Search results for "structures"
showing 10 items of 4815 documents
Blood parasites mediate morph-specific maintenance costs in a colour polymorphic wild bird
2011
Parasites can mediate profound negative effects on host fitness. Colour polymorphism has been suggested to covary genetically with intrinsic physiological properties. Tawny owl colour polymorphism is highly heritable with two main morphs, grey and brown. We show that experimental medication acts to reduce blood parasites and that medicated grey females maintain body mass during breeding, whereas medicated brown females decline in body mass similar to control females of both morphs. We find no effect of medication on general immunoglobulin levels, antigen-specific humoral response or H/L ratio. In the descriptive data, both morphs have similar blood parasite infection rates, but blood parasi…
Do colour morphs of wall lizards express different personalities?
2021
Abstract Colour morphs sometimes have different behavioural strategies which may be maintained by frequency or density dependence mechanisms. We investigated temporal changes in behavioural reaction to a novel environment among colour morphs (yellow, orange, white) of the European wall lizard (Podarcis muralis). Adult males were given two 15 min experimental trials, and their locomotion was highly consistent between the two trials. Boldness, freezing and escape behaviour were less repeatable. Colour morphs differed in their locomotion and freezing behaviour. Boldness was similar among the morphs, whereas escape behaviour was lowest in yellow morph. Consequently, yellow morph males tended to…
First Descriptions of Larva and Pupa of Bagous claudicans Boheman, 1845 (Curculionidae, Bagoinae) and Systematic Position of the Species Based on Mol…
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.
Early exposure to predation risk carries over metamorphosis in two distantly related freshwater insects
2017
1. Predation and competition play a central role in ecological communities, and it is increasingly recognised that animals use early warning cues to reduce the impact of these antagonistic interactions. 2. Strategies to avoid risk can occur during embryo development through plasticity in egg hatching time. This strategy, and its associated costs and carryover effects on adults are little understood in insects. In this study, these are explored in two distantly related freshwater insects: the damselfly Ischnura elegans and the mosquito Aedes albopictus. 3. As predicted, damselfly eggs hatched earlier in response to larval predators cues, a treatment that also affected adult size. Risk cues d…
DNA barcoding the phyllosoma of Scyllarides squammosus (H. Milne Edwards, 1837) (Decapoda: Achelata: Scyllaridae)
2016
Scyllarides has the largest number of species with commercial importance within the Scyllaridae family. As for other achelate lobsters, however, little is known of the unique long-lived planktonic phyllosoma stages of any of these tropical and temperate species. Recently, a large and diverse collection of Scyllaridae phyllosoma, compiled from cruises along the Coral Sea and spanning several years, has been analysed. Molecular evidence from DNA-barcoding and phylogenetic analyses is provided here on the identity of S. squammosus phyllosoma larvae, including stages that were previously undescribed or poorly known. As a consequence, the growth and morphological changes that occur during the mi…
Interspecific comparison of the performance of soaring migrants in relation to morphology, meteorological conditions and migration strategies.
2012
This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Geographical variation in egg mass and egg content in a passerine bird
2011
Reproductive, phenotypic and life-history traits in many animal and plant taxa show geographic variation, indicating spatial variation in selection regimes. Maternal deposition to avian eggs, such as hormones, antibodies and antioxidants, critically affect development of the offspring, with long-lasting effects on the phenotype and fitness. Little is however known about large-scale geographical patterns of variation in maternal deposition to eggs. We studied geographical variation in egg components of a passerine bird, the pied flycatcher (Ficedula hypoleuca), by collecting samples from 16 populations and measuring egg and yolk mass, albumen lysozyme activity, yolk immunoglobulins, yolk and…
Colour variation and alternative reproductive strategies in females of the Common lizard Lacerta vivipara
2007
Within-sex colour variation is a widespread phenomenon in animals that often plays a role in social selection. In males, colour variation is typically associated with the existence of alternative reproductive strategies. Despite ecological conditions theoretically favourable to the emergence of such alternative strategies in females, the social significance of colour variation in females has less commonly been addressed, relative to the attention given to male strategies. In a population of the common lizard, females display three classes of ventral colouration: pale yellow, orange and mixed. These ventral colours are stable through individual's life and maternally heritable. Females of dif…
Eye fluke-induced cataracts in natural fish populations: is there potential for host manipulation?
2010
SUMMARYManipulation of host phenotype (e.g. behaviour, appearance) is suggested to be a common strategy to enhance transmission in trophically transmitted parasites. However, in many systems, evidence of manipulation comes exclusively from laboratory studies and its occurrence in natural host populations is poorly understood. Here, we examined the potential for host manipulation by Diplostomum eye flukes indirectly by quantifying the physiological effects of parasites on fish. Earlier laboratory studies have shown that Diplostomum infection predisposes fish to predation by birds (definitive hosts of the parasites) by reducing fish vision through cataract formation. However, occurrence of ca…
Comparative analysis of the proximate and elemental composition of the blue crab Callinectes sapidus, the warty crab Eriphia verrucosa, and the edibl…
2016
AbstractThe proximate composition and element contents of claw muscle tissue of Atlantic blue crabs (Callinectes sapidus) were compared with the native warty crab (Eriphia verrucosa) and the commercially edible crab (Cancer pagurus). The scope of the analysis was to profile the chemical characteristics and nutritive value of the three crab species. Elemental fingerprints showed significant inter-specific differences, whereas non-significant variations in the moisture and ash contents were observed. In the blue crab, protein content was significantly lower than in the other two species, while its carbon content resulted lower than that characterizing only the warty crab. Among micro-elements…