Search results for "Isopod"
showing 10 items of 34 documents
Medium-term dynamics of element concentrations in a sparid fish and its isopod parasite after the Prestige oil-spill: Shifting baselines?
2019
Historically, the European Atlantic is probably the most important oil-spill hotspot worldwide. One of the most recent accidents occurred in 2002 when the oil-tanker Prestige sank over the Galician Bank causing two major oil-spills followed by several small leaks until March 2003. This resulted in contamination of virtually all types of marine habitat. Considering that parasites have proved to be good effect and accumulation bioindicators, the present study addresses the medium-term changes in trace element content after the Prestige oil-spill in a model host-parasite system, the bogue, Boops boops (Sparidae) and the isopod Ceratothoa oestroides. To our knowledge, this study is the first to…
Soil macroarthropod communities in planted birch stands in comparison with natural forests in central Finland
2002
The aim of the study was to compare the soil macroarthropod communities in anthropogenous birch stands of different origin with each other and with natural forests at the same latitude in Finland. A total of nine forest sites was investigated: three birch stands (Betula pendula) planted ca. 30 years prior to the study after clear-cutting of spruce stands (“Birch after Spruce”, BS), three birch stands planted ca. 30 years earlier on arable soil that had been under normal cultivation until reforestation (“Birch after Field”, BF), and three “Natural Deciduous” (D) forests. These were sampled three times in 1998, animals were extracted with large Tullgren funnels, counted per square metre, and …
Evidence for a new feminizing Wolbachia strain in the isopod Armadillidium vulgare: evolutionary implications.
2004
Wolbachia are intracellular maternally inherited alpha-Proteobacteria infecting a wide range of arthropods. In the common pill bug Armadillidium vulgare, the known Wolbachia strain is responsible for feminization of genetic males. We have investigated Wolbachia diversity in 20 populations of A. vulgare from west and east Europe, north Africa and north America. A new Wolbachia strain (wVulM) was identified through the variability of the wsp gene, distantly related to that previously known (wVulC) in this host species. No individual with multiple infections was detected. Inoculation experiments indicated that the new wVulM bacterial strain also induces feminization in A. vulgare. However, the…
Bacillus species in the intestine of termites and other soil invertebrates
2006
Soil invertebrates harbour a complex microbial community in their intestinal system. The total number of microbes in the hindgut of soil invertebrates can reach a titre of 10(11) ml(-1). The gut microbes play an indispensable role in the digestion of food and are of ecological importance in the global carbon cycle. The gut microbiota can include a variety of micro-organisms from the three domains Bacteria, Archaea and Eucarya. The bacterial groups from the intestinal systems are mainly affiliated to the proteobacteria, the gram-positive groups Firmicutes and Actinobacteria, the Bacteroides/Flavobacterium branch and the spirochetes. The Archaea are represented by methanogens. The eukaryotic …
Costs of parasite resistance for female survival and parental care in a freshwater isopod
2006
Parasite resistance is expected to be costly because activation and maintenance of immune system requires energy that will not be available for other fitness related functions. Here, we experimentally exposed gravid female isopods from two lake populations to trophically transmitted acanthocephalan parasite. Successful establishment of the parasite requires penetration to body cavity; therefore, it is likely to induce an immune response. Resistant females from a lake where the parasite occurs as well as from a lake without the parasite experienced higher mortality than susceptible or control females. Parasite exposure reduced the offspring size at birth in both susceptible, but especially, …
Heading which way? Y-maze chemical assays: not all crustaceans are alike
2015
In a world full of chemicals, many crustaceans rely on elaborate olfactory systems to guide behaviors related to finding food or to assess the presence of conspecifics and predators. We analyzed the responses of the isopod Saduria entomon to a range of stimuli by which the animal is likely to encounter in its natural habitat using a Y-maze bioassay. In order to document the efficiency of the experimental design, the same bioassay was used to test the behavior of the crayfish Procambarus fallax whose ability to track odors is well documented. The crayfish performed well in the Y-maze and were able to locate the source of a food-related odor with high fidelity. The isopod S. entomon reacted i…
Nesting of the Spotless Starling, Sturnus unicolor, on the island of Favignana (Aegadian Islands, Sicily)
2021
The presence of the Spotless Starling in Sicily was reported for the first time at the beginning of the XIX century, although the first nests for the province of Trapani are reported almost at the end of the XX century. As a breeder, the Spotless Starling remained absent from all the circumsicilian islands until the first report for the island of Pantelleria, in 2012. In 2020, the nest of Spotless Starling was observed on the island of Favignana, within a hole on an antenna. The couple fed the chicks with Ligia italica crustacean isopod of the family Ligiidae. The nesting on the island of Favignana confirms the continuous expansion of the species in Sicily
Multi-infections of feminizing Wolbachia strains in natural populations of the terrestrial isopod Armadillidium vulgare.
2013
7 pages; International audience; Maternally inherited Wolbachia (α-Proteobacteria) are widespread parasitic reproductive manipulators. A growing number of studies have described the presence of different Wolbachia strains within a same host. To date, no naturally occurring multiple infections have been recorded in terrestrial isopods. This is true for Armadillidium vulgare which is known to harbor non simultaneously three Wolbachia strains. Traditionally, such Wolbachia are detected by PCR amplification of the wsp gene and strains are characterized by sequencing. The presence of nucleotide deletions or insertions within the wsp gene, among these three different strains, provides the opportu…
Sexual selection, antennae length and the mating advantage of large males in Asellus aquaticus
2003
In crustacean species with precopulatory mate-guarding, sexual size dimorphism has most often been regarded as the consequence of a large male advantage in contest competition for access to females. However, large body size in males may also be favoured indirectly through scramble competition. This might partly be the case if the actual target of selection is a morphological character, closely correlated with body size, involved in the detection of receptive females. We studied sexual selection on body size and antennae length in natural populations of Asellus aquaticus, an isopod species with precopulatory mate guarding. In this species, males are larger than females and male pairing succe…
Variable male potential rate of reproduction: high male mating capacity as an adaptation to parasite–induced excess of females?
2003
Numerous animals are known to harbour intracytoplasmic symbionts that gain transmission to a new host generation via female eggs and not male sperm. Bacteria of the genus Wolbachia are a typical example. They infect a large range of arthropod species and manipulate host reproduction in several ways. In terrestrial isopods (woodlice), Wolbachia are responsible for converting males into females (feminization (F)) in some species, or for infertility in certain host crosses in other species (cytoplasmic incompatibility (CI)). Wolbachia with the F phenotype impose a strong excess of females on their host populations, while Wolbachia expressing CI do not. Here, we test the possibility that male m…