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This study was designed to assess the impact of the mixture of cadmium (Cd) and zinc (Zn) on the bioaccumulation and the ultrastructural changes in the hepatopancreas of Porcellio laevis (Latreille, 1804) after 4 weeks of exposure to contaminated Quercus leaves under laboratory conditions. For each metal, four concentrations were used with four replicates for each concentration. Metal concentrations in the hepatopancreas and the rest of the body were determined using atomic absorption spectrometry. From the first week until the end of the experiment, a weight gain in P. laevis was observed particularly between the first and the end of exposure from 93.3 ± 18.22 mg fw to 105.22 ± 16.16 mg fw and from 106.4 ± 22.67 mg fw to 125.9 ± 23.9 mg fw for Mix1 and Mix4, respectively. Additionally, the determined metal trace elements (MTE) concentrations in the hepatopancreas were considerably higher compared to those in the rest of the body and seem to be dose-dependent. Using transmission electron microscopy (TEM), some alterations were highlighted in the hepatopancreas. The main observed alterations were (a) the destruction of the microvilli border in a considerable portion of cells, (b) the increase of the lipid droplets with different shapes and sizes, (c) the increase in the number of the mitochondria, and (d) the appearance of TE in the form of B-type granules. The obtained results confirmed the ability of P. laevis to deal with high amounts of MTE, suggesting its possible use in future soil's biomonitoring programs.

Effects of trace elements on the hepatopancreas ultrastructure and on the locomotor activity rhythm were investigated in the amphipod talitrid Orchestia gammarellus collected from Bizerte lagoon banks situated in the north of Tunisia. Animals were exposed to a series of contaminated soil with different concentrations of cadmium and zinc. The locomotor activity rhythm was studied under constant darkness. Histopathological analysis showed that the trace elements, especially the Cd, induced significant changes in the morphology and in the ultrastructural organization of hepatopancreatic cells. The significant alterations obtained were dose dependent. Concerning the behavioral response, results revealed the presence of two components whatever the experimental conditions. In addition, a great inter-individual variability of the locomotor rhythm was observed. Patterns were in majority bimodal for the control individuals and became unimodal and multimodal when exposed under Cd and Zn, respectively. Furthermore, ultradian and circadian periods were determined. The circadian period lengthened after Zn exposure. In addition, the locomotor activity rhythm was more stable for control individuals. However, those exposed to Cd were less active.

To estimate trace element bioaccumulation in Armadillo officinalis, specimens were collected then exposed to contaminated sediments with copper and zinc for three weeks.

The hepatopancreas of crustacean species has been recognized as an important target organ for studying the toxic effects of trace metals (TM). This dynamic organ, with its capability of detoxifying trace metals, often indicates distinct pathological disturbances. This study dealt with the evaluation of the histological alterations in the hepatopancreas of the supralittoral amphipod Orchestia montagui Audouin, 1826 exposed to a mixture of copper and zinc. After exposure, the hepatopancreas was dissected and its ultrastructure was observed using transmission electron microscopy. The obtained results showed that the body mass differed from the control organisms depending on the nominal metal concentration to which they were exposed. The hepatopancreas of unexposed and exposed animals were compared for the detection of histological changes. Significant dose-dependent alterations were noted in all the treatment groups. Among these histological changes of the hepatopancreas in O. montagui, we noted the loss of cell structure, especially cell remoteness and border lyses, a reduction in the nuclear volume, an increase in cytoplasm density with trace metals in both nucleus and vacuoles, a disorganization and destruction of microvilli and a condensation of the majority of cell organelles, and mitochondria swelling. Through this study, O. montagui could be a good indicator providing measurable responses. It could be an attractive candidate for the biochemical study of TM toxicity in coastal ecosystems.

This study was conducted to compare metals bioaccumulation in the Talitrid O. mediterranea collected from the banks of Bizerte lagoon. Individuals were exposed to a series of contaminated soil with...

Terrestrial isopods have adapted to land life by diverse morphological, physiological and behavioral changes. Isopod species exhibit a large variety of preferences ranging from moist to dry habitats. Isopod cuticle is an interesting model for studying adaptations to terrestrial life. The cuticle consists of a hierarchically organized material which provides protection and sites for muscle attachment. The present paper aimed to investigate the structure of the cuticle in three isopod species in order to relate some peculiar features to an adaptive process to environmental constraints. Results showed that general thickness of Ligia italica cuticle was quite similar to that observed in Porcellio lamellatus. Nevertheless, this cuticle was half as thick as in Porcellio laevis. Although the positive relationship found between total body lengths and the total thickness of the cuticle, the exocuticle did not show any differences between the three species. However, it is the development of a thicker endocuticle in P. laevis which make its total cuticle thickness more important.

Environmental DNA (eDNA) is a powerful method for assessing the presence and distribution of invasive aquatic species. We used this tool to detect and monitor several invasive crayfishes Procambarus clarkii, Orconectes limosus and Pacifastacus leniusculus present in, or likely to invade, the ponds of the Brenne Regional Natural Park. A previous study showed that the eDNA method was not very efficient in detecting P. clarkii. In the present study, we explored new improvements in the detection of invasive crayfish. We designed specific primers for each crayfish species, and set up an experimental mesocosm approach to confirm the specificity of the primers and the sampling protocol. We analysed samples taken from ponds in 2014 and 2015. We compared two qPCR protocols involving either SybrGreen or TaqMan assays. Using these same primers, we were able to detect crayfish eDNA with both assays during the mesocosm experiment. However, crayfish from field samples could only be detected by performing qPCR with a SybrGreen assay. We successfully monitored the presence of three invasive species of crayfish using eDNA. This method is a powerful tool for establishing the presence or absence of invasive species in various freshwater environments.

In Tunisia, while wetlands are considered as remarkable habitats for their faunal and floral diversity, few studies on the biogeography and the diversity of terrestrial isopods were performed. To fill this gap, we carried out a field study in the supralittoral zone of 146 Tunisian wetlands belonging to eight types (lagoon, river, lake, sebkha, dam, hill reservoir, beach and chott) and to five bioclimatic zones (humid, subhumid, semi-arid, arid and Saharan). Field work was carried out in spring 2010. Terrestrial isopods were collected in the morning by hand search each time with the same sampling effort. During the study, 22 species of terrestrial isopods belonging to nine families were collected. Porcellio variabilis, Porcellio laevis, Chaetophiloscia elongata and Armadillidium pelagicum are the most common species identified. From the northern to the southern regions, a gradual decrease in species richness has been shown. The identified species belonged to different biogeographical categories: Mediterranean, Mediterranean-Atlantic, North Africa with circum-Sicilian islands, semi-arid and Saharan species. Some of these species are endemic to Tunisia (Porcellio dominici) or to North Africa (Armadillidium sulcatum, Armadillidium tunisiense, Porcellio marginenotatus and P. variabilis). Terrestrial isopod species differ according to wetland type and bioclimatic zone.

The hepatopancreas of crustaceans species has been recognized as an essential target organ to assess trace elements' effects. Due to its dynamic and capability of detoxifying trace metal, this organ often indicates distinct pathological disturbances. In the present work, we intend to evaluate the bioaccumulation of trace metal in three Orchestia species (Orchestia montagui, Orchestia gammarellus, and Orchestia mediterranea) living in symmetry in the banks of Bizerte lagoon (37°13'8″N 09°55'1″E) after their exposure during 14 days to a mixture of copper and zinc, and to highlight the effect of these metals on their hepatopancreas ultrastructure using transmission electron microscopy. At the end of the experiment, results showed that the mortality and the body mass varied according to the used nominal concentrations. Significant alterations were noted in all the treatment groups. The degree of these alterations depends on the used concentration, and they are represented especially by the cells remoteness and the border lyses, the reduction of the nuclear volume, the increase in the cytoplasm density with the presence of trace metal in the nucleus as well as in the vacuole, the disorganization and the destruction of microvilli, the condensation of the majority of cellular organelles and mitochondria swelling. Through this study, Orchestia genus could be an attractive candidate for the biochemical study of trace metal toxicity in Tunisian wetlands.

This study was conducted to compare metals bioaccumulation in the terrestrial isopod Armadillidium granulatum collected from Ghar El Melh lagoon. We focused on recognizing the effects of trace elements on hepatopancreas functional role. To this end, isopod specimens were exposed for 3 weeks to sediments contaminated with cadmium, copper, zinc, mercury, and nickel. Three concentrations were used in duplicate for each experimental condition. At the end of the experiment, metal body burdens were determined using flame atomic absorption spectrometry. Results of the bioaccumulation factor (BAF) showed that the species A. granulatum was classified as a Cu macroconcentrator (BAF > 2) and a Zn deconcentrator (BAF < 2). Dose dependent morphological and histological changes were observed in the hepatopancreas cells using transmission electron microscopy. The predominant features were: microvillus border disruption, condensation of the cytoplasm with increasing endoplasmic reticulum, mitochondria, lysosomes and granules that accumulated metals in B and S cells. The number of lipid droplets decreased especially after Cd, Zn, Hg, and Ni treatments. This study demonstrated that the terrestrial isopod A. gramulatum could be a good indicator of soil metal contamination.

To estimate trace element bioaccumulation in Armadillo officinalis, specimens were collected from Ghar El Melh lagoon then exposed for 3 weeks in contaminated sediments with copper, zinc, and cadmium. From the first week until the end of the experiment, a decrease in A. officinalis growth related to the increase of Cd concentration in the sediment was recorded. However, a mass gain was highlighted under Cu and Zn exposures. At the end of experiment, body metal concentrations were measured using flame atomic emission spectrometry. Results of the bioaccumulation factor showed that the species could be considered as a macroconcentrator of copper (BAF > 2) and a deconcentrator of zinc (BAF

The ultrastructural changes on the hepatopancreas of Porcellio laevis individuals were investigated after their exposure to a mixture of cadmium (Cd) and zinc (Zn) during four weeks. At the end of the experiment, trace element (TE) concentrations were determined using atomic absorption spectrometry (AAS). The growth of individuals was calculated and compared among the treatments. From the first week until the end of the experiment, a weight gain was observed in P. laevis individuals. Additionally, the TE concentrations in the hepatopancreas and in the rest of the body were considerable and seem to be dose dependent. Moreover, our results confirmed the role of the hepatopancreas as the main storage organ. Thus, the conducted transmission electron microscopy highlighted remarkable alterations on the hepatopancreas cells resulting from the Cd and Zn bioaccumulation. The displayed alterations are principally the disorganization of the S- and B-cells leading to a destruction of the microvilli border, an increase of the lipid droplets and mitochondria as well as the appearance of trace elements in the form of B-type granules. Based on the obtained results herein, we can conclude that Porcellio laevis might be a good candidate in the prevention of TE pollution in the terrestrial ecosystems.

1. Groundwater ecosystems represent the greatest proportion of unfrozen freshwa- ter on Earth and harbour high numbers of rare taxa with restricted distributions. Stygofaunal abundance, species richness, and ecology play essential roles in groundwater ecosystem services and functioning, as well as providing an impor- tant contribution to global biodiversity. However, as global depletion and contam- ination of groundwater pose serious and often irreversible threats to stygofauna, more information is urgently needed about the ecology of rare groundwater spe- cies to guide effective strategies for their conservation or restoration. 2. In this study, analyses of carbon and nitrogen stable isotopes were used to com- pare and evaluate trophic niches and diets of a vulnerable stygobiont isopod, Gallasellus heilyi living in sympatry in French groundwater ecosystems with the isopod Caecosphaeroma burgundum and the amphipod Niphargus ladmiraulti. 3. Stable isotope results showed trophic niche partitioning among the three sty- gobiont species and indicated that G. heilyi and C. burgundum occupy the role of primary consumers and N. ladmiraulti that of predator. Moreover, although G. heilyi and C. burgundum were shown to rely on the same food sources, indicat- ing similar diets, and their trophic niches did not overlap, suggesting trophic specialization. 4. The results suggest that detritus (i.e. decaying organic material) is an important food source for G. heilyi, and its availability could determine the survival of this endangered species. As a practical conservation measure for G. heilyi and the whole stygofauna community, we suggest reconnecting surface and subterranean ecosystems, as they probably were before natural sinks and many wells were filled up or closed. Funding information: Agence de l’Eau Adour-Garonne; Centre National de la Recherche Scientifique; DREAL Nouvelle-Aquitaine; Estonian Ministry of Education and Research, Grant/Award Number: IUT 21-2; Estonian Research Council, Mobilitas Pluss, Grant/Award Number: MOBJD29; Foundation LISEA Biodiversité; Regional Council of Nouvelle-Aquitaine; University of Poitiers. Funding information: Agence de l’Eau Adour-Garonne; Centre National de la Recherche Scientifique; DREAL Nouvelle-Aquitaine; Estonian Ministry of Education and Research, Grant/Award Number: IUT 21-2; Estonian Research Council, Mobilitas Pluss, Grant/Award Number: MOBJD29; Foundation LISEA Biodiversité; Regional Council of Nouvelle-Aquitaine; University of Poitiers.

Terrestrial isopods (Oniscidea) are crustaceans whose ancestors have left the water to conquer land even in arid regions where Hemilepistus reaumurii is living. This species is the only terrestrial isopod conducting a real sub-social life as a monogamous semelparous species forming families. The chemical signature of five family units from this population was investigated by gas chromatography. Results showed highly significant differences among the family units according to: (i) the cuticular chemical profiles which confirm that the cuticle is one of the most important organs involved in family chemical signature and recognition; (ii) the cuticular chemical distances and (iii) the faeces chemical profiles which suggest that these droppings help individuals of the same family to find their burrows and deter intruders. Moreover no significant correlation was shown between faeces chemical distance and the distance between burrows from where the family units were collected.

To evaluate the influence of wetland types on the distribution of terrestrial isopods, species richness, relative abundance and diversity indices were studied in the supralittoral zone of 95 wetlands in the north-western of Tunisian dorsal, belonging to six types: lagoon, hill reservoir, river, dam, lake and sebkha. We tested the following hypothesis: (i) is isopod diversity influenced by wetland types? (ii) is isopod diversity influenced by bioclimatic zones? and (iii) what are the environmental factors influencing isopod distribution? A total of 3255 individuals belonging to twenty species of terrestrial isopods were captured. Species richness differs significantly between wetland types. A highly significant positive relationship between species richness and both humidity and altitudinal gradient was described. The dendrogram of similarities showed a divergence of the lagoons compared to the remaining wetland types.

This study deals with the evaluation of trace element bioaccumulation and histological alterations in the hepatopancreas of the supralittoral amphipod Orchestia montagui Audouin, 1826 due to the exposure to cadmium, copper, and zinc. Orchestia montagui individuals were maintained during 14 days in soils contaminated with different trace elements namely cadmium, copper, and zinc; a control was also prepared. Our results show that the mortality and the body mass vary according to the metal and the nominal concentration used. In general, the mortality increases from the seventh day. However, the body mass shows a decrease with cadmium exposure and an increase with copper and zinc exposures. Furthermore, the concentration factor highlights that this species is considered a macroconcentrator for copper and zinc. The hepatopancreas of unexposed and exposed animals were compared to detect histological changes. Our results show significant alterations in the hepatopancreas of the exposed animals after the experiment. The degree of these alterations was found to be dose-dependent. Among the histological changes in the hepatopancreas in O. montagui, a loss of cell structure was noted, especially cell remoteness and border lyses, the reduction of nuclear volume, an increase in the cytoplasm density with the presence of trace element deposits in both the nucleus and vacuoles, a disorganization and destruction of microvilli, and a condensation of the majority of cell organelles and mitochondria swelling. Through this study, we have confirmed that O. montagui can be a relevant model to assess trace metal element pollution in Tunisian coastal lagoons with the aim of using it in future biomonitoring programs.

Procambarus clarkii is a widespread invasive species and its biological traits have often been used to explain its successful colonization of new areas. However, studies on the genetic features of invasive populations are still scarce, and the use of molecular markers could bring new insights about biological invasions. After being introduced in Spain in 1973, P. clarkii was introduced in France (≈1976) and nowadays is widespread in its territory (61 departments) in wetlands which provide good conditions for a successful colonization. Here we ask whether the genetic diversity of invasive populations could help to understand the evolutionary history of its invasion. To investigate this issue, 227 individuals of P. clarkii from 27 French populations and 10 departments were collected, and a 553 bp COI fragment was amplified and sequenced using universal primers. For the analysis of genetic parameters, nucleotide diversity (π), and haplotype diversity (Hd), the populations were organized into four major groups. The nucleotide diversities (π) were 0.000154, 0.00119, 0.00118, and 0.00123 for group 1, 2, 3, and 4, respectively. The genetic diversity of French populations (Hd = 0.350; π = 0.00123) was lower than the native populations (Hd = 0.982; π = 0.00736). Nine haplotypes were found (H1–H9) in 230 sequences. Haplotype diversity (Hd) was 0.444, 0.239, 0.330, and 0.350 for groups 1, 2, 3, and 4, respectively. The haplotype network showed very similar haplotypes, differing by few mutational steps and showing some complex relationships. Three haplotypes related to the species’ native region were found (H1, H2, and H3). Each of these haplotypes was also related to biogeographical regions. The most frequent haplotype (H2) was widespread throughout 10 departments. The other six haplotypes (H4, H5, H6, H7, H8, and H9) were not found in the native region but, in some cases, shared some French populations. Translocation by humans is the most plausible explanation of the observed haplotype relationships. We suggest that genetic information should play a larger role in the development of policies to manage invasive species.

Mate choice is an important process in sexual selection and usually prevents inbreeding depression in populations. In the terrestrial isopod Armadillidium vulgare, the close physical proximity between individuals may increase the risk of reproducing with siblings. Moreover, individuals of this species can be infected with the feminizing bacteria of Wolbachia, which influence male mate choice. However, little is known about the kinship or familiarity assessment of the selected partner that occurs when a male can choose between females with or without Wolbachia. To investigate the potential mechanisms leading to mate choice and the potential impact of the parasite, we performed behavioral choice tests on males where they could choose between sibling vs. nonsibling females, familiar vs. unfamiliar females, and sibling familiar vs. unfamiliar nonsibling females. To investigate the costs of inbreeding, we compared the reproductive success of both sibling and nonsibling mates. Our results revealed that male copulation attempts were higher for familiar females and for nonsibling females when both females were Wolbachia-infected, but the duration was longer when both females were Wolbachia-free. When males mated with a sibling female, their fecundity was severely decreased, consistent with inbreeding depression. Overall, we observed copulations with all types of females and demonstrated discrimination capacities and potential preferences. We highlight the complexity of the tradeoff between kinship, familiarity and parasite transmission assessment for mate choice.

Made available in DSpace on 2019-10-04T12:33:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) IBAMA The characterisation of intraspecific genetic diversity in representatives of the South American crayfish genus Parastacus Huxley, 1879 is here carried out for the first time by comparing populations of Parastacus brasiliensis (von Martens, 1869) as currently defined. Phylogenetic reconstructions based on mitochondrial and nuclear markers indicate the existence of multiple lineages, of which only one can be considered as P. brasiliensis sensu stricto. In addition, there are seven other lineages, one of which is the subspecies Parastacus brasiliensis promatensis Fontoura & Conter, 2008, which is here elevated to species level. We thereby increase to 14 the number of recognised species within Parastacus in South America. Genetic distances among P. brasiliensis sensu stricto and the lineages A', B' and C' increase with geographical distances, suggesting isolation by distance as an important driver of diversification, and eventually speciation, in these burrowing crayfishes. Parastacus brasiliensis occurs mainly in the Guaiba Lake basin and studied populations show limited connectivity and gene flow, probably due to habitat fragmentation. On the basis of genetic and distribution data, the conservation status of P. brasiliensis sensu stricto is confirmed as Near Threatened (NT). These findings lead us to encourage the establishment of preservation areas for isolated populations. The importance of preserving the newly recognised distinct gene pools in order to maintain overall genetic diversity is emphasised. Univ Estadual Paulista, Invertebrate Morphol Lab, Aquaculture Ctr, Dept Biol Aplicada, Jaboticabal, SP, Brazil Univ Fed Rio Grande do Sul, Dept Zool, Programa Posgrad Biol Anim, Porto Alegre, RS, Brazil Univ Poitiers, Lab Ecol & Biol Interact, Equipe Ecol Evolut Symbiose, CNRS,UMR 7267, Poitiers, France Univ Regensburg, Zool & Evolutionary Biol, Regensburg, Germany Univ Estadual Paulista, Invertebrate Morphol Lab, Aquaculture Ctr, Dept Biol Aplicada, Jaboticabal, SP, Brazil CNPq: 201512/2012-2 CNPq: PQ 305900/2014-5 CAPES: 1989/2014 CAPES: 737/12 IBAMA: 34299-2

Among the many alien crustacean species so far recorded in the Mediterranean basin are numerous decapods—crayfish, crabs and prawns—that have in common the reputation of being both aggressive and adaptable to various environments. Their entrance to the Mediterranean basin has often been fostered by human actions, such as the transfer of new species for commercial purposes or accidentally, as bycatch or because they were present in discarded ships’ ballast water. Marine alien species enter the Mediterranean basin from two main directions: from the Atlantic and beyond, and from the Indian Ocean via the Suez Canal. For freshwaters, the extensive European canal network is an important aid to migration, but human discards are also significant. Protection of native fauna and ecosystems is at best partial. Freshwater ecosystems particularly at risk include lagoons, river estuaries, ponds and marshes, while comparable marine systems are shallow muddy coastal regions, rocky reefs, estuaries/bays and salt marshes. Local communities, principally anglers and people working with aquatic resources, usually are curious at the appearance of a new species and the possibility of establishing a new business is often the first thought. However, freshwater decapod alien species cause major damage to agriculture production, infrastructures, riverbanks, irrigation systems and fish production, leading to consistent economic losses. In particular, they are known to be injurious to plant production, causing increasing losses to agriculture, consuming young seedlings and seeds and causing substantial water losses from field areas. Less information is available for seawater species to date, but their increasing number and growing size of populations requires the attention of the scientific community to evaluate and predict their influence on the marine environment and/or on local fish and bivalve production. Both freshwater and marine alien decapods thus represent a serious threat to native European species and have a negative impact on species richness and habitats. The economic losses caused by these species require reliable and cost-effective options for managing their abundance and if possible for their eradication.

This study was designed to evaluate the copper and zinc bioaccumulation in Orchestia montagui Audouin, 1826 which was exposed to a contaminated soil during three weeks and to determine the ultrastructural changes in the hepatopancreas of this species. Individuals were weekly weighed and the metals body burdens were determined at the end of the experiment. Furthermore, the bioaccumulation factor (BAF) was calculated showing that this species is considered as a macroconcentrator of these two metals. The highest concentrations of copper and zinc induced significant changes in the ultrastructural organization of S and B cells in the hepatopancreas.

Biological invasions are a major cause of biodiversity loss, and early action in these cases is more cost-effective than dealing with widespread invasions. Thus, understanding possible consequences of invasions is essential for control and management actions. Given the early stage of invasion of South America by Procambarus clarkii, a potentially harmful crayfish, we investigated aggressive interactions between this invasive crayfish and the native Parastacus brasiliensis to understand potential impacts of the invader on native species before they encounter each other in nature. We paired size-matched crayfish for two experiments: one with Pr. clarkii males and females against Pa. brasiliensis; and another with Pr. clarkii intraspecific interactions. We starved the crayfish then allowed to interact in the presence of food. In interspecific fights we compared the number of attacks, time with the resource, frequency of won interactions of each species and the first species to reach the resource. Regarding the interspecific fights, Pr. clarkii attacked more often, spent more time with the resource, won more interactions and reached the resource first more often than Pa. brasiliensis. Interspecific fights escalated faster than intraspecific fights. The invasive crayfish’s ability to win might be enhanced due to ownership effects, and its impact is likely to be severe because of its life-history traits. We conclude that Pr. clarkii is definitely a threat for native crayfish, requiring that immediate actions be taken, such as dam construction and manual removal of Pr. clarkii.

This study reports new records of Procambarus clarkii Girard, 1852 in Southeastern Brazil and investigates its possible pathways of introduction. The Brazilian crayfish pet trade was surveyed with regard to species’ availability and price, reporting its persistence, even though illegal. An invasion risk analysis was performed by applying a protocol developed specifically to invasive freshwater invertebrates (FI-ISK). Procambarus clarkii has confirmed occurrences from urban and non-urban areas in the state of Sao Paulo, including the Jaragua State Park, an Atlantic Forest conservation area. The pet trade is an important introduction vector but some subsequent translocation can also be due to the release of live bait by anglers. Besides passive dispersal, these newly discovered populations, especially those located in non-urban areas, are likely to naturally disperse further through active spread and river drift of juveniles. Although confirmed colonized areas are all located in the state of Sao Paulo, the invasive risk analysis showed that P. clarkii is a potential highly invasive species for Brazil. These introductions have unknown consequences; however, many impacts are associated with this species establishment around the world, underlining the urgency to understand the invasion process in Brazil and develop efficient management techniques.

International audience

In many species, males increase their reproductive success by choosing high‐quality females. In natural populations, they interact with both virgin and mated females, which can store sperm in their spermatheca. Therefore, males elaborate strategies to avoid sperm competition. In the terrestrial isopod Armadillidium vulgare, females can store sperm and produce several clutches. Moreover, this species can be parasitized by Wolbachia, which feminizes genetic males, transforming them into functional females. Our study compared attractiveness and mate choice when a male is exposed to both virgin and experienced females (i.e., females who have produced offspring and rested for 6 months), with or without Wolbachia. Our results revealed that males are more attracted to virgin females than experienced females, even if these virgin females are parasitized. Moreover, the chemical analysis highlighted different odors in females according to their reproductive and infection (Wolbachia‐free or vertically Wolbachia‐infected) status. Males attempted copulation more frequently and for longer with virgin females, even if Wolbachia‐infected, while experienced females refused further copulation. The evolutionary consequences of both male choice and female resistance on their fitness are discussed in this study.

South America is considered a world biodiversity hotspot, especially for freshwater ecosystems where there is significant biodiversity and endemism across different taxonomic groups. Native South American crayfishes are characterized by small range distributions, high levels of endemism and specific habitat requirements. Although this group may be considered one of the most threatened among South American freshwater crustaceans, IUCN Red List assessments for most of these species are ‘data deficient’. IUCN assessments are technical evaluations of species risk of extinction based on biological indicators of population features, thereby providing a ‘conservation status’ for each species based on common and international standards. Attempts to assess the conservation status of native South American crayfishes have been limited mainly owing to a lack of fundamental data and also misinterpretations of present information. Thus, a revision of the state of knowledge of native South American crayfishes (taxonomy, phylogeny and distribution, genetics, ecology and threats) was carried out coupled with IUCN assessments of conservation status. Globally, the lack of information on the biology of these species is still the major obstacle to making reliable conservation status assessments. For this reason, the Data Deficient (DD) category is still appropriate for many species. However, based on the Extent of Occurrence (EOO) and severely fragmented populations, number of locations and decline in area, extent or quality of habitat, it is recommended that some species (especially Virilastacus spp.) should be moved to threatened categories (VU, EN or CR). The data suggest that others are appropriately in the Near Threatened (NT) category, because they almost reach the thresholds for threatened categories. The assessment of conservation status is essential to support future conservation actions, especially for species allocated to threatened categories. This study has identified new species under threat and also areas for future study to provide relevant data for conservation assessment for ‘data deficient’ species. Copyright © 2014 John Wiley & Sons, Ltd.

In 2007, the invasive crayfish Procambarus clarkii (Girard 1852) was identified for the first time in the “Parc Naturel Regional de la Brenne” (Indre department, Centre region, France). Ten infestation sites were found in the park, with 62 fishponds colonised. To better understand how the fishponds could be affected, and changes in invaded ponds, we followed crayfish burrowing activity in recently drained fishponds in two areas. Weekly investigations of burrowing activity by analysing their density, occupation and location with respect to the banks, and micro-habitat features were carried out for 2 months in spring. Burrow densities of 1.16 and 1.05 burrows m–2 were found at Le Terrier Blanc and Coudreau 3 respectively. Procambarus clarkii sought humid soil in a dry pond and preferred burrowing on silt substrates. While no statistical differences were found between sites, some differences were observed among weeks independently of the sites. The mean mouth diameter of burrows in the two sites was 5.7 cm (...

International audience; : Mitochondrial DNA (mtDNA) is usually depicted as a circular molecule, however, there is increasing evidence that linearization of mtDNA evolved independently many times in organisms such as fungi, unicellular eukaryotes, and animals. Recent observations in various models with linear mtDNA revealed the presence of conserved inverted repeats (IR) at both ends that, when they become single-stranded, may be able to fold on themselves to create telomeric-hairpins involved in genome architecture conversions. The atypical mtDNA of terrestrial isopods (Crustacea: Oniscidea) composed of linear monomers and circular dimers is an interesting model to study genome architecture conversions. Here, we present the mtDNA control region sequences of two species of the genus Armadillidium: A. vulgare and A. pelagicum. All features of arthropods mtDNA control regions are present (origin of replication, poly-T stretch, GA and TA-rich blocks and one variable domain), plus a conserved IR. This IR can potentially fold into a hairpin structure and is present in two different orientations among the A. vulgare populations: either in one sense or in its reverse complement. This polymorphism, also observed in a single individual (heteroplasmy), might be a signature of genome architecture conversions from linear to circular monomeric mtDNA via successive opening and closing of the molecules.

SUMMARY 1. Climate warming often leads to shifts in the strength and sign of agonistic interactions amongspecies, which in turn may change their distribution ranges. Notwithstanding the ubiquity of thisphenomenon, there is scant literature about how interspecific agonistic behaviour changes withaltered thermal regime, especially for invasive species such as three widespread North Americancrayfishes in Europe (Orconectes limosus, Procambarus clarkii and Pacifastacus leniusculus).2. We conducted a laboratory study to analyse some descriptors of agonistic behaviour in fightingdyads of similarly sized males of the three species’ combinations, both at 20 °C (the current maxi-mum water temperature in the study area, central France) and 27 °C (the maximum expected in thenext 80 years under the more pessimistic IPCC greenhouse gas emission scenario).3. The results showed significantly different responses to warming by the three crayfishes. At 27 °C,O. limosus spent more time motionless and P. leniusculus was more often the subordinate, indepen-dent of the opponent. On the contrary, the agonistic strategy of P. clarkii did not change with temper-ature: when engaged in fighting, this species outcompeted both O. limosus and P. leniusculus.4. Caution should be taken when extrapolating laboratory studies to the field, but these results,combined with outputs of previous modelling exercises, suggest that European catchments willbecome dominated by P. clarkii with climate warming. Ultimately, this might lead to impoverishedbiodiversity, simplified food webs and altered ecosystem services.Keywords: agonistic behaviour, alien species, interspecific competition, North American crayfishes,temperature

International audience; Procambarus clarkii is currently recorded from 16 European territories. On top of being a vector of crayfish plague, which is responsible for large-scale disappearance of native crayfish species, it causes severe impacts on diverse aquatic ecosystems, due to its rapid life cycle, dispersal capacities, burrowing activities and high population densities. The species has even been recently discovered in caves. This invasive crayfish is a polytrophic keystone species that can exert multiple pressures on ecosystems. Most studies deal with the decline of macrophytes and predation on several species (amphibians, molluscs, and macroinvertebrates), highlighting how this biodiversity loss leads to unbalanced food chains. At a management level, the species is considered as (a) a devastating digger of the water drainage systems in southern and central Europe, (b) an agricultural pest in Mediterranean territories, consuming, for example, young rice plants, and (c) a threat to the restoration of water bodies in north-western Europe. Indeed, among the high-risk species, P. clarkii consistently attained the highest risk rating. Its negative impacts on ecosystem services were evaluated. These may include the loss of provisioning services such as reductions in valued edible native species of regulatory and supporting services, inducing wide changes in ecological communities and increased costs to agriculture and water management. Finally, cultural services may be lost. The species fulfils the criteria of the Article 4(3) of Regulation (EU) No 1143/2014 of the European Parliament (species widely spread in Europe and impossible to eradicate in a cost-effective manner) and has been included in the “Union List”. Particularly, awareness of the ornamental trade through the internet must be reinforced within the European Community and import and trade regulations should be imposed to reduce the availability of this high-risk species.

International audience; The crustacean cuticle is a hierarchically organised material which provides protection and sites for muscle attachment. The physical properties of this exoskeleton envelope are adapted to the function and the eco-physiological requirements of the species. This paper aimed to study, using the TEM, the structure of the tubercle and the tergite cuticle of the arid species Hemilepistus reaumurii in a comparison with a subhumid isopod in order to relate some peculiar features to an adaptive process to environmental constraints. Results showed that wild H. reaumurii cuticles were twice as thick in comparison with Porcellio variabilis which is a subhumid zone isopod. It is suggested therefore that the thick cuticle of wild H. reaumurii can be an adaptation to terrestrial life and a protection against osmotic stress and water loss in an arid environment. In addition the inside of the tubercle showed a high number of lipid droplets stacked into an adipose tissue which suggest that tubercles were used for storage for nutritive material in wild H. reaumurii.

International audience; In Tunisia, while wetlands are considered as remarkable habitats for their faunal and floral diversity, few studies on the species diversity of terrestrial isopods were performed. To fill this gap, the spatio-temporal distribution of Oniscidea at Ghar El Melh lagoon (north-east of Tunisia) was analysed. Sampling was carried out with 50 × 50 cm quadrats along a perpendicular transect to the shoreline. Nine species of terrestrial isopods belonging to seven genera were identified. Chaetophiloscia elongata Dollfus, 1884 was the most abundant species in all seasons except for summer; its relative abundance ranged from 38.9% to 77% in summer and autumn, respectively. Hill diversity indices ranged from 0.86 to 0.94 and equitability indices from 0.33 and 0.68. The statistical analysis showed a significant difference of isopod species and plant associations among seasons. En Tunisie, si les zones humides sont considérées comme des habitats remarquables pour leur diversité faunistique et floristique, peu d'études ont été faites sur la diversité des isopodes terrestres. Pour combler cette lacune, nous avons étudié la distribution spatio-temporelle des Oniscidea de la lagune de Ghar El Mehl (au nord-est de la Tunisie). L' échantillonnage a été effectué avec un quadrat 50 x 50 cm, le long d'un transect perpendiculaire à la ligne de rivage. Neuf espèces d'isopodes terrestres appartenant à sept genres ont été identifiées. Quelle que soit la saison, Chaetophiloscia elongata Dollfus, 1884 est l'espèce la plus abondante exception faite pour la saison d'été; son abondance relative varie de 38,9 à 77 % en été et en automne respectivement. L'indice de diversité de Hill varie de 0,86 à 0,94 et l'équitabilité de 0,33 à 0,68. L'analyse statistique montre une différence significative de la distribution saisonnière des isopodes terrestres en fonction des associations végétales

International audience; This field study aimed at determining the effect of metal-polluted environments on fluctuating asymmetry (FA) level of Porcellio scaber as a measure of developmental stability (DS). For this, woodlice and litter were collected on 8 sites of northern France located either away from metal pollution source or near metallurgical smelters. Physico-chemical parameters such as pH, C/N ratio and CaCO(3) were measured in litter since they could have potential effects on woodlouse population. Moreover, Cd, Pb, and Zn concentrations in litter were determined to evaluate the contamination degree of each site. The metal body burdens were determined in woodlice to evaluate their impregnation degree. Fluctuating asymmetry levels on males and gravid females were performed on 9 traits (the 2nd and the 3rd articles of antennae, the 1st flagellum segment of the antennae, and the merus, carpus and propodus of the 6th and the 7th pereiopods) according (1) to each site and (2) to two habitat types (cf. metal-contaminated and uncontaminated habitats). Results showed close correlations between litter metal concentrations and metal body burdens in woodlice. However, contrary to the initial hypothesis that metal pollution would induce an increase of the FA level, this seemed to be lower for individuals from metal-contaminated habitats than for those from uncontaminated habitats, and particularly for males. The role of antennae and pereiopods on the foraging behavior and reproduction processes on woodlice were discussed and could explain these observations. (C) 2012 Elsevier Ltd. All rights reserved.

Wolbachia bacteria are obligate intracellular alpha-Proteobacteria of arthropods and nematodes. Although widespread among isopod crustaceans, they have seldom been found in non-isopod crustacean species. Here, we report Wolbachia infection in fourteen new crustacean species. Our results extend the range of Wolbachia infections in terrestrial isopods and amphipods (class Malacostraca). We report the occurrence of two different Wolbachia strains in two host species (a terrestrial isopod and an amphipod). Moreover, the discovery of Wolbachia in the goose barnacle Lepas anatifera (subclass Thecostraca) establishes Wolbachia infection in class Maxillopoda. The new bacterial strains are closely related to B-supergroup Wolbachia strains previously reported from crustacean hosts. Our results suggest that Wolbachia infection may be much more widespread in crustaceans than previously thought. The presence of related Wolbachia strains in highly divergent crustacean hosts suggests that Wolbachia endosymbionts can naturally adapt to a wide range of crustacean hosts. Given the ability of isopod Wolbachia strains to induce feminization of genetic males or cytoplasmic incompatibility, we speculate that manipulation of crustacean-borne Wolbachia bacteria might represent potential tools for controlling crustacean species of commercial interest and crustacean or insect disease vectors.

International audience; Nowadays, the distribution of the European native white-clawed crayfish (Austropotamobius pallipes) is restricted, fragmented and mainly located in headwater streams. To preserve this indigenous species, it is necessary to characterize its habitat preferences. Although this species is endangered, little was known about its ecological requirements until recently. Recent studies conducted throughout its distribution area indicate that water pollution is the main cause of its disappearance. In particular, A. pallipes seems very sensitive to organic pollution. However, no study has focused on the macroinvertebrate assemblages that co-occur with A. pallipes. In this study, seven streams located in the Deux-Sevres Departement (western France) containing wild populations of A. pallipes were qualitatively sampled in April 2004 and Ephemeroptera were identified to species level. These sites were also sampled according to the French biotic index "IBGN" during the summer of 2004. Several chemical parameters were also analyzed e.g. Dissolved Oxygen, pH, Ca, Turbidity, UV254mm, Conductivity, Total Organic Carbon (TOC) and Total Suspended Solids (TSS) The objectives of this study were: 1) to analyze the benthic invertebrate assemblage by determining the IBGN index in both reference zone (presence of A. pallipes) and zone without crayfish, 2) to identify the Ephemeroptera community in both zones to find some match with the presence of A. pallipes. The applied issue of this study is to use both physico-chemical criteria and Ephemeroptera communities to select suitable streams for a crayfish relocation program in the Poitou-Charentes region of France. It was found that (i) the IBGN scores did not separate the sites with/without A. pallipes (ii) Ephemeroptera diversity is statistically higher in sites with crayfish than in sites without (iii) there was a strong correlation between A. pallipes, species of Ephemeroptera mainly of Leptophlebiidae family (Habrophlebia fusca, Habrophlebia lauta and Paraleptophlebia submarginata) and dissolved oxygen at the study sites.

Summary 1. Habitat fragmentation of stream ecosystems often results in decreased connectivity between populations and lower population sizes. Hence, understanding how habitat fragmentation affects genetic erosion is important for the preservation of freshwater biodiversity, in particular, as small populations suffer from loss of genetic diversity through genetic drift and loss of fitness because of inbreeding, increasing the risk of extinction. 2. Here, we assess the impact of demographic factors on population differentiation in the endangered freshwater crayfish Austropotamobius pallipes by analysing population genetic structure, estimating effective population sizes and comparing levels of polymorphism at five microsatellite loci with density estimates of 10 populations within a small French catchment that has become progressively confined to headwaters over the last six decades. 3. Levels of expected heterozygosity and allelic richness per population were relatively low (0.214–0.396 and 1.6–2.6, respectively). We found strong genetic differentiation between these geographically close populations (FST = 0.283), with weak statistical evidence for a pattern of isolation by distance. Estimates of effective population size were low (

International audience; This study aimed at determining, in the laboratory, the effects of poplar litter collected in woody habitats contaminated by heavy metals on growth and metal accumulation in the terrestrial isopod Porcellio scaber. Cd, Pb, and Zn pseudototal and CaCl(2)-extractable concentrations in litter types were determined using AAS. Juveniles were fed ad libitum, individually, for 28 days with four litter types presenting an increasing gradient of metal contamination. Individuals were weighed every week and metal body burdens were determined at the end of the experiment. From the first week until the end of the experiment, a decrease in P. scaber growth related to the increase of metal concentration in litter types was recorded. Significant correlations were observed between metal body burdens and metal concentrations in litter types. However, Cd accumulation in woodlice appeared to be related to the Cd/Zn concentration ratio in litter types. All these results showed the potential of weight gain in P. scaber as a suitable indicator for litter quality assessment with ecological relevance.

International audience; As part of the Austropotamobius pallipes species complex, the crayfish Austropotamobius italicus is a species of community interest whose preservation requires the designation of Special Areas of Conservation (SACs) (Annex II, EU Habitats Directive). This study aimed at (1) assessing the conservation status of this threatened indigenous species by stock assessment in central Italy and (2) identifying some aspects of its elective habitat.

Alien species have been transported and traded by humans for many centuries. However, with the era of globalization, biological invasions have reached notable magnitudes. Currently, introduction of alien species is one of the major threats to biodiversity and ecosystem functioning. The North American crayfish Procambarus clarkii is one of the most widely introduced freshwater species in the world, especially due to its high economic importance. It is responsible for great modifications in invaded environments causing irreparable ecological and economic damages. Its impressive ability to successfully colonize a wide range of environments is a consequence of its behavioural and biological characteristics that can adapt to features of the invaded location, conferring to this species a notable ecological plasticity. This review summarizes the available information regarding P. clarkii's biology and invasive dynamics around the world in order to contribute to the understanding of the threats posed by its establishment, as well as to support management and impact mitigation efforts.