Conservation and versatility of a new set of primers for long‐PCR amplification of complete insect mitochondrial genomes based on Haematobia irritans mtDNA sequences

The amplification of complete mitochondrial genomes by long PCR (polymerase chain reaction) has been a major contribution to the large‐scale sequencing of arthropodan mitochondrial genomes. In this work, we designed six conserved long‐PCR primers to successfully recover the entire mitochondrial genome of the horn fly Haematobia irritans (Diptera: Muscidae) in two overlapping fragments. The conservation and versatility of these primers were tested for 17 other species from four major insect orders: Diptera (14), Coleoptera (1), Lepidoptera (1) and Hymenoptera (1). The amplification of complete mitochondrial genomes in orders other than Diptera suggested an even broader application of these primers, especially within the Hexapoda.     

SYSTEMATIC REVISION OF PSEUDOBEACONIA BORDAS, 1944, AND MENDOCINICHTHYS WHITLEY, 1953 (ACTINOPTERYGII: ‘PERLEIDIFORMES’) FROM THE TRIASSIC OF ARGENTINA

Abstract: The ‘perleidiform’Mendocinichthys and Pseudobeaconia from the Potrerillos and Santa Clara Abajo formations (Upper Triassic; Argentina) are reviewed. Mendocinichthys has been known from a review of this species that is not based on the type material, but on referred specimens in the American Museum of Natural History. However, those specimens are found here to represent a new species of Pseudobeaconia, P. celestae sp. nov. Consequently, Mendocinichthys is restricted here to the type material and, within it, to the only specimen that clearly represents a distinct taxon and is thus designated lectotype. We further performed a cladistic analysis and propose a new family, Pseudobeaconiidae for these two South American Triassic genera, which is mainly characterized by the presence of an incomplete dorsal ridge of spine‐like scales between the skull and the dorsal fin, and scales with straight posterior border, an elevated central region and marginal concentric ridges of ganoine. The cladistic analysis further indicates the existence of some lineages endemic to certain areas of Gondwana and Europe. Pseudobeaconia celestae sp. nov. represents the first record of Pseudobeaconia in the Cacheuta sub‐basin of the Cuyana Basin. The genus was previously known from the Santa Clara sub‐basin of the Cuyana Basin only, and the new record confirms the previous hypothesis of correlation between the sedimentary infilling of these sub‐basins.     

Haematozoa infections in a Great Tit Parus major population in Central Portugal: relationships with breeding effort and health

Blood parasites may act as modulators of their hosts' ecology, life histories and fitness. We studied the prevalence of Plasmodium sp., Haemoproteus sp. and Leucocytozoon sp. and their effects on morphological, biochemical and haematological variables and on breeding effort of Great Tits Parus major . Total prevalence (percentage of individuals infected by any parasite) ranged from 7.7% to 61.1%. There was an overall positive association in prevalence between the three haematozoan parasites. No effect of sex or age on infection status was observed. Negative impacts of infection on physiological condition depended largely on year and/or season and included effects on body condition index, plasma protein and haemoglobin index. There were also indications that parasite infection increased immune response and stress levels and activated antioxidant defence mechanisms. Males with higher fledging success had a higher probability of Haemoproteus infection, and females laying heavier eggs had a higher probability of Plasmodium infection. However, clutch size was negatively associated with the probability of infection by Leucocytozoon and Haemoproteus . Surprisingly, males raising second broods had a lower prevalence of both Haemoproteus and Leucocytozoon . Only 5.7% of first-brood nestlings were infected, but those in infected nestboxes had a lower heterophil/lymphocyte ratio. This study confirms the pathogenicity of blood parasites to the host by demonstrating negative effects of infection on both physiology and breeding performance.     

High European sauropod dinosaur diversity during Jurassic–Cretaceous transition in Riodeva (Teruel, Spain)

Abstract:  Up to now, more than 40 dinosaur sites have been found in the latest Jurassic – earliest Cretaceous sedimentary outcrops (Villar del Arzobispo Formation) of Riodeva (Iberian Range, Spain). Those already excavated, as well as other findings, provide a large and diverse number of sauropod remains, suggesting a great diversity for this group in the Iberian Peninsula during this time. Vertebrae and ischial remains from Riodevan site RD-13 are assigned to Turiasaurus riodevensis (a species described in RD-10, Barrihonda site), which is part of the Turiasauria clade. This is the first time that a taxon is attributed to Turiasaurus genus out of its type site. A Neosauropod caudal vertebra from the RD-11 site has been classified as Diplodocinae indet., supporting the previous attribution on an ilion also found in Riodeva (CPT-1074) referring to the Diplodocidae clade. New remains from the RD-28, RD-41 and RD-43 sites, of the same age, among which there are caudal vertebrae, are assigned to Macronaria. New sauropod footprints from the Villar del Arzobispo Formation complete the extraordinary sauropod record coming to light in the area. The inclusion of other sauropods from different contemporaneous exposures in Teruel within the Turiasauria clade adds new evidence of a great diversity of sauropods in Iberia during the Jurassic–Cretaceous transition. Turiasauria distribution contributes to the understanding of European and global palaeobiogeography.     

Soil conservation in Polylepis mountain forests of Central Argentina: Is livestock reducing our natural capital?

Mountain forests and their soils provide ecological services such as maintenance of biodiversity, provision of clean water, carbon capture and forage for livestock rearing, which is one of the principal economic activities in mountain areas. However, surprisingly little is known about livestock impact in South American mountain forest soils. With the aim of understanding how livestock and topography influence patterns of forest cover, soil compaction, soil loss and soil chemical properties, we analysed these parameters in 100 Polylepis australis woodland plots situated in the humid subtropical mountains of Central Argentina. We used distance from the nearest ranch as an objective index of historical livestock impact and measured standard topographic variables. Our main results reveal that distance from ranch in all cases partly explains tree canopy cover, soil loss, soil compaction and soil chemical properties; suggesting a strong negative effect of livestock. Intermediate altitudes had more tree canopy cover, while landscape roughness – a measure of the variability in slope inclination and aspect – was negatively associated to soil impedance and acidity, and positively associated to soil organic matter content. Finally, flatter areas were more acid. We conclude that livestock has had a substantial influence on forest soil degradation in the Mountains of Central Argentina and possibly other similar South American mountains. Soil degradation should be incorporated into decision making when considering long‐term forest sustainability, or when taking into account retaining livestock for biodiversity conservation reasons. Where soil loss and degradation are ongoing, we recommend drastic reductions in livestock density.     

Chromosome numbers in Brazilian species of Crotalaria (Leguminosae, Papilionoideae) and their taxonomic significance

Chromosome numbers were counted for 23 species of Crotalaria native to Brazil. Among these data there were new counts for 15 taxa, and some confirmed previous reports or represented numbers that were different from those cited previously. The chromosome numbers most frequently found were 2 n  = 16 and 2 n  = 32. Only C. incana L. had 2 n  = 14 and C. tweediana Benth. had 2 n  = 54. The counts 2 n  = 32 and 54 were found in species of section Calycinae and 2 n  = 16 and 14 in species of section Chrysocalycinae . The data revealed the importance of chromosomal parameters in the characterization of sections Calycinae and Chrysocalycinae in Brazil. We discuss the systematic significance and evolutionary aspects for the genus, comparing the results with the two sections that are native in Brazil.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 271–277.     

Ontogenetic variation in density‐dependent growth of brown trout through habitat competition

1. Density‐dependent growth has been widely reported in freshwater fishes, but the ontogenetic evolution of competition and its subsequent effects on growth through a life span remains unclear. 2. Patterns of competition can be described by integrating population abundance data with habitat‐modelling results. Weighted usable area (WUA; m² WUA ha^?1) curves are obtained for each flow value and are then coupled with demographic data to obtain the occupancy rates (trout m^?2 WUA, the density of a given age class related to its suitable habitat) of the WUA for every age class, year and site. 3. We examined a long‐term data series searching for temporal variation in the influence of habitat occupancy rate on the growth of brown trout Salmo trutta. We tested whether (i) mean cohort mass (mean mass of the cohort during the first 3 years of life) is affected by the occupancy rate experienced across a life span; and (ii) the occupancy rate experienced at different ages influenced mean body size. 4. We observed a consistent negative power relationship between average cohort mass and mean occupancy rate through a life span, indicating that stronger cohorts were related to a reduced growth, with likely consequences for individual fitness. 5. The effects of occupancy rate on size‐at‐age were mainly detected in the size attained at the second year of life, but they were because of the competition at different times. Thus, the level of competition varied through ontogeny, in some of the rivers affecting growth since the first year of life, whereas in most of the rivers the main effects on body size resulted from the competition during the second year of life. 6. Occupancy rate appears more appropriate than density for assessing the occurrence of habitat competition in freshwater fishes, since it encompasses the differences in quantity and quality of suitable habitat for each age class. 7. Our study highlights the importance of density‐dependent growth as a key process in the dynamics of brown trout populations, its temporal variation depending on the temporal changes of density and the variation of competition associated with the habitat capacity for each life stage.     

Brood parasitism is associated with increased bacterial contamination of host eggs: bacterial loads of host and parasitic eggs

Factors related to bacterial environment of nests are of primary interest for understanding the causes of embryo infection and the evolution of antimicrobial defensive traits in birds. Nest visitors such as parasites could act as vectors for bacteria and/or affect the hygienic conditions of nests and hence influence the nest bacterial environment. In the present study, we explored some predictions of this hypothetical scenario in the great spotted cuckoo (Clamator glandarius)–magpie (Pica pica) system of brood parasitism. Great spotted cuckoos visit the nests of their magpie hosts and frequently damage some of the host eggs when laying eggs or on subsequent visits. Therefore, it represents a good system for testing the effect of nest visitors on the bacterial environment of nests. In accordance with this hypothesis, we found that the bacterial load of magpie eggshells was greater in parasitized nests, which may suggest that brood parasitism increases the probability of bacterial infection of magpie eggs. Moreover, comparisons of bacterial loads of cuckoo and magpie eggs revealed that: (1) cuckoo eggshells harboured lower bacterial densities than those of their magpie hosts in the same nests and (2) the prevalence of bacteria inside unhatched eggs was higher for magpies than for great spotted cuckoos. These interspecific differences were predicted because brood parasitic eggs (but not host eggs) always experience the bacterial environments of parasitized nests. Therefore, the results obtained in the present study suggest that parasitic eggs are better adapted to environments with a high risk of bacterial contamination than those of their magpie hosts. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 836–848.     

Differential proteomics of dehydration and rehydration in bryophytes: evidence towards a common desiccation tolerance mechanism

All bryophytes evolved desiccation tolerance (DT) mechanisms during the invasion of terrestrial habitats by early land plants. Are these DT mechanisms still present in bryophytes that colonize aquatic habitats? The aquatic bryophyte Fontinalis antipyretica Hedw. was subjected to two drying regimes and alterations in protein profiles and sucrose accumulation during dehydration and rehydration were investigated. Results show that during fast dehydration, there is very little variation in protein profiles, and upon rehydration proteins are leaked. On the other hand, slow dehydration induces changes in both dehydration and rehydration protein profiles, being similar to the protein profiles displayed by the terrestrial bryophytes Physcomitrella patens (Hedw.) Bruch and Schimp. and, to what is comparable with Syntrichia ruralis (Hedw.) F. Weber and D. Mohr. During dehydration there was a reduction in proteins associated with photosynthesis and the cytoskeleton, and an associated accumulation of proteins involved in sugar metabolism and plant defence mechanisms. Upon rehydration, protein accumulation patterns return to control values for both photosynthesis and cytoskeleton whereas proteins associated with sugar metabolism and defence proteins remain high. The current results suggest that bryophytes from different ecological adaptations may share common DT mechanisms.     

Production and morphology of fruit and seeds in Genisteae (Fabaceae) of south-west Spain

The productivity and morphology of fruit and seeds were studied in 30 species (and subspecies) of the tribe Genisteae (Fabaceae) in south-west Spain. The morphological characters of greatest taxonomic value both for the segregation of the two subtribes (Genistinae and Lupininae) recognized in Genisteae and for the delimitation of the lower taxonomic levels (genus and species) are the size of the pod and characters of the pericarp, the colour and weight of the seeds, whether or not an ad exists, and the shape, size, and position of the hilum. In contrast, characters of little taxonomic interest are pod colour, shape and number of seeds, and characters of the lens. There were also found to be major relationships between fruit and seed, and between these and other floral (e.g. corolla size) or reproductive (e.g. polledovule [P/O] and seed/ovule [S/O] ratios) attributes. Thus in this tribe, pod size was positively correlated with corolla size, seed size, the number of viable seeddfruit, and the S/O and P/O ratios. Corolla size was positively correlated with the number of viable seeds/ fruit and with the seed weight. Similarly, the number of seeddfruit was positively correlated with the fruit's weight and with the number of ovules/ovary. Also, the weight of the seeds was positively correlated with the pollen/ovule ratio. There was also positive correlation between the S/O and P/O ratios.