Search results for "MORPHOLOGY"
showing 10 items of 1425 documents
Establishing Laboratory Cultures and Performing Ecological and Evolutionary Experiments with the Emerging Model Species Chironomus Riparius
2018
Chironomus riparius is a well-established model organism in various fields such as ecotoxicology and ecology, and therefore environmental preferences, ecological interactions and metabolic traits are well-studied. With the recent publication of a high-quality draft genome, as well as different population genetic parameters such as mutation and recombination rate, the species can be used as an alternative to the Drosophila models in experimental population genomics or molecular ecology. To facilitate access to this promising experimental model species for a wider range of researchers, we describe experimental methods to first create and sustain long term cultures of C. riparius and then use …
First Descriptions of Larva and Pupa of
2019
In this paper, the mature larva and pupa of Bagous claudicans are described and illustrated for the first time. Measurements of younger larval instars are also given. The biology of the species is discussed in association with larval morphology and feeding habits. Overall larval and pupal morphological characters of the genus Bagous are presented. Confirmation of the larva identification as Bagous claudicans species was conducted by cytochrome oxidase I (COI) sequencing. DNA barcoding was useful for specimen identification of larval stages. The systematic position of the species within the Bagous collignensis-group, based on morphological and molecular results, is also discussed.
Passive sinking into the snow as possible survival strategy during the off-host stage in an insect ectoparasite
2015
Abiotic and biotic factors determine success or failure of individual organisms, populations and species. The early life stages are often the most vulnerable to heavy mortality due to environmental conditions. The deer ked (Lipoptena cervi Linnaeus, 1758) is an invasive insect ectoparasite of cervids that spends an important period of the life cycle outside host as immobile pupa. During winter, dark-coloured pupae drop off the host onto the snow, where they are exposed to environmental temperature variation and predation as long as the new snowfall provides shelter against these mortality factors. The other possible option is to passively sink into the snow, which is aided by morphology of …
1400 years of man-environment interactions and soil evolution in the Saint-Mont mountain (Remiremont, Vosges)
2021
International audience; The SolHoM(a) project aims at determining the degree of landscape anthropisation in the Fossard massif (Remiremont, Vosges, France) by estimating the impact of past human occupations on current soils. Nowadays, a forest covers this relatively inhospitable mountain (hard climate, steep slopes, acid soils ...), but some remains suggest human presence for at least 1400 years.The Saint-Mont is a variscan orogenic granitic summit (height 672m) with valuable preserved archaeological relics, located south of the Fossard. At the top was founded the monasterium Habendum (from the 7th century to the French Revolution), which potentially comes after a late-antic castrum.Further…
Food web structure of an Arctic lake (Pulmankijärvi, northern Finland) studied by stable isotope analyses
2007
Revision of asterolepidoid antiarch remains from the Ogre Formation (Upper Devonian) of Latvia
2020
The Frasnian (Upper Devonian) antiarch Walterilepis speciosa was first described in 1933 (as Taeniolepis) on the basis of a single specimen. The newly collected material has allowed the head to be described in a more detail, especially the nuchal and paranuchal plates. Other newly described elements include bones of the pectoral appendages and trunk armour, demonstrating a rather high and short trunk armour. The shape and proportions of the head and trunk armour suggest the attribution of Walterilepis to the family Pterichthyodidae; it is most probably closely related to Lepadolepis from the Late Frasnian of Germany. Whilst W. speciosa is endemic to the Latvian part of the Baltic Devonian B…
A quantitative assessment of intraspecific morphological variation in Gahagan bifaces from the southern Caddo area and central Texas
2019
This investigation aggregates intact or reconstructed Gahagan bifaces from the southern Caddo area and central Texas to test the hypothesis that Gahagan biface morphology differs between the regions. The Gahagan bifaces (n = 102) were scanned, then analysed using a novel landmarking protocol and the tools of geometric morphometrics. Results provide a preview of the significant differences in Gahagan biface morphology expressed between the southern Caddo area and central Texas regions. The size discrepancy represents an inversion of current theoretical constructs that posit a decrease in tool size thought to articulate with an increase in distance from the raw material source. It is posited …
New Polylactic Acid Composites Reinforced with Artichoke Fibers
2015
In this work, artichoke fibers were used for the first time to prepare poly(lactic acid) (PLA)-based biocomposites. In particular, two PLA/artichoke composites with the same fiber loading (10% w/w) were prepared by the film-stacking method: the first one (UNID) reinforced with unidirectional long artichoke fibers, the second one (RANDOM) reinforced by randomly-oriented long artichoke fibers. Both composites were mechanically characterized in tensile mode by quasi-static and dynamic mechanical tests. The morphology of the fracture surfaces was analyzed through scanning electron microscopy (SEM). Moreover, a theoretical model, i.e., Hill's method, was used to fit the experimental Young's modu…
The indigenous germplasm of chestnut (Castanea sativa Mill.) in the Etna area: Ecophysiological aspects and morphological traits of the fruits
2006
In Sicily, chestnut ( Castanea sativa Mill.) is present at altitudes that run from 300 to 1600 m asi and, due to the extreme variability of the environmental conditions, a large autochthonous germplasm has been dif- ferentiated. On the island, starting back as far as ancient times, chestnut was an important crop for rural com- munities but, after the Second World War, the tendency of the rural population to move to the capital cities and because of Cryphonectria parasitica attacks, chestnut plantings reduced dramatically. Recently, an investigation has commenced in the Etna area to collect the residual genetic resources of chestnut. Although many of the che- stnut genotypes found on the slo…