Quality of shells occupied by the hermit crabPagurus geminus: How many hermit crabs are satisfied with their shells?

The rate of changing shells in the hermit crabPagurus geminus was investigated to determine how many hermit crabs are satisfied with their shells. Animal collected from the coast of Oya, Tanabe, Wakayama Prefecture, were presented with fresh gastropod shells newly made by removing the soft parts. Approximately 80% of the hermit crabs changed from their original shells acquired in the natural habitat into fresh shells experimentally given to them and, thus, were regarded as dissatisfied with the shells possessed in the natural habitat. This condition was thought to lead to the fact that hermit crabs occasionally attempted to exchange shells between 2 individuals and even to attack living snails in the natural habitat.     

Increased Wounding of Southern Right Whale (Eubalaena australis) Calves by Kelp Gulls (Larus dominicanus) at Península Valdés,Argentina

At least 626 southern right whale (Eubalaena australis) calves died at the Península Valdés calving ground, Argentina, between 2003 and 2014. Intense gull harassment may have contributed to these deaths. In the 1970s, Kelp Gulls (Larus dominicanus) began feeding on skin and blubber pecked from the backs of living right whales at Valdés. The frequency of gull attacks has increased dramatically over the last three decades and mother-calf pairs are the primary targets. Pairs attacked by gulls spend less time nursing, resting and playing than pairs not under attack. In successive attacks, gulls open new lesions on the whales’ backs or enlarge preexisting ones. Increased wounding could potentially lead to dehydration, impaired thermoregulation, and energy loss to wound healing. The presence, number and total area of gull-inflicted lesions were assessed using aerial survey photographs of living mother-calf pairs in 1974–2011 (n = 2680) and stranding photographs of dead calves (n = 192) in 2003–2011. The percentage of living mothers and calves with gull lesions increased from an average of 2% in the 1970s to 99% in the 2000s. In the 1980s and 1990s, mothers and calves had roughly equal numbers of lesions (one to five), but by the 2000s, calves had more lesions (nine or more) covering a greater area of their backs compared to their mothers. Living mother-calf pairs and dead calves in Golfo Nuevo had more lesions than those in Golfo San José in the 2000s. The number and area of lesions increased with calf age during the calving season. Intensified Kelp Gull harassment at Península Valdés could be compromising calf health and thereby contributing to the high average rate of calf mortality observed in recent years, but it cannot explain the large year-to-year variance in calf deaths since 2000.     

Does a favourable change in the living conditions of young Kenyans affect their body (morphological) structure?

The aim of this study is to describe changes in the body structure of young Kenyans as a result of an upturn in the living conditions. The analyzed changes in their body build were caused by regular lifestyle and nutrition. The research material was male youth aged between 18 and 26. All those young men were students of a basic vocational school in Nairobi (Kenya). The first research was carried out in 1999 (n=121), the second one (n=302) exactly 12 months later and at the same institution. Changes in the body structure were studied on 31 individuals, who were examined twice. The examined parameters included: body height, body weight, chest circumference, waist circumference and thigh circumference. Information was also collected on the period a given student had stayed at that institution, his tribal membership, the number of children in his household and his number in the sequence of births in his family. Also the date of birth (at least the year) was of significance. All the examined men, whose body structure changes were analyzed, belonged to the Bantu language group. The studied individuals were at an age when growth had already finished. A more significant increase was observed in body weight, waist and thigh circumference. A regular schedule of activities and meals served in the dormitory resulted in body weight changes in 87% of those individuals, who were reexamined. As the basic reason for the observed changes one can regard the improvement in the level of nutrition, which was described by the examined individuals as "good".     

Evidence of silver eels contamination by microcystin‐LR at the onset of their seaward migration: what consequences for breeding potential?

Thirty migrating silver eels Anguilla anguilla were collected in a river system where algal blooms occurred yearly. Fifty per cent of eel livers were contaminated by microcystin-LR (mean ± s . d . toxin level: 28·1 ± 22·4 ng g⁻¹). Contaminated silver ( v. healthy) eels had lower fish condition. Consequences of this impact for the breeding potential of these migrating eels are discussed.     

Begomoviruses: what is the secret(s) of their success?

Begomoviruses constitute an extremely successful group of emerging plant viruses transmitted by whiteflies of the Bemisia tabaci complex. Hosts include important vegetable, root, and fiber crops grown in the tropics and subtropics. Factors contributing to the ever-increasing diversity and success of begomoviruses include their predisposition to recombine their genomes, interaction with DNA satellites recruited throughout their evolution, presence of wild plants as a virus reservoir and a source of speciation, and extreme polyphagia and continuous movement of the insect vectors to temperate regions. These features as well as some controversial issues (replication in the insect vector, putative seed transmission, transmission by insects other than B. tabaci, and expansion of the host range to monocotyledonous plants) will be analyzed in this review.     

Play in a captive breeding colony of harbour seals (Phoca vitulina): constrained by time or by energy?

The play of a breeding colony of captive harbour seals ( Phoca vitulina) was documented over a four-year period to identify changes associated with seasonal variations in energy use, and to corroborate previous field studies which were restricted to observations at the hauling grounds during breeding and moulting. Outside the breeding/moulting period, play was more frequent and in some animals average daily food intake was higher. Thyroid hormones did not vary seasonally in any clear manner. The adults increased their daily activity markedly during the breeding/moulting period. It is argued that these changes in play rate were a reflection of constraints on time rather than energy, since the animals played most when mass and fat were being accumulated for the winter. Field observations were confirmed in the laboratory, showing most play to be solitary, with significant amounts of adult play which was more stereotyped than that of younger seals. Behaviour in captivity was less ebullient and sometimes truncated in comparison to that seen in the wild; however, nine new types of play and a more elaborate repertoire of object play were seen in the laboratory, where seals could be observed throughout the year and underwater.     

Does the environmental background (intensive v. outdoor systems) influence the behaviour of piglets at weaning?

Under intensive pig husbandry, outdoor systems offer a more complex physical and social environment compared with indoor systems (farrowing sheds). As the rearing environment affects behavioural development, it can, therefore, influence behavioural responses of pigs to stressful environments in later stages of production. We tested how the rearing environment influenced behavioural responses to a novel arena test in piglets on the day that they were weaned and mixed into large groups. We recorded video footage and compared the behavioural responses of 30 outdoor-raised and 30 farrowing shed-raised piglets tested in an experimental arena and sequentially exposed to four challenges (each for 5 min) on the day of weaning. Quantitative and qualitative behavioural measures were recorded using time budgets and scoring demeanour or ‘qualitative behavioural expression’ (using Qualitative Behavioural Assessment (QBA)). When held in isolation (challenge 1), both groups were scored as more ‘scared/worried’, while outdoor-raised piglets spent more time eating and jumping against the arena walls. Both groups interacted with a plastic ball (challenge 2: exposure to a novel object) during which they were scored as more ‘playful/curious’ than other challenges. When a food bowl was introduced (challenge 3), farrowing shed-raised piglets were more interested in playing with the food bowl itself, whereas outdoor-raised piglets spent more time eating the feed. Finally, there were no significant differences in social behaviour (challenge 4: introduction of another piglet) between the two groups in terms of the latency to contact each other, amount of time recorded engaged in aggressive/non-aggressive social interactions or QBA scores. Although piglets spent 30% of their time interacting with the other piglet, and half of this time (47%) was engaged in negative interactions (pushing, biting), the levels of aggression were not different between the two groups. Overall, outdoor-raised piglets ate more and were scored as more ‘calm/passive’, whereas farrowing shed-raised piglets spent more time investigating their environment and were scored as more ‘playful/inquisitive’. In conclusion, we did not find differences in behaviour between outdoor-raised and farrowing shed-raised piglets that would highlight welfare issues. The differences found in this study may reflect conflicting affective states, with responses to confinement, neophobia and motivation for exploration evident.     

The care of young Pi?on Jays (Gymnorhinus cyanocephalus) and their integration into the flock

Summary Piñon Jays live year round in a social flock that may number from 50 to 300 birds. Young birds form into creches immediately after leaving the nest. Begging calls are important in the formation of creches. In these creches young interact with each other and with their parents. This study was designed to 1. gain an understanding of the parent-young relationships, 2. investigate the operation of the creche, 3. determine the relationship of young jays to other cohorts in the flock.Young birds begged and were sometimes fed by foster parents in addition to their own parents. Parent-young recognition, however, is shown to be a strong component of the social system. Young removed from the nest at 20 days of age and transported 1.9 km from the nest-site were recognized by their parents 21 hr after removal. Another brood of young learned to beg from these parents, and were eventually fed by them. In a wire enclosure in a field situation foster feeding was also observed. In both cases, males were more prone to feed foster young than females.Nestlings at 14 days of age are incapable of giving loud begging calls. These young apparently recognize their parents. Parents appear not to recognize young of this age when they are removed from the nest. Location of the nest is sufficient information for locating nestlings, but young, by recognizing their parents' calls can be prepared to receive food rapidly. This may be an important anti-predator devise as food is transferred rapidly and efficiently.Fledged young concealed in paper bags were recognized by their parents, thus proving that vocalizations are an important component of parent-young recognition and may serve to reduce confusion in the creche by enhancing contact between parent and young.Social interactions of young birds among themselves and also with other cohorts were systematically recorded at a feeding station. During the summer when creches roamed as units, young birds engaged in a relatively large number of aggressive interactions among themselves and few interactions with other cohorts. No older cohort consistently dominated the young. In fall and early winter when the entire flock had reformed the aggressiveness of the young birds declined dramatically. All cohorts engaged the young less than expected and only adult males clearly dominated them. During courtship and nesting the yearlings acted aggressively at about the same frequency as older females but less than older males. Most cohorts still engaged yearlings less than expected.Throughout their first year, young birds appear to enjoy a special status in the flock and are deferred to by most older birds. Young birds did not act like subordinate birds in terms of their approach to the feeder or in their temporal pattern of feeding. Evidence suggests that parent-young recognition may remain in affect for longer than one year.The feeding of young from other nests may occur as a means to keep the creche relatively quiet so as not to attract predators or it may result because males occasionally are successful in stealing copulations from females other than their mates. Under these circumstances kin-selection arguments cannot be applied independent of individual selection. Apparent altruistic acts appear to have a low cost to benefit ratio.Colonial nesting and the creching of young probably first evolved among non-related individuals. These acts allow members to forage as a flock, mutually defend nests, and divide up the labor of protection of the young. Inclusive fitness will be further enhanced if these acts benefit relatives, thus a premium should be placed on recruiting kin into the group but not to the total exclusion of strangers.

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Pflege und Gruppenintegration der Jungen beim Nacktschnabelhäher(Gymnorhinus cyanocephalus)

Zusammenfassung Nacktschnabelhäher leben ganzjährig in Gruppen von 50–300 Individuen. Jungvögel schließen sich unmittelbar nach dem Ausfliegen zu Krippen zusammen, für deren Zustandekommen die Bettelrufe eine große Rolle spielen. Innerhalb der Krippen kommt es zu sozialen Kontakten zwischen den Jungvögeln untereinander und zwischen Jungen und Eltern. Die vorliegende Arbeit hatte drei Ziele und sollte zum Verständnis der Eltern-Jungen-Beziehungen beitragen, die Lebensweise der Krippen klären und schließlich die Beziehungen junger Häher zu anderen Untergruppen innerhalb des Schwarmes untersuchen. (Mit der Bezeichnung Untergruppen werden hier die Zusammenschlüsse von Tieren gleichen Alters und gleichen Geschlechts innerhalb der Gesamtgruppe verstanden, z. B. alle einjährigen usw.)Jungvögel betteln außer ihren eigenen Eltern auch andere Altvögel an und werden manchmal von ihnen gefüttert. Trotzdem ist das persönliche Erkennen von Eltern und Jungen ein wichtiger Faktor im Sozialsystem dieser Art. Das geht aus Versuchen hervor, in denen Jungvögel im Alter von 20 Tagen aus dem Nest genommen und über eine Entfernung von 1.9 km verfrachtet wurden. Sie wurden von ihren Eltern dort 21 Stunden später wiedererkannt. Die Jungen einer anderen Brut lernten diese Eltern ebenfalls anzubetteln und wurden schließlich von ihnen gefüttert. Entsprechende Fütterungen durch fremde Altvögel wurden auch an Jungvögeln beobachtet, die in einer Drahtvoliere im Aufenthaltsgebiet der Krippe gehalten wurden. In beiden Fällen hatten männliche Altvögel einen größeren Anteil an diesen Fütterungen als Weibchen.Vierzehntägige Nestlinge verfügen noch nicht über laute Bettelrufe. Sie sind jedoch offenbar bereits in der Lage, ihre Eltern am Ruf zu erkennen. Umgekehrt richten sich die Eltern um diese Zeit offenbar noch ausschließlich nach dem Standort des Nestes, da sie aus dem Nest genommene Junge nicht als ihre eigenen erkennen. Das frühe Erkennungsvermögen der Jungen für ihre Eltern ist als Feindanpassung anzusehen: Die Jungen sind durch das Hören der elterlichen Rufe auf die bevorstehende Fütterung vorbereitet, und die Futterübergabe selbst kann daher sehr rasch und wirksam erfolgen.Nach dem Ausfliegen erkennen — wie Versuche mit in Papiertüten verborgenen Jungvögeln zeigten — auch die Eltern ihre Jungen an der Stimme. Dadurch wird ein gegenseitiger Kontakt innerhalb der Krippe gewährleistet.An einer Futterstelle wurden die sozialen Verhaltensweisen zwischen den Jungvögeln und zwischen diesen und den Mitgliedern anderer Untergruppen beobachtet und quantitativ erfaßt. Während der Sommermonate, wenn die Krippen als soziale Einheiten umherziehen, kommt es zu einer großen Anzahl aggressiver Auseinandersetzungen zwischen den Jungen, während deren Zahl gegenüber anderen Untergruppen gering war. Es gab keine Untergruppe, die der Jungengruppe ständig überlegen war. Im Herbst und Winter, als die gesamte Gruppe wieder geschlossen auftrat, kam es zu einem drastischen Absinken der Aggressivität der Jungvögel. Die übrigen Untergruppen ließen sich mit den Jungen weit weniger ein als erwartet, und nur alte Männchen waren ihnen klar überlegen. Während der Balz- und Brutzeit entsprach dann die Aggressivität der Jungvögel des Vorjahres etwa der der adulten Weibchen, war aber noch geringer als die der Männchen. Die meisten Untergruppen hatten mit den Jungen um diese Zeit immer noch weniger soziale Interaktionen als zu erwarten war.Während ihres ersten Lebensjahres scheinen die Jungvögel innerhalb der Gruppe eine eigene soziale Stellung innezuhaben und werden von den meisten Altvögeln respektiert. Jungvögel verhielten sich daher bei der Annäherung an die Futterstelle und bei der Futteraufnahme auch durchaus nicht wie rangtiefe Altvögel. Aus den Beobachtungen geht hervor, daß das persönliche Erkennen zwischen Eltern und Jungvögeln für länger als ein Jahr anhält. Für die erwähnte Fütterung fremder Jungvögel werden zwei mögliche Gründe diskutiert: Sie kann dazu beitragen, die gesamte Krippe relativ ruhig zu halten und das Anlocken von Raubfeinden zu vermeiden; oder sie kann darauf beruhen, daß Männchen gelegentlich auch mit fremden Weibchen erfolgreich kopulieren. In diesem Fall können individuelle und Verwandtschaftsselektion nicht scharf voneinander getrennt werden. Dadurch haben diese scheinbar altruistischen Verhaltensweisen eine niedrige Kosten-Nutzen-Relation. Hinzu kommt, daß sie wahrscheinlich reziprok auftreten.Die biologische Bedeutung der Sozialstruktur des Nacktschnabelhähers wird diskutiert: Koloniebrüten und Krippenbildungen von Jungvögeln haben sich zunächst wahrscheinlich bei nicht näher miteinander verwandten Individuen entwickelt. Ein solcher Zusammenschluß bietet mehrere Vorteile: Die Tiere können als Gruppe der Nahrungssuche nachgehen, ihre Nester gemeinsam verteidigen und in bezug auf den Schutz der Jungen eine Art Arbeitsteilung entwickeln.Ihre Gesamteignung (inclusive fitness) kann noch weiter erhöht werden, wenn ein solcher Zusammenschluß sich auf miteinander verwandte Tiere bezieht. Den höchsten Selektionsvorteil besitzen daher wahrscheinlich solche Gruppen, die bevorzugt verwandte Individuen aufnehmen, jedoch fremde nicht völlig ausschließen.

     

How do fish ectoparasites Argulus spp. (Crustacea: Branchiura) match with their hosts at the behavioural and ecological scales?

Features of the Argulus foliaceus and A. coregoni life cycles including spatial distribution and hatching patterns of the resting eggs as well as their host searching behaviour were analyzed on the basis of field and experimental data obtained in lakes and a fish farm in the Central Finland. Published data on behaviour and ecology of these parasites were also used. The main point of this analysis was an ecological adjustment of the life cycles of parasites to that of their fish hosts at different spatial and temporal scales. Due to different spatial distribution of overwintering eggs, the newly hatched larvae of A. coregoni are more likely to attach to salmonids, which are their main hosts, while A. foliaceus to percids and cyprinids. The main peak of argulid hatching occurs in late spring-early summer and coincides with the period when most of freshwater fishes concentrate close to the shore, either for spawning, or, foraging. Nevertheless, despite the general coincidence, the parasite-host encounter rate could still be very low. The main peak of hatching is followed by a long "tail". We suggest that under fluctuating and uncertain environmental conditions characterised by both abiotic stochasticity and poor predictability of the hosts, an optimal recruitment strategy is to hedge a bet, with a proportion of eggs synchronously hatching and a proportion remaining dormant and hatching at much lower rate during an extended period. One of the main behavioural adaptations to match with the hosts is all-over-the-day searching activity of argulids. The boreal A. coregoni relies primarily on vision, which is most effective in transparent waters during long polar days in summer. Vision is also important in the behavioural repertoire of the temperate A. foliaceus in the light, but olfaction and mechanoreception in the dark provide the highest host searching rate. The two generally sympatric species of argulids segregated on the finer habitat scale. Partially overlapping on salmonid hosts, they prefer ecologically distinct categories of fish, and use different microhabitats for egg laying and searching for hosts.     

Interaction mechanisms of encapsulated meningococci with eucaryotic cells: what does this tell us about the crossing of the blood-brain barrier by Neisseria meningitidis?

An important feature of Neisseria meningitidis is its ability to invade the meninges. This requires that bacteria cross the blood-brain barrier (BBB), which is one of the tightest barriers of the body. N. meningitidis has, therefore, evolved very sophisticated means by which it circumvents the physical properties of this cellular barrier. Recent advances have allowed the identification of several steps that might occur in the interaction of N. meningitidis with the BBB and the transit of the bacteria to the meninges.     

Control of the eutrophication of the reservoir of Esch-sur-S?re (Luxembourg): evaluation of the phosphorus removal by predams

The phosphorus retention capacity was established for two predams having the same water supply and the same seasonality but with contrasting hydraulic retention times and phosphorus loads. The annual retention of total phosphorus of the shallow Misère predam amounted to about 60%, whereas the deeper Bavigne predam retained about 82%; for soluble reactive phosphorus (SRP) the annual retention rates were 4 and 54%, respectively. The different behaviour of the predams is probably due to their different flow regimes and morphology. The highest retention rates were observed during summer, when up to 90% of SRP could be retained in the Bavigne predam. The comparison of the measured removal rates of SRP with those calculated on the basis of the model proposed by Benndorf & Pütz (Wat. Res. 1987 21: 829–838) shows a rather good agreement for the thermally stratified Bavigne predam. For the shallow Misère predam, the model adequately predicts the annual trends of SRP removal, but a great discrepancy is observed for the absolute values. This is probably due to the phytoplankton composition and to the release of phosphorus from the sediments in the summer period.     

Nitrous Oxide (N2O) Emissions by Termites: Does the Feeding Guild Matter?

In the tropics, termites are major players in the mineralization of organic matter leading to the production of greenhouse gases including nitrous oxide (N₂O). Termites have a wide trophic diversity and their N-metabolism depends on the feeding guild. This study assessed the extent to which N₂O emission levels were determined by termite feeding guild and tested the hypothesis that termite species feeding on a diet rich in N emit higher levels of N₂O than those feeding on a diet low in N. An in-vitro incubation approach was used to determine the levels of N₂O production in 14 termite species belonging to different feeding guilds, collected from a wide range of biomes. Fungus-growing and soil-feeding termites emit N₂O. The N₂O production levels varied considerably, ranging from 13.14 to 117.62 ng N₂O-N d^-1 (g dry wt.)^-1 for soil-feeding species, with Cubitermes spp. having the highest production levels, and from 39.61 to 65.61 ng N₂O-N d^-1 (g dry wt.)^-1 for fungus-growing species. Wood-feeding termites were net N₂O consumers rather than N₂O producers with a consumption ranging from 16.09 to 45.22 ng N₂O-N d^-1 (g dry wt.)^-1. Incubating live termites together with their mound increased the levels of N₂O production by between 6 and 13 fold for soil-feeders, with the highest increase in Capritermes capricornis, and between 14 and 34 fold for fungus-growers, with the highest increase in Macrotermes muelleri. Ammonia-oxidizing (amoA-AOB and amoA-AOA) and denitrifying (nirK, nirS, nosZ) gene markers were detected in the guts of all termite species studied. No correlation was found between the abundance of these marker genes and the levels of N₂O production from different feeding guilds. Overall, these results support the hypothesis that N₂O production rates were higher in termites feeding on substrates with higher N content, such as soil and fungi, compared to those feeding on N-poor wood.     

Propylbenzmethylation at Val-1(α) markedly increases the tetramer stability of the PEGylated hemoglobin: A comparison with propylation at Val-1(α)

Background

Hemoglobin (Hb)-based oxygen carriers (HBOCs) are potential pharmaceutical agents that can be used in surgery or emergency medicine. PEGylation can modulate the vasoactivity of Hb and is a widely used approach to develop HBOCs. However, PEGylation can significantly enhance the tetramer–dimer dissociation of Hb, which may perturb the structure of Hb and increase its observed adverse effect. Thus, it is necessary to increase the tetramer stability of the PEGylated Hb.

Methods

Propylbenzmethylation at Val-1(α) of HbA was carried out to stabilize the Hb tetramer. The propylbenzmethylated Hb at Val-1(α) (PrB-Hb) was used as the starting material for site-specific PEGylation at Cys-93(β) of Hb using maleimide PEG. Structural and functional properties, autoxidation rate and thermal stability of the resultant product (PEG-PrB-Hb) were measured.

Results

Propylbenzmethylation at Val-1(α) led to 25-fold and 24-fold decreases in the tetramer–dimer dissociation constant of HbA and PEG-Hb, respectively. The increased tetramer stability is due to the enhanced hydrophobicity of the area around Val-1(α) and the increased polar interaction of Hb upon propylbenzmethylation. Thus, the structural and functional properties of PEG-Hb were improved, and its autoxidation rate and thermal denaturation were decreased.

Conclusion

Propylbenzmethylation at Val-1(α) showed higher ability than propylation at Val-1(α) to improve the structural and functional properties and decrease the side effect of PEG-Hb.

General significance

Our study can facilitate the biotechnological development of stable PEGylated Hb as more advanced HBOC. Our study is also expected to improve the stability of the tetrameric or dimeric proteins (e.g., uric oxidase) by propylbenzmethylation at their N-terminus.     

The presence of the recurrent veinlet in the?Middle Jurassic Nymphidae (Neuroptera): a unique character?condition in Myrmeleontoidea

A well-developed recurrent veinlet is found in the forewing of two species of Nymphidae from the Middle Jurassic locality of Daohugou (Inner Mongolia, China), Liminympha makarkini Ren & Engel and Daonymphes bisulca gen. et sp. n. This is the first record of this trait in the clade comprised of the superfamilies Myrmeleontoidea and Chrysopoidea. We interpret the recurrent veinlet in these species as a remnant of the condition present more basally in the psychopsoid + ithonoid + chrysopoid + myrmeleontoid clade (i.e., as a plesiomorphy). Other venational character states of Daonymphes bisulca of interest include the configuration of subcosta anterior (ScA), which is very similar to that of extant Nymphidae. We consider the short ScA terminating on ScP to be an autapomorphy of Neuroptera.     

Understanding the spectacular failure of DNA barcoding in willows (Salix): Does this result from a trans‐specific selective sweep?

Willows (Salix: Salicaceae) form a major ecological component of Holarctic floras and consequently are an obvious target for a DNA‐based identification system. We surveyed two to seven plastid genome regions (~3.8 kb; ~3% of the genome) from 71 Salix species across all five subgenera, to assess their performance as DNA barcode markers. Although Salix has a relatively high level of interspecific hybridization, this may not sufficiently explain the near complete failure of barcoding that we observed: only one species had a unique barcode. We recovered 39 unique haplotypes, from more than 500 specimens, that could be partitioned into six major haplotype groups. A unique variant of group I (haplotype 1*) was shared by 53 species in three of five Salix subgenera. This unusual pattern of haplotype sharing across infrageneric taxa is suggestive of either a massive nonrandom coalescence failure (incomplete lineage sorting), or of repeated plastid capture events, possibly including a historical selective sweep of haplotype 1* across taxonomic sections. The former is unlikely as molecular dating indicates that haplotype 1* originated recently and is nested in the oldest major haplotype group in the genus. Further, we detected significant non‐neutrality in the frequency spectrum of mutations in group I, but not outside group I, and demonstrated a striking absence of geographical (isolation by distance) effects in the haplotype distributions of this group. The most likely explanation for the patterns we observed involves recent repeated plastid capture events, aided by widespread hybridization and long‐range seed dispersal, but primarily propelled by one or more trans‐species selective sweeps.     

Habitat quality affects the condition of Luciobarbus sclateri in the Guadiamar River (SW Iberian Peninsula): effects of disturbances by the toxic spill of the Aznalc��llar mine

This study analyzes the somatic condition of southern Iberian barbel Luciobarbus sclateri (Günther, 1868) in the Guadiamar River (SW Iberian Peninsula). This river was seriously affected by a toxic spill of about 4?million cubic meters of acidic water and 2?million cubic meters of mud rich in heavy metals. Once the spill removal works concluded, sites affected and unaffected by the accident were sampled to study its effects on the fish fauna. The ecological variables registered were related to water quality, physical state of reaches, ecological quality, resources exploited by fish, and potential intra-specific interactions. From an initial 15 ecological variables, seasonal water flow and pH explained most of the variation in barbel condition. This study shows that the Guadiamar River, 56?months after the accident, is still undergoing a recovery process where, beyond ecological variables, proximity to the affected area is the most influential factor for fish condition.     

Protein tyrosine phosphatase (PTP) inhibition enhances chromosomal stability after genotoxic stress: Decreased chromosomal instability (CIN) at the expense of enhanced genomic instability (GIN)?

Inappropriate survival signaling after DNA damage may facilitate clonal expansion of genetically compromised cells, and it is known that protein tyrosine phosphatase (PTP) inhibitors activate key survival pathways. In this study we employed the genotoxicant, hexavalent chromium [Cr(VI)], which is a well-documented carcinogen of occupational and environmental concern. Cr(VI) induces a complex array of DNA damage, including DNA double strand breaks (DSBs). We recently reported that PTP inhibition bypassed cell cycle arrest and abrogated Cr(VI)-induced clonogenic lethality. Notably, PTP inhibition resulted in an increase in forward mutations at the HPRT locus, supporting the hypothesis that PTP inhibition in the presence of DNA damage may lead to genomic instability (GIN), via cell cycle checkpoint bypass. The aim of the present study was to determine the effect of PTP inhibition on DNA DSB formation and chromosomal integrity after Cr(VI) exposure. Diploid human lung fibroblasts were treated with Cr(VI) in the presence or absence of the PTP inhibitor, sodium orthovanadate, for up to 24h, and cells were analyzed for DNA DSBs and chromosomal damage. Cr(VI) treatment induced a rapid increase in DNA DSBs, and a significant increase in total chromosomal damage (chromatid breaks and gaps) after 24h. In sharp contrast, PTP inhibition abrogated both DNA DSBs and chromosomal damage after Cr(VI) treatment. In summary, PTP inhibition in the face of Cr(VI) genotoxic stress decreases chromosomal instability (CIN) but increases mutagenesis, which we postulate to be a result of error-prone DNA repair.     

Do gut symbiotes reflect the endemism of their host black flies (Diptera: Simuliidae) in the Caucasus of Armenia?

Aim We tested the hypothesis that endemism of black flies in the Caucasus of Armenia is reflected in their gut symbiotes, i.e. trichomycete fungi and ichthyosporean protists. Location The study area, Armenia, is a biodiversity hotspot, with high levels of plant and animal endemism. Located in the southern Caucasus, Armenia is a rugged, mountainous, landlocked country of 29,800 km², with fast‐flowing rivers and little forested land. About half of the 51 species of black flies in Armenia are endemic to the Caucasus. Methods The larvae of 22 species of black flies, including seven endemic to the Caucasus, were collected from 35 sites throughout Armenia, from 1998 to 2004, and assayed microscopically for gut‐inhabiting trichomycete fungi and ichthyosporean protists. Results Nearly 68% of larval black flies in Armenia contained at least one species of gut symbiote, with a mean of 0.9 ± 0.04 species per host larva. Eight species of trichomycete fungi and two species of ichthyosporeans were found in larval guts. Seven of these species were recorded for the first time in Asian black flies. Species accumulation curves showed no additional species of gut symbiotes after 17 host species and 22 sites had been examined. All gut symbiotes were widely distributed, indicating an absence of endemic trichomycetes in the black flies of Armenia. Main conclusions Although the Caucasus Region is noted for its high levels of endemism for plants and animals, including black flies, the gut symbiotes of black flies are all widespread species. The absence of endemic gut symbiotes in larval black flies might be explained by their lack of host specificity; an absence of host specificity would not constrain the geographical distribution of the symbiotes.