Search results for "larva"
showing 10 items of 632 documents
First Data on the Helminth Community of the Smallest Living Mammal on Earth, the Etruscan Pygmy Shrew, Suncus etruscus (Savi, 1822) (Eulipotyphla: So…
2021
Suncus etruscus is the smallest living mammal on Earth by mass. Most adults weigh 1.8–3 g with a body length of 35–48 mm. Catching it in small mammal traps in nature is extremely difficult due to its minute size, and therefore special trapping methods must be used. We had the unique opportunity of studying, for the first time, the helminth parasites of 166 individuals of S. etruscus, part of the largest collection in the world, which belonged to the French scientist Dr Roger Fons (1942–2016). A total of 150 individuals were captured in the Banyuls-Cerbère area (France) and 16 in the island of Corsica (France). We found seven helminth species, specifically, the cestodes Joyeuxiella pasqualei…
Microbiome-assisted carrion preservation aids larval development in a burying beetle
2018
Significance Ephemeral diets such as carrion are high-quality resources that are susceptible to microbial spoilage. Carrion-feeding insects that breed on decaying carcasses must overcome challenges arising from competing microbes. Here we report that a carrion-feeding burying beetle preserves carcasses by regulating its microbial growth, resulting in changes in its biochemical properties including the reduction of toxic polyamines associated with putrefaction and nutrient loss. The beetle’s microbial symbionts form a biofilm-like matrix on carcasses, which is important for optimal larval development. The beetles and their microbiome thus coordinate a specialized adaptive strategy of carrion…
Burying beetles regulate the microbiome of carcasses and use it to transmit a core microbiota to their offspring
2017
Necrophagous beetles utilize carrion, a highly nutritious resource that is susceptible to intense microbial competition, by treating it with antimicrobial anal and oral secretions. However, how this regulates the carcass microbiota remains unclear. Here, we show that carcasses prepared by the burying beetle Nicrophorus vespilloides undergo significant changes in their microbial communities subsequent to their burial and ‘preparation’. Prepared carcasses hosted a microbial community that was more similar to that of beetles’ anal and oral secretions than to the native carcass community or the surrounding soil, indicating that the beetles regulated the carcass microbiota. A core microbial comm…
Amino acid composition in eyes from zebrafish (Danio rerio) and sardine (Sardina pilchardus) at the larval stage
2016
A comparative study was performed to identify differences in the amino acid composition of the eyes from zebrafish (Danio rerio) and sardine (Sardina pilchardus) larvae and their link to the environmental adaption of the species. Amino acids in the acidic hydrolysates of eyes from 11 zebrafish and 12 sardine were determined with the use of high-performance liquid chromatography involving precolumn derivatization with ortho-phthalaldehyde. Differences in the content of most amino acids were detected between zebrafish and sardine. These amino acids were aspartate, glutamate, serine, glycine, threonine, arginine, methionine, valine, phenylalanine, isoleucine, leucine and lysine. Of particular …
Pre-imaginal conditioning alters adult sex pheromone response in Drosophila
2018
https://peerj.com/articles/5585/#supplemental-information; International audience; Pheromones are chemical signals that induce innate responses in individuals of the same species that may vary with physiological and developmental state. In Drosophila melanogaster, the most intensively studied pheromone is 11-cis-vaccenyl acetate (cVA), which is synthezised in the male ejaculatory bulb and is transferred to the female during copulation. Among other effects, cVA inhibits male courtship of mated females. We found that male courtship inhibition depends on the amount of cVA and this effect is reduced in male flies derived from eggs covered with low to zero levels of cVA. This effect is not obser…
Trematode cercariae as prey for zooplankton: effect on fitness traits of predators.
2019
AbstractRemoval of parasite free-living stages by predators has previously been suggested an important factor controlling parasite transmission in aquatic habitats. Experimental studies of zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous in shallow waters, are suitable prey for syntopic zooplankters. Feeding rates and survival of freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) and rotifers Asplanchna spp., fed with cercariae of Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term e…
The Severity of Acute Stress Is Represented by Increased Synchronous Activity and Recruitment of Hypothalamic CRH Neurons
2016
The hypothalamo-pituitary-adrenocortical (HPA) axis regulates stress physiology and behavior. To achieve an optimally tuned adaptive response, it is critical that the magnitude of the stress response matches the severity of the threat. Corticotropin-releasing hormone (CRH) released from the paraventricular nucleus of the hypothalamus is a major regulator of the HPA axis. However, how CRH-producing neurons in an intact animal respond to different stressor intensities is currently not known. Using two-photon calcium imaging on intact larval zebrafish, we recorded the activity of CRH cells, while the larvae were exposed to stressors of varying intensity. By combining behavioral and physiologic…
Tolerance of whitefish (Coregonus lavaretus) early life stages to manganese sulfate is affected by the parents
2016
European whitefish (Coregonus lavaretus) embryos and larvae were exposed to 6 different manganese sulfate (MnSO4) concentrations from fertilization to the 3-d-old larvae. The fertilization success, offspring survival, larval growth, yolk consumption, embryonic and larval Mn tissue concentrations and transcript levels of detoxification-related genes were measured in the long-term incubation. Full factorial breeding design (4 females x 2 males) enabled examining the significance of both female and male effects, and female-male interactions in conjunction with the MnSO4 exposure on the observed endpoints. The MnSO4 exposure reduced the survival of the whitefish early life stages. Also the offs…
The Amino Acid Transporter JhI-21 Coevolves with Glutamate Receptors, Impacts NMJ Physiology, and Influences Locomotor Activity in Drosophila Larvae
2015
AbstractChanges in synaptic physiology underlie neuronal network plasticity and behavioral phenomena, which are adjusted during development. The Drosophila larval glutamatergic neuromuscular junction (NMJ) represents a powerful synaptic model to investigate factors impacting these processes. Amino acids such as glutamate have been shown to regulate Drosophila NMJ physiology by modulating the clustering of postsynaptic glutamate receptors and thereby regulating the strength of signal transmission from the motor neuron to the muscle cell. To identify amino acid transporters impacting glutmatergic signal transmission, we used Evolutionary Rate Covariation (ERC), a recently developed bioinforma…
Functional insights into the infective larval stage of Anisakis simplex s.s., Anisakis pegreffii and their hybrids based on gene expression patterns
2018
[Background]: Anisakis simplex sensu stricto and Anisakis pegreffii are sibling species of nematodes parasitic on marine mammals. Zoonotic human infection with third stage infective larvae causes anisakiasis, a debilitating and potentially fatal disease. These 2 species show evidence of hybridisation in geographical areas where they are sympatric. How the species and their hybrids differ is still poorly understood. [Results]: Third stage larvae of Anisakis simplex s.s., Anisakis pegreffii and hybrids were sampled from Merluccius merluccius (Teleosti) hosts captured in waters of the FAO 27 geographical area. Specimens of each species and hybrids were distinguished with a diagnostic genetic m…