Population genetic and behavioural variation of the two remaining colonies of Providence petrel (<Emphasis Type="Italic">Pterodroma solandri</Emphasis>)

Knowledge of the dispersal capacity of species is crucial to assess their extinction risk, and to establish appropriate monitoring and management strategies. The Providence petrel (Pterodroma solandri) presently breeds only at Lord Howe Island (~32,000 breeding pairs) and Phillip Island-7 km south of Norfolk Island (~20 breeding pairs). A much larger colony previously existed on Norfolk Island (~1,000,000 breeding pairs) but was hunted to extinction in the 18th Century. Differences in time of return to nesting sites are presently observed between the two extant colonies. Information on whether the Phillip Island colony is a relict population from Norfolk Island, or a recent colonization from Lord Howe Island, is essential to assess long-term sustainability and conservation significance of this small colony. Here, we sequenced the mitochondrial cytochrome b gene and 14 nuclear introns, in addition to genotyping 10 microsatellite loci, to investigate connectivity of the two extant P. solandri populations. High gene flow between populations and recent colonization of Phillip Island (95 % HPD 56–200 ya) are inferred, which may delay or prevent the genetic differentiation of these insular populations. These results suggest high plasticity in behaviour in this species and imply limited genetic risks surrounding both the sustainability of the small Phillip Island colony, and a proposal for translocation of Lord Howe Island individuals to re-establish a colony on Norfolk Island.     

Diurnal patterns of airborne algae in the Hawaiian Islands: a preliminary study

Although the literature on the diversity of airborne algal communities in various locations around the world is increasing, little is known about their temporal and spatial patterns. We compared airborne algal communities from Honolulu, Hawai‘i, USA, over three 24-h sampling periods to examine diurnal patterns in diversity and abundance. Using a culture-based approach, 192 algal colonies were characterized and identified as 31 operational taxonomic units. A combination of microscopy and Sanger sequencing (of the UPA marker) was used for characterizations. More airborne algal colonies were identified from nighttime collections (127 of 192 colonies) than daytime collections (65 of 192 colonies) (p?<?0.0001). Similarly, 95% of the daytime collections were Cyanobacteria, and 87% of the nighttime collections were Chlorophyta, and the trends of more Cyanobacteria being collected during the day and more Chlorophyta at night were significant (p?<?0.0001). Meteorological analyses for the sampling periods indicated that air masses sampled during the three trials consistently arrived in the Hawaiian Islands on a northeast trade wind pattern, but with different origins in the Pacific Ocean, and that low-to-trace levels of rain fell during the sampling periods. Land breeze and sea breeze effects, which are common temperature-driven phenomena on tropical islands, may have played a role in the diurnal pattern observed in the current study.     

In situ growth rates of deep-water octocorals determined from 3D photogrammetric reconstructions

Growth rates of deep-water corals provide important information on the recovery potential of these ecosystems, for example from fisheries-induced impacts. Here, we present in situ growth dynamics that are currently largely unknown for deep-water octocorals, calculated by applying a non-destructive method. Videos of a boulder harbouring multiple colonies of Paragorgia arborea and Primnoa resedaeformis in the Northeast Channel Coral Conservation Area at the entrance to the Gulf of Maine at 863 m depth were collected in 2006, 2010 and 2014. Photogrammetric reconstructions of the boulder and the fauna yielded georeferenced 3D models for all sampling years. Repeated measurements of total length and cross-sectional area of the same colonies allowed the observation of growth dynamics. Growth rates of total length of Paragorgia arborea decreased over time with higher rates between 2006 and 2010 than between 2010 and 2014, while growth rates of cross-sectional area remained comparatively constant. A general trend of decreasing growth rates of total length with size of the coral colony was documented. While no growth was observed for the largest colony (165 cm in length) between 2010 and 2014, a colony 50–65 cm in length grew 3.7 cm yr^?1 between 2006 and 2010. Minimum growth rates of 1.6–2.7 cm yr^?1 were estimated for two recruits (<23 cm in 2014) of Primnoa resedaeformis. We successfully extracted biologically meaningful data from photogrammetric models and present the first in situ growth rates for these coral species in the Northwest Atlantic.     

The influence of a seabird colony on abundance and species composition of water bears (Tardigrada) in Hornsund (Spitsbergen,Arctic)

Seabirds in the Arctic are known to link marine and terrestrial ecosystems. They feed in the sea and breed on land, where they deposit enormous amounts of guano. Soil in the vicinity of seabird colonies is much more enriched with nutrients as compared to areas beyond their impact, which positively affects primary and secondary production. Water bears (Tardigrada) are microinvertebrates which constitute a permanent and ubiquitous faunal component of polar regions. Here, we tested the influence of seabird guano on Tardigrada communities; we established two transects in Hornsund (SW Spitsbergen): (1) SEABIRD where little auks (Alle alle) nested, and (2) CONTROL, an area without a little auk colony. In total, we collected 160 moss, lichen and mixed (moss/lichen) samples from those areas. In total, we found 1990 specimens belonging to 32 taxa (25 identified to species level). The average density of water bears was higher in the SEABIRD transect (9.31 ind g^?1), where mosses predominated over lichens, in comparison with the CONTROL transect (5.83 ind g^?1), where more lichens occurred. Thus, ornithogenic enrichment of soil and locally facilitated development of mosses over lichens might be important factors responsible for the increase in invertebrate abundance. According to canonical correspondence analysis, the little auk colony effect explained 13.2 % of the tardigrade species composition, and this factor appeared to be more important than the vegetation type itself. Four taxa, i.e. Isohypsibius cf. reticulatus, Microhypsibius bertolanii, Minibiotus cf. formosus and Ramazzottius cf. rupeus, have been recorded in the Svalbard archipelago for the first time.     

Extraordinary abundance of hydrocorals (Cnidaria,Hydrozoa, Stylasteridae) in shallow water of the Patagonian fjord region

During two scuba-diving expeditions in 2005 and 2006, stylasterids were documented and sampled from fjords and channels in the Central Patagonian Zone, Chile. At 15 of a total of 33 sampling sites we found colonies of Errina antarctica. We discuss the observed distribution patterns and the variability of colony shapes. In some regions we found E. antarctica to occur in extraordinary high densities on primary and secondary hard substratum below 10 m. In the archipelago Madre de Dios we discovered large colonies of E. antarctica covering areas of more than 10,000 m² with coverage exceeding 80%. The dense accumulations of E. antarctica have reef-like structure and form complex habitats. At one site we observed extensive mechanical damage to the corals that may result from coral extraction by divers and/or from boat anchors. Slow growth, fragility, scarceness and the lack of knowledge on their ecology make these spectacular and unique biocenoses very susceptible for damages and require protection and further studies.     

Trans-generational specificity within a cnidarian–algal symbiosis

Ocean warming and other anthropogenic stresses threaten the symbiosis between tropical reef cnidarians and their dinoflagellate endosymbionts (Symbiodinium). Offspring of many cnidarians acquire their algal symbionts from the environment, and such flexibility could allow corals to respond to environmental changes between generations. To investigate the effect of both habitat and host genotype on symbiont acquisition, we transplanted aposymbiotic offspring of the common Caribbean octocoral Briareum asbestinum to (1) an environmentally different habitat that lacked B. asbestinum and (2) an environmentally similar habitat where local adults harbored Symbiodinium phylotypes that differed from parental colonies. Symbiont acquisition and establishment of symbioses over time was followed using a within-clade DNA marker (23S chloroplast rDNA) and a within-phylotype marker (unique alleles at a single microsatellite locus). Early in the symbiosis, B. asbestinum juveniles harbored multiple symbiont phylotypes, regardless of source (parent or site). However, with time (~4 yr), offspring established symbioses with the symbiont phylotype dominant in the parental colonies, regardless of transplant location. Within-phylotype analyses of the symbionts revealed a similar pattern, with offspring acquiring the allelic variant common in symbionts in the parental population regardless of the environment in which the offspring was reared. These data suggest that in this host species, host–symbiont specificity is a genetically determined trait. If this level of specificity is widespread among other symbiotic cnidarians, many cnidarian–algal symbioses may not be able to respond to rapid, climate change-associated environmental changes by means of between-generation switching of symbionts.     

Genetic relationships within colonies suggest genetic monogamy in the Eurasian beaver (<Emphasis Type="Italic">Castor fiber</Emphasis>)

Social monogamy, considered rare in mammals, has been described in two species of beaver, the Eurasion beaver (Castor fiber), and the North American beaver (Castor Canadensis). Social monogamy, however, does not necessarily imply genetic monogamy. For example, in group living mammals, females may engage in extra-pair copulations as a result of increased female mate choice opportunities. Recently, following genetic analysis, a wide range of genetic relationships among colony members have been documented in the North American beaver, including extra-pair paternity. Here, we used microsatellite loci to provide parentage estimates from colonies of the Eurasian beaver in the Kirov region, Russia. No evidence for the presence of any extra-pair young was detected. However, in two cases, we found a pair of unrelated males inhabiting a single colony. Our results suggest that while colonies may comprise both related and unrelated individuals, the genetic mating system appears to match that of the previously inferred social monogamy.     

Cryptic species of cardinalfish with evidence for old and new divergence

Larval dispersal and limited knowledge of physical boundaries challenge our understanding of the processes that drive genetic divergence and potential speciation in the marine environment. Divergence, both within and between populations of marine taxa, is not uncommon, but spatial and temporal stability of observed genetic structure is not well known. Previously, we detected large genetic differences among populations of the cardinalfish species Ostorhinchus doederleini inhabiting adjacent coral reefs. Here, we determined the spatial and temporal persistence of these genetic structures over the course of ten consecutive generations. Using microsatellite markers, we detected large changes (genetic population distance, D _est, ranged from 0.04 to 0.46) in the genetic structure in some years, but some reefs maintained the same populations for nearly all sampling years. As this species’ life span does not exceed 1 yr, persistence of distinct reef populations suggests natal homing. Mitochondrial identity based on two mtDNA markers corroborates the nuclear genetic evidence for genetic differences large enough to constitute different clades and even cryptic species in O. doederleini, which, based on gross morphology, was thought to be a single taxon. Habitat specialization was observed in one clade that exclusively inhabited reef lagoons, while all clades could be observed on reef slopes. We suggest that local habitat recognition combined with local population recognition and selection against hybrids can form barriers that maintain a cryptic species complex.     

The advertising display of double-crested cormorants varies with microhabitat and time of the season in a tree-nesting colony

Male double-crested cormorants (Phalacrocorax auritus) perform advertising displays at potential nest locations at spring breeding grounds to attract females. Yet, there is no research on how the frequency of this behaviour changes over time or its association with habitat features. Studies of this behavioural display may provide insight into how birds choose areas for nesting, an important issue given the environmental and societal impacts of dense colonies of cormorants. Advertising behaviour was observed in trees throughout the 2014 nesting season, at six different sampling stations, using both scan sampling (for temporal changes in display frequency) and focal sampling (for temporal changes in four microhabitat variables: tree health, height in tree, nest density and presence of a nest). Advertising data (scans N = 484 birds; focal samples N = 827 birds) were divided into pre-incubation, incubation and chicks-present categories using a breeding chronology dataset. The number of cormorants advertising varied temporally and spatially. Using scan data in a marginal model, we found that the number of cormorants advertising was highest at the beginning of the season (peaking at week 3) and lowest once chicks were present. The GLM (focal data) showed that most cormorants advertised without nests especially past the second week of the season. The model also indicated that cormorants advertised in low nest density trees from pre- to mid-incubation. Contrary to our predictions based on colony expansion over the season, we did not observe an interaction of tree health*time or station*time, which suggests that the advertising display revealed a nest site selection process that was not visible at the population level.     

Lagged Population Growth in a Termite Host Colony: Cause or Consequence of Inquilinism?

The presence of foreign organisms in the colonies of social insects could affect energy allocation to growth and reproduction of these hosts. Highly specialized invaders of such long-lived hosts, however, can be selected to be less harmful. After all, it pays for these symbionts to keep their host’s good health thereby prolonging cohabitation in the homeostatic environment of the termite colony. Here, we investigated such a hypothesis, focusing on populational parameters of a termite host sharing its nest with an obligatory termite inquiline. To this end, 19 natural colonies of Constrictotermes cyphergaster (Silvestri, 1901) (Termitidae: Nasutitermitinae) were sampled and the (i) number of individuals, (ii) proportion of soldier/workers in the colonies, and (iii) presence/absence of obligatory inquiline Inquilinitermes microcerus (Silvestri, 1901) (Termitidae: Termitinae) were measured. Results revealed a negative correlation between the number of individuals and the proportion of soldier/workers in the host colonies with the presence of I. microcerus colonies. In search of causal mechanisms for such a correlation, we inspected life history traits of both, inquilines and hosts, hypothesizing that such a result could indicate either (i) a dampening effect of the inquiline upon its host population or (ii) the coincidence of the moment of inquiline infiltration with the natural reduction of C. cyphergaster populational growth at the onset of its reproductive phase.     

The Role of Resource Density on Energy Allocation in the Neotropical Termite <Emphasis Type="Italic">Nasutitermes</Emphasis> aff. <Emphasis Type="Italic">coxipoensis</Emphasis> (Termitidae: Nasutitermitinae)

Organisms acquire energy from environment and must allocate it among different life traits (growth, maintenance and reproduction). Social insects must manage the energy allocation to various levels such as colony growth and caste functions. Here, we addressed the question of whether resource density affects the energy allocation to the number of individuals and caste functions as well as nest’s growth rate in the Neotropical termite Nasutitermes aff. coxipoensis (Homgren) (Termitidae: Nasutitermitinae). In a manipulative field experiment, colonies of N. aff. coxipoensis, with known volume, were maintained in plots with three different resource’s density (0.32, 0.64 and 1.92 baits/m²) over 3 months. After this period, the number of individuals as well as the caste identity and nest volume were measured. Surprisingly, our results showed that colonies reared in the extremes of resource’s density (0.32 and 1.92 baits/m²) produced a higher number of individuals compared with colonies reared with intermediate resource density (0. 64 baits/m²). The mean number of workers increased linearly with resource density; however, the average number of immature was higher in colonies reared with 0.32 baits/m² compared with colonies reared with 0.64 and 1.92 baits/m². No significant differences of resource density were observed in the mean number of soldiers, worker/soldier ratio as well as in the nest’s growth rate. In conclusion, the resource’s density seems to play an important role in determining the investment of energy in the number of individuals and caste in N. aff. coxipoensis colonies.     

Foraging habitats and floral resource use by colonies of long- and short-tongued bumble bee species in an agricultural landscape with kabocha squash fields

Bumble bees pollinate and forage on flowers of crop and wild plants in agricultural landscapes. These interactions may depend on landscape patterns and bumble bee traits. We studied the abundance, colony density, and foraging range in long-tongued Bombus diversus Smith and short-tongued B. hypocrita Pérez, and evaluated their visits to flowers of wild plants and cultivated kabocha squash (Cucurbita maxima Duchesne). In forests in a farmland, B. hypocrita workers were trapped more frequently in the canopy. Full-sibs determined by nuclear microsatellite genotypes among workers collected in the farmland showed higher colony density and a larger foraging radius in B. hypocrita (30.8 km^?2 and 848 m) than in B. diversus (8.3 km^?2 and 723 m), respectively. Regarding wild plants, workers more frequently visited shallow flowers in B. hypocrita and deep flowers in B. diversus. These results suggest that bumble bees with different traits forage on different wild flowers in different habitats. Squash flowers were visited by both bumble bee species at similar frequency in the latter period of colony growth when males and new queens appeared. Composition of full-sib workers visiting squash and wild flowers did not depend on the number of collected workers of individual colonies, indicating that foraging on squash flowers was not associated with colony growth. Thus, growth and reproduction of bumble bee colonies may be supported by various wild plants and cultivated squash, respectively.     

A spreading colony formed method for rapid evaluation of dicarboximide fungicides resistance level of field tobacco brown spot disease

A new method (spreading colony formed method) for rapidly identifying and evaluating the dicarboximide fungicides resistance level of field tobacco spot brown disease caused byAlternaria longipes was developed. Two typical colonies with distinct differences in colony morphology on media containing 5 μg/ml dicarboximide fungicides dimethachlon (CAS registration number: 24096-53-5) were discovered by using this method. The two typical colonies were named spreading colony and dense pad colony, respectively. Isolates (250) ofA. longipes were quickly separated by this method, and their growth properties (including the sensitivity to dimethachlon, the cross-resistance to phenylpyrroles fludioxonil and hyphal development) were examined. Our results indicated that (1) monospore isolates from spreading colonies and dense pad colonies were respectively resistant and sensitive to dimethachlon; (2) resistant and sensitive isolates formed respectively spreading colonies and dense pad colonies on dimethachlon media. Furthermore, molecular experiments confirmed the spreading colony formed method reliable. In conclusion, field resistant isolates and resistant situation in population level of field tobacco spot brown disease could be exactly and timely determined and evaluated by spreading colony formed method.     

Colony genetic organization and colony fusion in the termite Reticulitermes flavipes as revealed by foraging patterns over time and space

Temporal and spatial analyses are seldom utilized in the study of colony genetic structure, but they are potentially powerful methods which can yield novel insights into the mechanisms underlying variation in breeding systems. Here we present the results of a study which incorporated both of these dimensions in an examination of genetic structure of subterranean termites in the genus Reticulitermes (primarily R. flavipes). Most colonies of this species (70%) were simple families apparently headed by outbred primary reproductives, while most of the remaining (27% of the total) colonies contained low effective numbers of moderately inbred reproductives. Mapping the spatial distribution of colony foraging sites over time revealed that despite the high colony density, the absolute foraging boundaries of most R. flavipes colonies were persistent and exclusive of other conspecific colonies, which suggests that this species is more territorial than has been implied by laboratory studies of intraspecific aggression. Nevertheless, we found a single colony (3% of all colonies) which contained the offspring of more than two unrelated reproductives. Although other studies have also described subterranean termite colonies with a similarly complex genetic composition, we demonstrate here that such colonies can form under natural conditions via the fusion of whole colonies. This study underscores how repeated sampling from individual colonies over time and space can yield information about colony spatial and genetic structure that cannot be obtained from conventional analyses or sampling methods.     

Modes of colony foundation by females of different morphotypes in the paper wasps (Hymenoptera,Vespidae, <Emphasis Type="Italic">Polistes</Emphasis> Latr.)

Paper wasps of the genus Polistes exhibit wide variability both of the color and size of foundresses, and the mode of colony foundation. The colony foundation and social hierarchy were studied in populations of two Palaearctic species, Polistes dominulus (Christ) and P. nimphus (Christ) (April–May 2006, the Crimean Peninsula, Ukraine), and one Neotropical species, P. lanio (F.) (October 2004–January 2005, Trinidad Island). It was shown that foundresses of various color and size morphs tended to found nests in a peculiar way: singly (haplometrosis), by groups (pleometrosis), or occupying several nests simultaneously (polycaly). The relationship between coloration, size, and mode of colony foundation was species-specific. P. dominulus foundresses with a darker clypeus and a paler mesonotum preferred to found nests alone and had a dominant position in pleometrosis. The haplometrotic P. nimphus foundresses more often displayed darker variants of the clypeus and paler variants of the mesonotum than did foundresses from pleometrotic colonies. P. lanio foundresses from pleometrotic colonies differed from those from polycalic colonies in the coloration variability of the scutum, propodeum, and the 2nd metasomal tergite. The dominant and subordinate P. nimphus and P. lanio foundresses differed in the size of head and wings. The possible significance of the subdivision of foundresses into the “generalists” and “specialists” for the variability structuring in the population is considered.     

Soldiers are differentiated from male larval stages in incipient colonies of <Emphasis Type="Italic">Nasutitermes takasagoensis</Emphasis> (Isoptera: Termitidae)

In phylogenetically ancestral taxa of termites (the so-called lower termites), at least one soldier emerges and is maintained longitudinally in each incipient colony. However, in apical taxa (the so-called higher termites), the developmental pathway and regulation of soldiers in incipient colonies currently remain unknown. We therefore examined soldier and worker development in incipient colonies of higher termites (Nasutitermes takasagoensis Shiraki). Developmental stages and castes were successfully discriminated by head width in incipient colonies 4 months after colony foundation. Furthermore, differences were observed in the number of bristles on antennae between first- and second-instar larvae. In N. takasagoensis, there was more than one soldier in each incipient colony 4 months after its foundation. Presoldiers in the incipient colonies were differentiated from an earlier instar (male second-instar larvae), whereas, in mature colonies, they were differentiated from male third instars (= minor workers). The developmental period of the former (7 days) was markedly shorter than that of the latter (14 days). All female second-instar larvae molted into workers. The developmental processes shown here are useful for obtaining a clearer understanding of the mechanisms of soldier/worker differentiation in higher termites.     

Preventive application of an entomopathogenic fungus in cover crops for wireworm control

Efficacy of the Metarhizium brunneum Petch (Hypocreales: Clavicipitaceae) strain ART2825 for control of wireworms (Agriotes obscurus (L.), Coleoptera: Elateridae) was examined in a semi-field pot experiment. Pots were treated in late summer during sowing of spring oat as a cover crop. Survival of wireworms was assessed four weeks after their release in October 2013, and 30 weeks after release in April 2014. Viability and persistence of the fungus was determined by counting colony forming units from substrate samples and microsatellite analyses of recovered Metarhizium isolates. The number of colonies detected in the substrate in October 2013 increased with increasing concentrations of applied conidia, and no significant reduction was observed at the second evaluation date in April 2014. Increasing conidia application rates significantly increased mycosis and reduced wireworm survival, to a level comparable to that of treatment using insecticide-coated oat seeds. The preventive application of M. brunneum conidia to reduce wireworm populations in cover crops, preceding a damage-sensitive crop like potatoes, may be a promising biocontrol strategy.     

Interspecific variation in extracellular polysaccharide content and colony formation of <Emphasis Type="Italic">Microcystis</Emphasis> spp. cultured under different light intensities and temperatures

Single cells of five different Microcystis species (M. ichthyoblabe, M. viridis, M. flos-aquae, M. wesenbergii, and M. aeruginosa) were batch-cultured at different temperatures and light intensities: (a) 25 °C and 50 μmol photons m^?2 s^?1 (control culture); (b) 25 °C and 10 μmol photons m^?2 s^?1; and (c) 15 °C and 50 μmol photons m^?2 s^?1. The extracellular polysaccharide content was significantly higher in treatments b and c than in the control treatment. All Microcystis species existed as single cells under the control treatment but formed colonies in treatments b and c. All of the colonies were irregular with indistinct margins. M. ichthyoblabe, M. viridis, M. flos-aquae, and M. wesenbergii formed colonies with similar morphologies and their cells were loosely aggregated. In contrast, M. aeruginosa formed denser colonies with no distinct holes. The colony morphologies differed from the classic morphology of M. ichthyoblabe field-grown colonies but resembled that of small colonies found in Lake Taihu (Yangtze Delta Plain, China) during early spring. This indicates that field- and laboratory-grown colonies are governed by similar formation processes. We suggest that in laboratory and field environments, M. ichthyoblabe (or M. flos-aquae) colonies are representative of small colonies formed from single Microcystis cells, whereas the morphology of older colonies evolves to resemble M. wesenbergii and M. aeruginosa colonies.     

Genotyping and Persistence of <Emphasis Type="Italic">Candida albicans</Emphasis> from Pregnant Women with Vulvovaginal Candidiasis

Objective

To study Candida albicans genotypes using RAPD and their susceptibility to fluconazole in healthy pregnant women and in vulvovaginal candidiasis (VVC) patients after topical treatment with clotrimazole.

Methods

Vaginal swabs were collected at t = 0 and t = 1 (1 month later) in pregnant women (control group, n = 33), and before (t = 0), at 1 month (t = 1) and at 2 months (t = 2) after clotrimazole treatment in pregnant women with VVC.

Results

Candida albicans was isolated in 30% of healthy pregnant women and 80% of patients with VVC. A high genetic heterogeneity was observed in C. albicans genotypes between individuals. In patients with VVC, topical antifungal treatment with clotrimazole was clinically effective, but only in a 62% C. albicans was eradicated. In patients in which C. albicans was not eradicated, this microorganism persisted for 1 or 2 months after the antifungal treatment. The persistent colonies were not associated with a specific genotype, but they were associated with higher MICs in comparison with colonies isolated from the control group.

Conclusions

Therapy with topical clotrimazole, despite a good clinical outcome, could not eradicate completely C. albicans allowing the persistence of genotypes, with higher MICs to fluconazole. More studies with higher number of patients are needed to validate this preliminary finding.