Characterization of 16 microsatellite loci for a common coral reef fish,the fierce shrimpgoby Ctenogobiops feroculus

We developed 16 pairs of primers for microsatellite loci of the fierce shrimpgoby, Ctenogobiops feroculus. Analysis of 35–40 gobies per locus from five islands in French Polynesia indicated that allele frequency varied from two to 30 per locus, while observed heterozygosity ranged between 0.05 and 0.98. These microsatellites should provide insight into patterns of dispersal and connectivity among populations of this common coral reef fish.     

Endophytic fungi decrease available resources for the aphid Rhopalosiphum padi and impair their ability to induce defences against predators

Abstract.  1. The production of winged morphs is a well known mechanism of induced defence in aphids to escape from natural enemies, and is also a reaction to poor resource quality.
2. Host plants of aphids often associate with endophytic fungi that have been shown to reduce the fitness of some species of aphids.
3. It was hypothesised that endophyte infection of host plants that represent a low quality plant resource should increase the aphid's induced response to a predator because both low plant quality and predator presence represent a stronger cue for wing production than predator presence alone.
4. In a laboratory experiment, bird cherry-oat aphids Rhopalosiphum padi L. were exposed to the factors predator threat and endophyte infection and the effects of these factors on the proportion of winged morphs produced by the aphid colonies was analysed.
5. The presence of endophytic fungi strongly decreased aphid colony sizes. When a predator threat was present, all colonies on endophyte-free grasses produced winged morphs whereas only a few colonies were able to produce winged morphs on endophyte-infected grasses. However, these few colonies produced larger proportions of winged morphs than colonies on endophyte-free grasses. Without a predator threat, no colonies on endophyte-infected grasses produced any winged morphs.
6. These results show that aphids in stressed conditions and with reduced fitness will only invest in inducible defences when predators are present but are unable to produce winged morphs in response to endophyte presence.     

A mitochondrial genome phylogeny of Diptera: whole genome sequence data accurately resolve relationships over broad timescales with high precision

Abstract Mitochondrial genomes provide a promising new tool for understanding deep‐level insect phylogenetics, but have yet to be evaluated for their ability to resolve intraordinal relationships. We tested the utility of mitochondrial genome data for the resolution of relationships within Diptera, the insect order for which the most data are available. We sequenced an additional three genomes, from a syrphid, nemestrinid and tabanid, representing three additional dipteran clades, ‘aschiza’, non‐heteroneuran muscomorpha and ‘basal brachyceran’, respectively. We assessed the influence of optimality criteria, gene inclusion/exclusion, data recoding and partitioning strategies on topology and nodal support within Diptera. Our consensus phylogeny of Diptera was largely consistent with previous phylogenetic hypotheses of the order, except that we did not recover a monophyletic Muscomorpha (Nesmestrinidae grouped with Tabanidae) or Acalyptratae (Drosophilidae grouped with Calliphoridae). The results were very robust to optimality criteria, as parsimony, likelihood and Bayesian approaches yielded very similar topologies, although nodal support varied. The addition of ribosomal and transfer RNA genes to the protein coding genes traditionally used in mitochondrial genome phylogenies improved the resolution and support, contrary to previous suggestions that these genes would evolve too quickly or prove too difficult to align to provide phylogenetic signal at deep nodes. Strategies to recode data, aimed at reducing homoplasy, resulted in a decrease in tree resolution and branch support. Bayesian analyses were highly sensitive to partitioning strategy: biologically realistic partitions into codon groups produced the best results. The implications of this study for dipteran systematics and the effective approaches to using mitochondrial genome data are discussed. Mitochondrial genomes resolve intraordinal relationships within Diptera accurately over very wide time ranges (1–200 million years ago) and genetic distances, suggesting that this may be an excellent data source for deep‐level studies within other, less studied, insect orders.     

Multi-scale phenotyping of leaf expansion in response to environmental changes: the whole is more than the sum of parts

The leaf is a multi-scale dynamic unit that is determined by mechanisms at different organizational scales (cell, tissue, whole leaf and whole plant) and affected by both internal (genotype) and external (environmental) determinisms. The recent development of phenotyping platforms and imaging techniques provides new insights into the temporal and spatial patterns of leaf growth as affected by those determinisms. Conclusions about the overriding mechanisms often depend on the considered organizational scale and of time resolution which varies from minutes to several weeks. Analyses of leaf growth responses to environmental conditions have revealed robust emerging properties at whole plant or whole leaf scales. They have highlighted that the control of individual leaf expansion is more complex than merely the sum of cellular processes, and the control at the whole plant level is more complex than the sum of individual leaf expansions. However, in many cases, the integrated leaf-growth variable can be simplified to a limited set of underlying variables to be measured for comparative analyses of leaf growth or modelling purposes.     

Effectiveness of Short-Distance Translocation and its Effects on Western Rattlesnakes

ABSTRACT Short-distance translocation (SDT) is commonly used to mitigate snake-human interactions, yet little is known about its effectiveness or its effects on behavior and welfare of snakes. Between April 2004 and October 2005, we evaluated SDT as a conservation and management tool by investigating how 500-m SDT affected spatial ecology, body condition, and behavior of western rattlesnakes (Crotalus oreganus) surgically implanted with radiotransmitters in a field study near Osoyoos, British Columbia, Canada. Of 14 rattlesnakes subjected to SDT, 12 (85.7%) returned on ≥1 occasion (range 1–7 times) to the general area they were removed from. Rattlesnakes that underwent SDT showed an increase in total distance moved over an active season compared to non-translocated snakes, but there was no evidence to suggest SDT had an effect on activity range size. There was no evidence to suggest SDT affected body condition, behavior, or mortality rates. Short-distance translocation to high-quality undisturbed habitats was unsuccessful as a long-term solution to snake-human conflict because most translocated snakes returned to conflict areas within a short time (x̄x = 19.9 ± 8.7 days). However, SDT may be an effective short-term tool to manage snake-human conflict in areas where human presence is seasonal or short-lived if careful attention is paid to species-specific biological needs, habitat quality at the release site, and the location of the release site in relation to conflict areas.     

Benthic metabolism in two turbid dryland rivers

1. Australian dryland rivers have among the most variable discharge of any rivers worldwide and are characterized by extended periods of no flow during which aquatic habitat contracts into isolated waterholes. Despite naturally high turbidity, benthic primary production is known to be the main source of carbon to waterhole food webs. The objective of this study was to quantify rates of benthic metabolism and identify factors influencing these rates in two Australian dryland rivers, the Cooper Creek and the Warrego River. 2. Both rivers have similar variable hydrology and high levels of turbidity (photic depths < 0.4 m), but fish abundance in Cooper Creek is 10 times than that of the Warrego River. Therefore, an additional aim of the study was to determine if fish abundances reflected underlying differences in benthic primary production. 3. Benthic gross primary production (GPP), benthic respiration, nutrient concentrations and light penetration were measured immediately after flow had ceased (‘post‐flow’) and after at least 2 months of zero flow (‘no‐flow’) in 15 waterholes from each river. A subset of four waterholes from each river was sampled on two additional occasions to determine if patterns were consistent over time. 4. Cooper Creek generally had higher rates of GPP and a more autotrophic benthic zone than the Warrego River. As a result, the expected positive relationship between fish abundance and GPP was generally observed at a broad catchment scale. 4. Light was the major control in benthic GPP in both rivers, as nutrient concentrations were high on all sampling occasions. However, for similar values of photic depth, GPP was greater in Cooper Creek than in the Warrego River. This suggests that more frequent disturbance of the littoral zone may inhibit biofilm development in waterholes of the Warrego River. 5. Although flow variability in dryland rivers is extreme compared with other rivers worldwide, cycles of expansion and contraction of aquatic habitat in these two rivers were associated with a shift in the dominance of regional scale (subcatchments contributing to river flow) versus local scale (waterhole morphology) influences on ecosystem functioning, similar to floodplain rivers in tropical and temperate regions.