Search results for "Systematics"
showing 10 items of 6702 documents
Lateralized memory storage and crossed inhibition during odor processing by Limax.
2000
After odor conditioning intact Limax maximus and injecting LY into their haemocoel, labeled groups of neurons are found in either the right or left procerebral lobe but never in both procerebral lobes. This suggests that a competitive interaction occurs between right and left odor processing pathways of which the procerebral lobe is a part. We use the nerve discharge in the external peritentacular nerve evoked by applying a puff of conditioned odor to the nose to document crossed inhibition between left and right odor processing pathways. Responses in the external peritentacular nerve evoked by stimulating one superior nose with a conditioned odor are strongly lateralized as responses occur…
What is the function of neuroglobin?
2009
SUMMARY For a long time, haemoglobin and myoglobin had been assumed to represent the only globin types of vertebrates. In 2000, however, we discovered a third globin type by mining the genome sequence data. Based on a preferential expression in the nervous system, this globin is referred to as neuroglobin. Despite nine years of research, its function is still uncertain and a number of hypotheses have been put forward. Neuroglobin enhances cell viability under hypoxia and under various types of oxidative stress in transgenic systems, but does not appear to be strongly upregulated in response to stress. A close phylogenetic relationship with invertebrate nerve globins and its positive correla…
Tetrachromatic color vision in goldfish: evidence from color mixture experiments
1992
Additive color mixture experiments were performed in the goldfish using a behavioral training technique in which the fish had to discriminate between two test fields.
Studies on the laboratory mating habits of the mosquito Culex pipiens
2009
SYNOPSIS The variation in copulatory activity in three strains of Culex pipiens is investigated and the results are discussed in relation to genetic control of mosquito populations.
Honeybee (Apis mellifera) vision can discriminate between and recognise images of human faces.
2005
SUMMARY Recognising individuals using facial cues is an important ability. There is evidence that the mammalian brain may have specialised neural circuitry for face recognition tasks, although some recent work questions these findings. Thus, to understand if recognising human faces does require species-specific neural processing, it is important to know if non-human animals might be able to solve this difficult spatial task. Honeybees (Apis mellifera) were tested to evaluate whether an animal with no evolutionary history for discriminating between humanoid faces may be able to learn this task. Using differential conditioning, individual bees were trained to visit target face stimuli and to …
Origin and evolution of arthropod hemocyanins and related proteins.
2002
Arthropod hemocyanins are large, multimeric, (n x 6) copper-containing proteins that deliver oxygen in the haemolymph of many chelicerate, crustacean, myriapod, and also possibly some insect species. The arthropod hemocyanins belong to a large protein superfamily that also includes the arthropod phenoloxidases, certain crustacean and insect storage proteins (pseudo-hemocyanins and hexamerins), and the insect hexamerin receptors. Here I summarise the present knowledge of the origin, functional adaptations, and evolution of these proteins. Arthropod and mollusc hemocyanins are, if at all, only distantly related. As early as in the arthropod stem line, the hemocyanins emerged from a phenoloxid…
LA SISTEMATICA DEI PHYTOSEIIDAE: CENNI STORICI, SITUAZIONE ATTUALE E PROSPETTIVE DI SVILUPPO
2016
La sistematica della famiglia Phytoseiidae ha una lunga e controversa storia. Tra le cause principali di queste controversie possiamo ricordare le piccole dimensioni di questi acari e le conseguenti difficoltà di individuare caratteri morfologici universalmente validi da adoperare in una classificazione sistematica che rispecchi anche la filogenesi. Viene riportato in seguito un excursus storico della sistematica di questi piccoli predatori focalizzando l’attenzione alle due più importanti teorie di organizzazione dei taxa nell’ambito della famiglia che si sono delineate nel tempo e attualmente vengono adottate dai diversi sistematici. L’autore ha cercato di individuare i punti deboli di en…
Status of two cryptic species, Typhlodromus exhilaratus Ragusa and Typhlodromus phialatus Athias-Henriot (Acari: Phytoseiidae): consequences for taxo…
2006
Typhlodromus phialatus and T. exhilaratus are morphologically close species. Their differentiation is based on the shape of the insemination apparatus and on idiosomal setae length. However, the setae length values are often intermediate between these two species and do not allow accurate identification. Furthermore, the handful of differences in insemination apparatus shape are also questionable as a means of differentiation. Synonymy between these species has thus been questioned. Three experiments were carried out. Idiosomal seta length measurements, molecular tests and cross experiments were conducted for three populations, identified as T. exhilaratus and T. phialatus according to the …
Three new species of phytoseiid mites from Kenya (Mesostigmata: Phytoseiidae)
1978
The following 13 species of predacious mites of the family Phytoseiidae are recorded from various plants in Kenya: Amblyseius albizziae sp. nov., A. kenyae sp. nov., A. natalensis Van der Merwe, A. lokele Pritchard & Baker, A. largoensis (Muma), A. rykei Pritchard & Baker, A. teke Pritchard & Baker, Typholdromus kikuyuensis sp. nov., T. magdalenae Pritchard & Baker, Phytoseius amba Pritchard & Baker, p. ferox Pritchard & Baker, Iphiseius degenerans (Berlese), I. gongylus Pritchard & Baker. The new species and the male of A. natalensis are described.
Formation of melanin-based wing patterns is influenced by condition and immune challenge in Pieris brassicae
2005
According to life-history theory, trade-offs emerge because organisms possess a limited amount of resources that they have to allocate between different bodily functions. Here, we tested whether there is a trade-off between melanin-based immune response and dark melanized wing patterning in the large white butterfly, Pieris brassicae L. (Lepidoptera: Pieridae), by activating the immune system of pupae and measuring the wing pigmentation of freshly emerged adults. In contrast to expectations, we did not find any negative associations between immune challenge and wing patterning. Furthermore, implanted and punctured male pupae tended to have larger and darker forewing tips as adults compared …