Copulatory process in Oxychilus (Drouetia) atlanticus (Morelet and Drouët, 1857) (Pulmonata: Zonitidae)

Summary

Oxychilurr (Drouetia) atlanticus (Pulmonata: Zonitidae) is an endemic hermaphroditic species from São Miguel island (Azores). The copulatory process is a mutually simultaneous event and takes about 24 h from the beginning of penetration until the disconnection of the partners. Copulation is characterized by the progressive and complete evertion of the penis and penial caecum. The latter, everting completely inside the bursa copulatrix, is fundamental to the release of the anterior portion of the spermatophore, which is the first to be transferred. The anterior portion of the spermatophore is hook-shaped, aiding its anchorage to the bursa, and the posterior portion ends in a hood with an aperture through which the spermatozoa are released.     

Gold coated ferric oxide nanoparticles based disposable magnetic genosensors for the detection of DNA hybridization processes

In this article, a disposable magnetic DNA sensor using an enzymatic amplification strategy for the detection of specific hybridization processes, based on the coupling of streptavidin-peroxidase to biotinylated target sequences, has been developed. A thiolated 19-mer capture probe was attached to gold coated ferric oxide nanoparticles and hybridization with the biotinylated target was allowed to proceed. Then, a streptavidin-peroxide was attached to the biotinylated target and the resulting modified gold coated ferric oxide nanoparticles were captured by a magnetic field on the surface of a home-made carbon screen printed electrode (SPE). Using hydroquinone as a mediator, a square wave voltammetric procedure was chosen to detect the hybridization process after the addition of hydrogen peroxide. Different aspects concerning the assay protocol and nanoparticles fabrication were optimized in order to improve the sensitivity of the developed methodology. A low detection limit (31 pM) with good stability (RSD=7.04%, n=10) was obtained without the need of polymerase chain reaction (PCR) amplification.     

Assortative mating among Anastrepha fraterculus (Diptera: Tephritidae) hybrids as a possible route to radiation of the fraterculus cryptic species complex

Reproductive isolation among populations of Anastrepha fraterculus has been found acting at the pre‐ and post‐zygotic levels. Differences in timing of sexual activity and male sexual pheromone composition among populations could partially account for prezygotic isolation. Hybrid males were found to produce a novel pheromone, which is a mix of parental pheromones. In the present study, we found that the hybrid females showed a significant preference to mate with hybrid males than with parental males. Male location during pheromone emission is associated with its reproductive success and, thus, differences in the location of males during courtship could also play a role in isolation. We found evidence that reproductive isolation is also related to the location of males during courtship. Hybrid male behaviour regarding location during pheromone release was found to be influenced by the maternal lineage. If these populations hybridized in the field, the hybrid females would tend to mate with hybrid males probably leading to the formation of a new entity within the A. fraterculus complex. This simple and fast process could be one reason explaining the high number of taxonomic entities within this complex. Further studies on other members of the fraterculus species group may reveal whether this can be considered as an example of homoploid hybrid speciation. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 346–354.     

Success of Delayed Translocation of Loggerhead Turtle Nests

ABSTRACT Sea turtle embryo mortality in natural nests due to environmental and anthropogenic factors can be very high. To increase hatching success of these endangered species, nest translocation to hatcheries immediately after egg-laying is a common management tool. To test the viability of delayed translocation, we moved 50 loggerhead sea turtle (Caretta caretta) nests to a beach hatchery after various times (0–96 hr) after egg-laying at Boavista Island (Republic of Cabo Verde, western Africa). We transported eggs in a rigid plastic container, being careful to maintain their original vertical orientation. Delayed translocation times of 0 hours, 12 hours, 24 hours, 84 hours, or 96 hours after egg-laying did not have any effect on hatching success, incubation period, or hatchling size and mass. Delayed translocation slightly increased the duration of the translocation process because of extra precautions taken (e.g., maintaining axial orientation, protecting eggs from mechanical shocks). We conclude that delayed nest translocation can be done in a safe and effective way, thereby increasing the efficiency of the whole monitoring program. Finally, delayed translocation, accompanied by an evaluation of fertility, would seem to permit the removal of undeveloped eggs and to facilitate their subsequent exploitation by local communities without affecting turtle nesting success.     

Karyological evolution in Rhaponticum Vaill. (Asteraceae, Cardueae) and related genera

Chromosome counts are reported in 29 populations representing 20 species and one subspecies of the genera Callicephalus (one sp.), Klasea (seven spp.), Myopordon (two spp.), Oligochaeta (one sp.), and Rhaponticum (nine spp., one ssp.). Eleven reports are new, the others supplement limited previous data. New and published cytological data are summarized and evaluated critically in light of current taxonomic treatments and evolutionary hypotheses. Basic chromosome numbers are a valuable source of taxonomic information and relate well to the phylogeny. They are quite conserved in Klasea (only x  = 15), the sister group of the remaining genera, and in the early branching genera of the Rhaponticum group ( x  = 14 for Centaurothamnus and Callicephalus ). However, a more complex pattern of genome evolution is present among the more derived clades, Oligochaeta plus Myopordon ( x  = 12, 14) and the genus Rhaponticum ( x  = 12, 13). The occurrence of x  = 12 in Oligochaeta divaricata and Rhaponticum carthamoides seems to be the result of a recent event of chromosome fusion, as suggested by the fragility of particularly long pairs of chromosomes. The use of chromomycin staining, including an enzymatic digestion step that facilitates spreading and permits a reduction of potential fragmentation, only partially resolves this problem.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 193–201.     

Mazahua ethnobotany and subsistence in the monarch butterfly biosphere reserve, Mexico

This is the first report on Mazahua knowledge and classification of plants and mushrooms and the roles of these resources in the local economy in the Monarch Butterfly Biosphere Reserve, Mexico. A total of 213 useful plant species and 31 species of edible mushrooms were recorded. Fruits ofPrunus serotina, Rubus liebmanii, andCrataegus mexicana were the main wild fruit gathered by people (7.47, 4.40, and 1.82 tons of fruits per year, respectively), whereas their availability in the territory of the village was approximately 302.6, 6.0, and 34.188 tons.Brassica campestris, Rorippa nasturtium-aquaticum, Chenopodium berlandieri, and Amaranthus hybridus were the principal non-cultivated greens consumed by people (4.3, 0.5, 0.7, and 0.9 tons per year, while 23.6, 3.78, traces, and 46.0 tons, respectively, were available). Extraction of medicinal plants is low but gathering ofTernstroemia spp. flowers endangers local populations of these plants. All households of the village used fuelwood (1,767.2 tons per year), mainly of pine and oak species. Strategies for sustainable use of these resources are discussed     

More rapid shift to a benthic niche in larger Gadus morhua juveniles

Trophic use by Atlantic cod Gadus morhua juveniles was examined early and late in the shift from pelagic to benthic habitats. Changes in the proportion of pelagic copepods, estimates of benthic prey indicated by isotope mixing models and stable‐isotope values between sample periods suggested a gradual shift towards a benthic niche. Values of the trophic proxies, however, changed most markedly in the largest juvenile group, suggesting a more rapid trophic niche shift, and in turn competitive advantage, of larger juveniles.     

Competitor avoidance drives within‐host feeding site selection in a passively dispersed herbivore

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