Search Results (17)

(1) Studying the spatial distribution of wingless arthropods restricted to the Earth’s surface presents numerous challenges. In this study, we focused on the spatial distribution of terrestrial isopods (Oniscidea) within a managed forest ecosystem, examining relationships among abundance, variance, occupancy, and clumpiness (i.e., aggregation) to highlight their significant roles in the observed phenomena. (2) Terrestrial isopods were collected using pitfall traps along a gradient spanning deforested and forested areas. For analysis, we employed summary statistics to describe the community using 18 different coefficients. Abundance–variance and abundance–occupancy models, together with Taylor’s power law and ordination symbol plots were performed. (3) Nearly 1000 individuals representing 8 species were identified and analyzed. All species exhibited a clumped distribution; however, Ligidium hypnorum displayed the highest degree of clumpiness, which resulted in notably low frequency and constancy despite its high overall abundance. Shrubs were the habitat with the highest rate of aggregation. Most species concentrated their individuals in just up to 5 of the 75 pitfall traps, with the remaining traps typically containing fewer or no individuals. (4) Species that are highly abundant on a local scale can be surprisingly limited in their spatial distribution, making their assumed dominance questionable and causing them to deviate from established trends. Awareness of species-specific traits and attention to such details can progressively improve the interpretation of observed ecological patterns. Full article

The ability of terrestrial isopods (Crustacea: Isopoda: Oniscidea) to protect themselves effectively from predation by birds has never been tested. They are equipped with glands producing chemical substances; moreover, some species show conspicuous coloration, which might suffice as an aposematic signal. We evaluated the palatability of isopods to birds. We tested the responses of Parus major captured in the wild (and thus possessing some experience with common native isopod species) to the following isopod species: Porcellio scaber (native, inconspicuous), Oniscus asellus (native, moderately conspicuous), Armadillo officinalis (non-native, moderately conspicuous), Armadillidium versicolor (native, conspicuous), and Armadillidium gestroi (non-native, conspicuous). We compared bird responses to isopods with reactions to the Blaptica dubia, an edible roach very similar to isopods in size and appearance. Isopods were better protected from bird attacks than roaches; however, their color pattern did not affect the level of protection. Birds were able to differentiate isopods from the roach; in experiments, where we presented isopod and roach individuals together, the birds hesitated longer in attacking and observed both prey items for a longer time. Non-native species either profited from the generalization of the protection of native isopods or from neophobia. Some isopods elicited significantly more discomfort behavior in birds, suggesting differences in the chemical protection among the tested species. Full article

Three new species of Trichorhina are described from iron ore caves in the Serra dos Carajás Mountain Range, located in the Amazon Forest, Brazil. Trichorhina tucupi n. sp. occurs in Serra Leste, Serra da Bocaina and Serra do Tarzan Mountain Ranges. Trichorhina tacaca n. sp. occurs in caves in the Serra Norte Mountain Range. Trichorhina piloi n. sp. occurs in the Serra Sul and Serra Norte Mountain Ranges. Statistical methods were applied to investigate the putative morphological patterns of these species and to investigate their potential use in distinguishing Trichorhina species from epigean and hypogean habitats. Full article

Since 2015, the invasive seaweed Rugulopteryx okamurae has triggered the most serious marine macrophyte invasion in Europe. Its huge coastal biomass dumped on beaches generates health problems, strong odors, impacts on tourism, and high clean-up costs, but it also constitutes a new potential marine resource that offers significant prospects for exploitation. In this sense, as a circular economy strategy, seaweed bioremediation with isopods (Isopoda, Crustacea, Arthropoda) was experimented on for the first time. Specimens of Porcellio laevis (native terrestrial isopod) were obtained from urban parks and kept in terrariums with adequate humidity and temperature control. A sample of 150 adult specimens was divided into six batches of 25 animals. Three batches were fed with 100 g of mulch of Quercus pyrenaica leaves (control) and three with a diet composed of 100 g of mulch of algae (treatment). P. laevis consumed up to 1.5 times their weight per day on the algae diet, with little or no weight loss and adequate reproduction rates. The weight of the isopods averaged 1.6 g in the seaweed group and 2.5 g in the control group. However, high mortality was observed in both mancas and adults in the treatment group. In this sense, the average number of mancas per cm² was 0 in the algae group and 325 in the control group. Despite this, the results are promising, and consequently, we propose to encourage research with isopods due to their high voracity, high prolificacy, and resistance to invasive algal recycling. Future work should explore what percentage of R. okamurae prevents diterpene mortality of isopods and other invertebrates. This is a preliminary step towards the massive bioremediation of spring and summer blooms of R. okamurae. This work contributes to highlighting this abundant marine resource. Full article

(1) Car tyre microplastic particles (TMPs) significantly contribute to global microplastic pollution, with an estimated annual production of 6 million tonnes. However, the impact of TMPs, particularly tyre and road wear particles (TRWPs), resulting from tyre abrasion on the road on terrestrial organisms, is poorly understood. This study investigated the effects of TMPs and TRWPs on the growth, immune response, behaviour, and cognition of the woodlouse Armadillidium pallasii over 30 days; (2) TMPs and TRWPs were mixed together in the first experiment and provided at different concentrations of 1.25%, 2.5%, 5%, and 10% (w/w), and with soil at 5% and 10% (w/w) concentrations in the second experiment. (3) No differences in survival or immune responses were observed in both experiments. However, isopods exposed to TRWPs showed significant weight gain at lower concentrations but no gain at higher levels. Behavioural tests revealed increased vigilance in TRWP-exposed animals. Micro-FTIR analysis showed that the number of TMPs and TRWPs in the isopods correlated with soil concentrations, and particle size decreased during the experiment. (4) The study highlights the physiological and behavioural effects of TRWPs and the role of detritivorous species in the biofragmentation of TMPs and TRWPs, contributing to the biogeochemical plastic cycle. Full article

A fossil of Oniscidea, Tylidae gen. et sp. indet. from Kachin amber (Cretaceous Cenomanian), Myanmar, is described here. The convex body, the cephalon with a triangular protrusion between the antennae, and pereonites 2–6 with epimera demarcated from tergites indicate that this specimen belongs to the family Tylidae, but since it is not an adult the identification of the genus and species is uncertain. This specimen has a convex body and shows an ability to conglobate, like all Tylidae. It is the first specimen of Oniscidea with a conglobation ability found in Burmese amber. Up to now, the fossil record of terrestrial isopods has included a total of 20 families and 54 records (36 species and 18 not formally identified species), 20% of which are from the Cretaceous period. These fossil records from the Cretaceous period show that terrestrial isopods were highly diversified as early as in the Cenomanian. Full article

The symbiotic relationship between macroorganisms, such as plants and animals, and the microorganisms in their environment plays a crucial role in shaping their physiology and ecology. Thus, many studies have examined microbial symbiosis in relation to plants, humans, and insects. However, little is known about the microbial diversity associated with isopods. Hence, in this study, we investigated the fungal diversity associated with two species of terrestrial isopods, Armadillidium nasatum and A. vulgare. In this study, we used a metabarcoding approach to compare fungal diversity between the two species for the first time. Our results indicated that A. nasatum had significantly greater mycobiome alpha diversity than A. vulgare. In contrast, fungal communities (beta diversity) did not differ significantly between hosts, except in beta dispersion of relative abundance. The majority of fungi identified belonged to Ascomycota and Basidiomycota, phyla that are dominated by saprotrophs. In conclusion, our findings shed light on the fungal communities associated with Armadillidium species, providing valuable insight into the biology of terrestrial isopods. Full article

Five new species of terrestrial isopods from Liguria and surrounding regions are described: Buddelundiella zoiai sp. n. (Buddelundiellidae), Sardoniscus marmoratus sp. n. (Oniscidae), Cylisticus poggii sp. n. (Cylisticidae), Porcellio incavatus sp. n. (Porcellionidae), and Alloschizidium segestanum sp. n. (Armadillidiidae). Buddelundiella zoiai, Cylisticus poggii and Alloschizidium segestanum were collected in edaphic environments, while Sardoniscus marmoratus and Porcellio incavatus were found in leaf litter or under not deeply embedded rocks. The diagnostic characters, the affinities and the distribution of the new species are discussed. Full article

Terrestrial isopods are effective herbivorous scavengers with an important ecological role in organic matter cycling. Their guts are considered to be a natural enrichment environment for lignocellulosic biomass (LCB)-degrading bacteria. The main goal of this work was to assess the structural diversity of Porcellio dilatatus gut bacterial communities using NGS technologies, and to predict their functional potential using PICRUSt2 software. Pseudomonadota, Actinomycetota, Bacillota, Cyanobacteria, Mycoplasmatota, Bacteroidota, Candidatus Patescibacteria and Chloroflexota were the most abundant phyla found in P. dilatatus gut bacterial communities. At a family level, we identified the presence of eleven common bacterial families. Functionally, the P. dilatatus gut bacterial communities exhibited enrichment in KEGG pathways related to the functional module of metabolism. With the predicted functional profile of P. dilatatus metagenomes, it was possible to envision putative symbiotic relationships between P. dilatatus gut bacterial communities and their hosts. It was also possible to foresee the presence of a well-adapted bacterial community responsible for nutrient uptake for the host and for maintaining host homeostasis. Genes encoding LCB-degrading enzymes were also predicted in all samples. Therefore, the P. dilatatus digestive tract may be considered a potential source of LCB-degrading enzymes that is not to be neglected. Full article

Terrestrial isopods, a diverse group of small crustaceans, are a beneficial component of a healthy ecosystem. Terrestrial isopods are also excellent living animals to have in a middle school science classroom. The current study evaluated if future middle school science teachers would utilize living terrestrial isopods in their classroom, and if they would not, to what extent fear and disgust towards arthropods was a factor that influenced their decision to avoid them. Before the terrestrial isopod activities, the teachers had moderate fear and moderate disgust toward terrestrial isopods and had no desire to teacher their students about terrestrial isopods. After participating in the terrestrial isopod activities, the teachers had no fear and no disgust toward terrestrial isopods and had a strong desire to teach their students about terrestrial isopods. Based on the findings of this study, new discoveries and powerful recommendations are presented that are relevant to those that are involved in the preparation of future middle school science teachers and those that provide professional development for current middle school science teachers. Full article

Fusarium solani, a soil-borne pathogen of stored potato may be disseminated, and thus, the damage caused by the pathogen may be aggravated by the grazing activities of arthropods. To investigate whether terrestrial woodlice contribute to the spread or, instead, to the control of F. solani, we launched a series of pilot experiments. First, a laboratory feeding trial was set up to find whether and to what extent woodlice consume the mycelia of fungal pathogens, namely, Aspergillus niger, F. solani, Macrophomina phaseolina, and Sclerotinia sclerotiorum. This was followed by a second set of experiments to simulate storage conditions where potato tubers, either healthy or infected with F. solani, were offered to woodlice. We found that: (1) F. solani was accepted by woodlice but was not their most preferred food source; (2) the presence of woodlice reduced the spread of F. solani among potato tubers. Our results suggest that the classification of terrestrial woodlice as “storage pests” needs re-evaluation, as isopods have the potential to disinoculate infective plant remnants and, thus, reduce the spread of storage pathogens. Full article

Exposed regions of the arthropod exoskeleton have specialized structure and mineral composition. Their study can provide insights into the evolutionary optimization of the cuticle as a material. We determined the structural and compositional features of claws in the crustacean Ligia pallasii using X-ray micro-computed tomography, scanning electron microscopy (SEM), and analytical scanning transmission electron microscopy (STEM). In addition, we used nanoindentation to determine how these features fine-tune the mechanical properties of the claw cuticle. We found that the inner layer of the claw cuticle—the endocuticle—contains amorphous calcium phosphate, while the outer layer—the exocuticle—is not mineralized and contains elevated amounts of bromine. While the chitin–protein fibers in crustacean exoskeletons generally shift their orientation, they are aligned axially in the claws of L. pallasii. As a consequence, the claw cuticle has larger elastic modulus and hardness in the axial direction. We show that amorphous calcium phosphate mineralization and the brominated cuticle are widespread in isopod crustaceans inhabiting terrestrial habitats. We discuss how the features of the claw cuticle may aid in minimizing the likelihood of fracture. Ultimately, our study points out the features that increase the durability of thin skeletal elements. Full article

We compared the changes of selected immune parameters of Porcellio scaber to different stressors. The animals were either fed for two weeks with Au nanoparticles (NPs), CeO₂ NPs, or Au ions or body-injected with Au NPs, CeO₂ NPs, or lipopolysaccharide endotoxin. Contrary to expectations, the feeding experiment showed that both NPs caused a significant increase in the total haemocyte count (THC). In contrast, the ion-positive control resulted in a significantly decreased THC. Additionally, changes in phenoloxidase (PO)-like activity, haemocyte viability, and nitric oxide (NO) levels seemed to depend on the stressor. Injection experiments also showed stressor-dependant changes in measured parameters, such as CeO₂ NPs and lipopolysaccharide endotoxin (LPS), caused more significant responses than Au NPs. These results show that feeding and injection of NPs caused an immune response and that the response differed significantly, depending on the exposure route. We did not expect the response to ingested NPs, due to the low exposure concentrations (100 μg/g dry weight food) and a firm gut epithelia, along with a lack of phagocytosis in the digestive system, which would theoretically prevent NPs from crossing the biological barrier. It remains a challenge for future research to reveal what the physiological and ecological significance is for the organism to sense and respond, via the immune system, to ingested foreign material. Full article

Movile Cave hosts one of the world’s most diverse subsurface invertebrate communities. In the absence of matter and energy input from the surface, this ecosystem relies entirely on in situ primary productivity by chemoautotrophic microorganisms. The energy source for these microorganisms is the oxidation of hydrogen sulfide provided continuously from the deep thermomineral aquifer, alongside methane, and ammonium. The microbial biofilms that cover the water surface, the cave walls, and the sediments, along with the free-swimming microorganisms, represent the food that protists, rotifers, nematodes, gastropods, and crustacean rely on. Voracious water-scorpions, leeches, and planarians form the peak of the aquatic food web in Movile Cave. The terrestrial community is even more diverse. It is composed of various species of worms, isopods, pseudoscorpions, spiders, centipedes, millipedes, springtails, diplurans, and beetles. An updated list of invertebrate species thriving in Movile Cave is provided herein. With 52 invertebrate species (21 aquatic and 31 terrestrial), of which 37 are endemic for this unusual, but fascinating environment, Movile Cave is the first known chemosynthesis-based groundwater ecosystem. Therefore, Movile Cave deserves stringent attention and protection. Full article

In crustaceans, antimicrobial peptides (AMPs) are clustered into four major groups according to their amino acid composition and structure: (1) single-domain peptides containing cysteine residues such as anti-lipopolysaccharide-factor (ALF), (2) multi-domain or chimeric AMPs such as crustins, (3) non-conventional AMPs, and (4) linear single-domain AMPs. The majority of AMPs has been described in commercially exploited crustaceans, particularly decapods living in aquatic environments (crab, shrimp, lobster, and crayfish). Here, we aimed at establishing the AMPs repertoire of terrestrial isopods (Oniscidea), an original suborder of crustaceans adapted to life outside of the aquatic environment. Using transcriptomic data from 21 species, we identified 110 ALF and 73 crustin sequences. We also characterized the full-length sequence of armadillidins from 17 species, similar to the AMP previously described in the terrestrial isopod Armadillidium vulgare. Furthermore, we tested the antimicrobial activity of three armadillidin peptides characterized from three distantly related species. This analysis revealed similar activity spectra against pathogens, despite extensive structural variation among the tested peptides. In addition to conventional crustacean AMPs, our work highlights armadillidins as a new and independent family of AMPs specific to the Oniscidea, thus opening new perspectives concerning the study of the immune system of terrestrial isopods. Full article