Reproduction of the annual fish Austrolebias nigrofasciatus (Rivulidae) maintained at different temperatures

Temperature is considered an important factor that influences the life cycle of annual fishes, however the thermal preferendum of Austrolebias nigrofasciatus reproduction has not been defined. The hypothesis was that the fecundity of the species would respond differently within the temperature range analyzed, presenting an optimum thermal. Thus, this study investigated the effect of temperature on the fecundity of A. nigrofasciatus for the first time under laboratory conditions. Pairs of A. nigrofasciatus were placed in aquaria with temperatures of 17, 21 or 25°C, with four pairs (replicates) for each treatment, for five weeks. Contrary to expected, there were no significant differences in fecundity parameters among the tested temperatures, but the weekly fecundity at 17 and 21°C was more homogeneous than at 25°C. During the experimental period, the temperature did not affect male growth; however, at 25°C there was a negative effect on female body growth. The condition factor was also influenced, suggesting a tendency towards a negative energy balance with increasing temperature. The results indicate that temperatures between 17 and 21°C are suitable for broodstock maintenance.     

Molecular phylogeny of the western South Atlantic Sciaenidae based on mitochondrial and nuclear data

Fragments of mitochondrial (COI and rRNA 16S) and nuclear (Tmo-4C4) genes were sequenced to evaluate the phylogenetic relationships among 15 genera of the western South Atlantic Sciaenidae, two freshwater genera and the northwest Pacific Larimichthys crocea.Our results suggest a great diversification for the western Atlantic assemblage; the monophyly of Macrodon, Menticirrhus and Plagioscion genera; the distinctiveness of Bardiella, Stellifer and Ophioscion as belonging to the same clade; the possible existence of two distinct groups in Stellifer; the closer relationship between Lonchurus and Paralonchurus; the non-monophyly of Cynoscion; and the remarkable diversification of Larimus breviceps populations in the Brazilian coast. This is the most comprehensive study evaluating the phylogenetic relationships of the western Atlantic sciaenid and provides a guide for future studies within this family.     

High-affinity transport,cyanide-resistant respiration,and ethanol production under aerobiosis underlying efficient high glycerol consumption by Wickerhamomyces anomalus

Journal of Industrial Microbiology & Biotechnology - Wickerhamomyces anomalus strain LBCM1105 was originally isolated from the wort of cachaça (the Brazilian fermented sugarcane...     

Contribution of genetic distances studies to the taxonomy ofAteles,particularlyAteles paniscus paniscus andAteles paniscus chamek

We studied 20 electrophoretic loci in two populations ofAteles (Ateles paniscus paniscus andAteles paniscus chamek). We observed intrapopulational variation at the following loci: esterase D, glyoxalase 1, adenosine deaminase (A. p. chamek) and carbonic anhydrase 2 (A. p. paniscus). The two populations share the most frequent alleles at 17 loci, but we noted great differences in glyoxalase 1, adenosine deaminase and phosphoglucomutase 1.A. p. paniscus is monomorphic for theGLO1 ^*1 allele, which has a frequency of 6% inA. p.chamek. They did not share alleles in relation to the ADA and PGM1 loci. We found a CA2 allele, named hereCA2 ^*1, which has not been described previously in other neotropical primates (Sampaio et al., 1991a), inA. p. paniscus. The present results suggest that the geographical isolation represented by the Rio Amazonas has lasted long enough to support this level of divergence. These observations taken together with chromosomal findings, led us to endorse the proposal of two distinct species:Ateles paniscus andAteles chamek.     

“More than meets the eye”: phylogeographic inferences and remarkable cryptic diversity and in endemic catfish Parotocinclus (Loricariidae: Hypoptopomatinae) from neglected and impacted basins in South America

Conservation Genetics - The restricted range, taxonomic uncertainties and the apparent phylopatric behavior of Parotocinclus (dwarf plecos) make this fish group an excellent model to infer...     

Titi monkey biogeography: Parallel Pleistocene spread by Plecturocebus and Cheracebus into a post‐Pebas Western Amazon

Titi monkeys, subfamily Callicebinae, are a diverse, species‐rich group of Neotropical primates with an extensive range across South America. Their distribution in space and time makes them an interesting primate model for addressing questions of Neotropical historical biogeography. Our aim was to reconstruct the biogeographic history of Callicebinae to better understand their diversification patterns and the history of their colonisation of South America since the late Miocene. We reconstructed a time‐calibrated phylogeny of 19 titi species under Bayesian inference using two mitochondrial and 11 nuclear loci. Species were assigned across eight Neotropical areas of endemism, and statistical biogeographic methods implemented in BioGeoBEARS were employed to estimate ancestral areas using 12 biogeographic models. Our results indicate that the most recent common ancestor to extant titi monkeys was widespread from the present‐day Andean foothills in the Colombian Amazon, through the wet and dry savannas of Bolivia and Brazil, to the southern Atlantic forest of eastern Brazil. Genus‐level divergences were characterised by vicariance of ancestral range in the late Miocene. Species‐level diversification in Cheracebus and the Plecturocebus moloch group occurred as they spread across the Amazon in the Pleistocene and were largely characterised by a sequential, long‐distance “island‐hopping” dispersal model of speciation from a narrow area of origin through jump dispersal across rivers. This study comprises the first large‐scale investigation of the evolutionary history of titi monkeys in the context of Amazonian and South American historical biogeography and sheds light on the processes that generated the great diversity found among Callicebinae.     

Helicobacter pullorum Isolated from Fresh Chicken Meat: Antibiotic Resistance and Genomic Traits of an Emerging Foodborne Pathogen

Meat and meat products are important sources of human intestinal infections. We report the isolation of Helicobacter pullorum strains from chicken meat. Bacteria were isolated from 4 of the 17 analyzed fresh chicken meat samples, using a membrane filter method. MIC determination revealed that the four strains showed acquired resistance to ciprofloxacin; one was also resistant to erythromycin, and another one was resistant to tetracycline. Whole-genome sequencing of the four strains and comparative genomics revealed important genetic traits within the H. pullorum species, such as 18 highly polymorphic genes (including a putative new cytotoxin gene), plasmids, prophages, and a complete type VI secretion system (T6SS). The T6SS was found in three out of the four isolates, suggesting that it may play a role in H. pullorum pathogenicity and diversity. This study suggests that the emerging pathogen H. pullorum can be transmitted to humans by chicken meat consumption/contact and constitutes an important contribution toward a better knowledge of the genetic diversity within the H. pullorum species. In addition, some genetic traits found in the four strains provide relevant clues to how this species may promote adaptation and virulence.     

Comparative morphology of the oocyte surface and early development in four characiformes from the São Francisco River,Brazil

Early development from the egg fertilization to complete resorption of the yolk‐sac is a critical period in the life cycle of teleost fish. Knowledge of this process provides essential parameters for aquaculture and identification of spawning sites in the wild. In the present study, a comparative morphological analysis of the oocyte surface as well as early development was performed in four commercially valuable species from the São Francisco River: Brycon orthotaenia, Leporinus obtusidens, Prochilodus argenteus, and Salminus franciscanus. Stripped oocytes, embryo, and yolk‐sac larvae were analyzed by scanning electron microscopy (SEM) and histology. A set of 10 lectins was used for investigation of lectin‐binding pattern in oocytes. In the four species, the outer layer of the zona radiata reacted to most lectins, indicating complex polysaccharides at the oocyte surface while no reactivity was detected in the inner zona radiata and yolk globules. Typical structural arrangements were recognized at the micropylar region by SEM. The four species showed nonadhesive eggs, short embryonic period (18–20 h at 24 ± 1°C), and poorly developed larvae at hatching. At 24 h posthatching (hph), larvae of the four species had neuromasts on the body surface. Rudimentary cement glands for larval attachment were identified on the cephalic region at 24 and 48 hph in B. orthotaenia and S. franciscanus, and following they were in regression. The time for whole yolk resorption varied among species from 48 to 120 hph, occurring earlier in S. franciscanus, followed by B. orthotaenia, P. argenteus, and L. obtusidens. The formation of the digestive tract and the mouth opening indicated initiation of exogenous feeding 24 h before complete resorption of the yolk. Together, our data indicate similarities in the early development among species that may be related to the life cycle strategies and phylogeny. J. Morphol. 276:1258–1272, 2015. © 2015 Wiley Periodicals, Inc.     

Identification, tissue distribution and evaluation of brain neuropeptide Y gene expression in the Brazilian flounder Paralichthys orbignyanus

Neuropeptide Y (NPY) is one of the most potent stimulants of food intake in vertebrates, mammals and fish. However, the present knowledge about feeding behaviour in fish is still limited and based on studies in a few species. The Brazilian flounder Paralichthys orbignyanus is being considered for aquaculture, and it is important to understand the mechanisms regulating feeding in order to improve its performance in captivity. The objectives of this study were to clone NPY cDNA, evaluate the mRNA levels in different tissues of flounder, and also evaluate brain NPY expression to associate food intake with NPY expression levels. A 597 bp NPY cDNA was cloned from Brazilian flounder brain. NPY expression was detected in all the peripheral tissues analysed. No significant differences were observed in brain NPY gene expression over 24 h after food intake at a temperature of 15 ± 3°C. No correlation was observed among plasma glucose, total protein, cholesterol, triglycerides and NPY expression levels during this 24 h period. On the other hand, mRNA levels were increased after two weeks of fasting at elevated temperatures. Our results suggest that NPY mRNA levels in Brazilian flounder are affected by temperature.