in the integrated culture of Pacific white shrimp and West India pointed venus in a biofloc system

This study aimed to evaluate the integrated culture of the Pacific white shrimp (Litopenaeus vannamei) and the West Indian pointed venus (Anomalocardia flexuosa) reared in a biofloc system. The performance of both species and the phytoplankton community were evaluated. Shrimp monoculture and three stocking densities of West Indian pointed venus (2.5, 5.0 and 7.5 Kg m-3) were evaluated in 0.05 m3 tanks. First of all, the addition of A. brasiliana did not affect the water quality parameters of the culture. Regarding the phytoplankton community, 13 taxa were found: 5 cyanobacteria, 4 dinoflagellates, 3 diatoms and 1 green algae. Although diatoms were dominant at the beginning of cultivation, in the middle and at the end a cyanobacterial dominance was observed (proven by ANOSIM and nMDS). The taxa that most contributed to the abundance of cyanobacteria were Aphanocapsa sp. and Pseudanabaena sp. Regarding the performance of the shrimp, all integrated treatments present the higher growth performances (final weight, yield and survival) when compared to shrimp monoculture. Moreover, gradual mortalities of A. brasiliana were observed, probably due to the high concentration of cyanobacteria. Thus, it can be observed that the integration of molluscs in shrimp culture can reduce the concentration of harmful algae and improve the zootechnical performance of the shrimp

Alterations in sperm long RNA contribute to the epigenetic inheritance of the effects of postnatal trauma

Abstract: Psychiatric diseases have a strong heritable component known to not be restricted to DNA sequence-based genetic inheritance alone but to also involve epigenetic factors in germ cells. Initial evidence suggested that sperm RNA is causally linked to the transmission of symptoms induced by traumatic experiences. Here, we show that alterations in long RNA in sperm contribute to the inheritance of specific trauma symptoms. Injection of long RNA fraction from sperm of males exposed to postnatal trauma recapitulates the effects on food intake, glucose response to insulin and risk-taking in adulthood whereas the small RNA fraction alters body weight and behavioural despair. Alterations in long RNA are maintained after fertilization, suggesting a direct link between sperm and embryo RNA

Virus effects on plant quality and vector behavior are species specific and do not depend on host physiological phenotype

There is growing evidence that plant viruses manipulate host plants to increase transmission-conducive behaviors by vectors. Reports of this phenomenon frequently include only highly susceptible, domesticated annual plants as hosts, which constrains our ability to determine whether virus effects are a component of an adaptive strategy on the part of the pathogen or simply by-products of pathology. Here, we tested the hypothesis that transmission-conducive effects of a virus (Turnip yellows virus [TuYV]) on host palatability and vector behavior (Myzus persicae) are linked with host plant tolerance and physiological phenotype. Our study system consisted of a cultivated crop, false flax (Camelina sativa) (Brassicales: Brassicaceae), a wild congener (C. microcarpa), and a viable F1 hybrid of these two species. We found that the most tolerant host (C. microcarpa) exhibited the most transmission-conducive changes in phenotype relative to mock-inoculated healthy plants: Aphids preferred to settle and feed on TuYV-infected C. microcarpa and did not experience fitness changes due to infection—both of which will increase viruliferous aphid numbers. In contrast, TuYV induced transmission-limiting phenotypes in the least tolerant host (C. sativa) and to a greater degree in the F1 hybrid, which exhibited intermediate tolerance to infection. Our results provide no evidence that virus effects track with infection tolerance or physiological phenotype. Instead, vector preferences and performance are driven by host-specific changes in carbohydrates under TuYV infection. These results provide evidence that induction of transmission-enhancing phenotypes by plant viruses is not simply a by-product of general pathology, as has been proposed as an explanation for putative instances of parasite manipulation by viruses and many other taxa

A new species of Brachycephalus (Anura: Brachycephalidae) from the northern portion of the state of Rio de Janeiro, southeastern Brazil

Abstract Brachycephalus is a genus of small ground-dwelling anurans, endemic to the Brazilian Atlantic Forest. Recent molecular analyses have corroborated the monophyly of three species groups within this genus (B. ephippium, B. ephippium, and B. ephippium). In the meantime, the genus has been targeted as a group with recent taxonomic issues owing to its interspecific morphological similarity and genetic conservatism. Herein, we describe a new species of Brachycephalus from the northern portion of Serra do Mar mountain range, in the state of Rio de Janeiro, Brazil. It belongs to the B. ephippium species group, exhibiting moderate hyperossification of the skull and vertebral column. The new species can be distinguished from all other congeners based on morphological, acoustic, and molecular data. Furthermore, we provide information on osteology and natural history of the new species

Rapid transcriptional plasticity of duplicated gene clusters enables a clonally reproducing aphid to colonise diverse plant species

Background: The prevailing paradigm of host-parasite evolution is that arms races lead to increasing specialisation via genetic adaptation. Insect herbivores are no exception and the majority have evolved to colonise a small number of closely related host species. Remarkably, the green peach aphid, Myzus persicae, colonises plant species across 40 families and single M. persicae clonal lineages can colonise distantly related plants. This remarkable ability makes M. persicae a highly destructive pest of many important crop species. Results: To investigate the exceptional phenotypic plasticity of M. persicae, we sequenced the M. persicae genome and assessed how one clonal lineage responds to host plant species of different families. We show that genetically identical individuals are able to colonise distantly related host species through the differential regulation of genes belonging to aphid-expanded gene families. Multigene clusters collectively upregulate in single aphids within two days upon host switch. Furthermore, we demonstrate the functional significance of this rapid transcriptional change using RNA interference (RNAi)-mediated knock-down of genes belonging to the cathepsin B gene family. Knock-down of cathepsin B genes reduced aphid fitness, but only on the host that induced upregulation of these genes. Conclusions: Previous research has focused on the role of genetic adaptation of parasites to their hosts. Here we show that the generalist aphid pest M. persicae is able to colonise diverse host plant species in the absence of genetic specialisation. This is achieved through rapid transcriptional plasticity of genes that have duplicated during aphid evolution