Species Of Terrestrial Isopods Research Articles

Molecular approach challenges the monophyly of the genus Benthana Budde-Lund, 1908 (Oniscidea, Philosciidae)

ABSTRACT Although new data and methodologies are gaining prominence in the field of taxonomy, the vast majority of terrestrial isopod species are still described solely based on morphology. The genus Benthana was recently revised and currently comprises 30 species found in South America. However, the broad geographic distribution of some species, coupled with the presence of few diagnostic characters, raises doubts about the validity of the described species. This study aimed to test the applicability of DNA Barcoding to assess the congruence between morphological and molecular identification of Benthana species. We analyzed 72 individuals belonging to 13 species from the scientific collection of the UFRGS Crustacean Laboratory. We obtained 24 sequences from ten Benthana species. The molecular phylogenies demonstrated that Benthana forms a paraphyletic group. Even at the species level, paraphyletic taxa were observed. Species delimitation methods revealed the presence of eight molecular entities within Benthana. Regarding genetic distances, we observed low intra-specific distances and significantly high inter-specific distances. Our results show that molecular analysis does not support the current taxonomy of Benthana. Therefore, a reassessment of the genus systematics based on integrative taxonomy is warranted.

Iron-isopods: new records and new species of terrestrial isopods (Isopoda, Oniscidea) from Brazilian Amazon iron ore caves

Abstract. Two new species of terrestrial isopods are described from iron ore caves in Brazil, within the Amazon biome, Circoniscus mendesi López-Orozco, Campos-Filho & Bichuette sp. nov. and C. xikrin López-Orozco, Campos-Filho & Carpio-Díaz sp. nov. (Scleropactidae). In addition, the knowledge of the distribution of Ctenorillo ferrarai Campos-Filho, Araujo & Taiti, 2014 (Armadillidae) is extended to Parauapebas, and Benthanoides tarzan Cardoso & Ferreira, 2023 to south area of the Campos Ferruginosos National Park, both in the State of Pará. Moreover, a distribution map and photographs of the species are given.

Terrestrial Isopods Generate Microplastics from Low-Density Polyethylene Without Effects on Survival.

With concern growing regarding the impact of microplastics (MPs) on terrestrial ecosystems, it is important to assess the role invertebrates may play in the fate of MPs within these ecosystems. Commonly, MPs enter these environments through improperly discarded waste or the application of treated biosolids and/or wastewater on agricultural soils. The present study investigated whether three species of terrestrial isopod (Porcellio scaber, Porcellio laevis, and Porcellionides pruinosus) ingest plastic debris and generate MPs during exposures varying from 24 h to 14 days and whether this may have an adverse effect on their health. Test vessels were designed to expose isopods to plastic fragments in the form of polyethylene plastic foam. Isopods were exposed to plastic that was either (1) pristine, or (2) weathered in a soil and water solution prior to incorporation in test vessels. When exposed to weathered polyethylene, all three species generated MPs (minimum-maximum size values for all durations inclusive: P. laevis = 114-1673 µm, P. scaber = 99-1635 µm, P. pruinosus = 85-1113 µm) through the consumption of macroplastic fragments with no observed impact on their health. In the shorter-duration exposures, the number of MPs generated by the isopod species in the present study was highly variable between experimental vessels (minimum-maximum generated MPs for 14-day exposure: P. laevis = 25-420, P. scaber = 50-583, P. pruinosus = 48-311). However, as the exposure durations increased, there was a clear trend of increasing MP generation, indicating that the isopods continued to consume the plastic fragments as long as the surface was weathered. A significant difference in the size of generated MPs was observed as well, with smaller isopod species generating smaller MP fragments on average. The results of the present study confirm that certain species of isopod can contribute to the generation of MPs, which constitutes an additional pathway of MP exposure to soil ecosystems. Environ Toxicol Chem 2024;43:784-792. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Effects of moisture decrease on behavioural and life history traits in three species of terrestrial isopods

In the context of the predicted global warming, we investigated whether the feeding activity and the behaviour of three Oniscidean species (Porcellionides pruinosus, Porcellio laevis and Armadillidium tunisiense) would be affected by the relative humidity (RH) decrease. A decreasing gradient of relative humidity (90%, 70% and 50%) was used to study the impact of predicted climate change on the survival rate, litter consumption rate, growth efficiency, faeces production, localization and stress behaviour within woodlice. After 3 weeks of exposure, we found that all species were variously affected by the RH decrease. The species A. tunisiense showed to be the least affected by the increased dry conditions. In driest conditions, woodlice spend less time at foraging inducing a low rate of litter consumption and faeces production. Perhaps, the authors findings could contribute to changes in the decomposition process and then the soil functionality.

First record of the genus Desertoniscus Verhoeff, 1930 (Isopoda: Agnaridae) from Iran, with the description of a new species

A new species of terrestrial isopod, Desertoniscus iranensis n. sp., is described from Qeshm Island, southern Iran, representing the first record of the genus Desertoniscus for Iran. A description of the new species is provided and its diagnostic characters are illustrated. http://www.zoobank.org/urn:lsid:zoobank.org:pub:2DDFE22F-6BFF-4221-A520-58CD5AF19A79

Fungal Diversity Associated with Armadillidium Isopods: A Case Study in Central Park of Gwacheon, South Korea

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.

New Species of Terrestrial Isopods (Crustacea, Isopoda, Oniscidea) from Liguria and Surrounding Regions, Northern Italy

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.

Diversification within an oceanic Mediterranean island: Insights from a terrestrial isopod

Understanding intra-island patterns of evolutionary divergence, including cases of cryptic diversity, is a crucial step towards deciphering speciation processes. Cyprus is an oceanic island isolated for at least 5.3 Mya from surrounding continental regions, while it remains unclear whether it was ever connected to the mainland, even during the Messinian Salinity Crisis. The terrestrial isopod species Armadillo officinalis, that is widespread across the Mediterranean, offers the opportunity to explore intra-island divergence patterns that might exhibit geographical structure related also to the region’s known paleogeography. Genome-wide ddRADseq, as well as Sanger sequencing for four mitochondrial and three nuclear loci data were generated for this purpose. In total, 71 populations from Cyprus, neighbouring continental sites, i.e., Israel, Lebanon and Turkey, and other Mediterranean regions, i.e. Greece, Italy, and Tunisia, were included in the analysis. Phylogenetic reconstructions and population structure analyses support the existence of at least six genetically discrete groups across the study area. Five of these distinct genetic clades occur on Cyprus, four of which are endemic to the island and one is widely distributed along the circum-Mediterranean countries. The sixth clade is distributed in Israel. The closest evolutionary relationship of endemic Cypriot populations is with those from Israel, while the evolutionary clade that is present in countries all around the Mediterranean is very shallow. Cladochronological analyses date the origin of the species on the island at ∼6 Mya. Estimated f4 and D statistics as well as FST values indicate the genetic isolation between the populations sampled from Cyprus and surrounding continental areas, while there is evident gene flow among populations within the island. Species delimitation and population genetic metrics support the existence of three distinct taxonomic units across the study area, two of which occur on the island and correspond to the endemic clade and the widespread circum-Mediterranean one, respectively, while the third corresponds to Israel’s clade. The islands’ paleogeographic history and recent human activities seem to have shaped current patterns of genetic diversity in this group of species.

Cuticle structure of Carpathian endemic species: Trachelipus trilobatus (Crustacea, Isopoda, Oniscidea) described with the scanning electron microscope

The cuticle is the interface between an animal and its environment; thus, it has a special importance. In Arthropods, the cuticle is not uniform, having numerous formations, which is also the case of epigeic terrestrial isopods. Our study presents data on cuticle surface morphology, obtained with a scanning electron microscope, of an endemic terrestrial isopod species, Trachelipus trilobatus. Here we present SEM images of some external morphological features of this species, which were previously described only at the light microscope. Although T. trilobatus was frequently encountered in caves, the aspect of its cuticle is characteristic for an epigeic isopod, presenting numerous micro-scales, spines, and tricorn sensilla, which are considered hygroreceptors. This fact proves that originally T. trilobatus is an epigeic species, which secondarily adapted to karst areas with caves. Nevertheless, it regularly leaves the caves and the limestone cracks and emerges on the soil surface. Therefore, T. trilobatus is able to receive information about environmental humidity, especially on the soil surface, which, when unfavorable, causes the species retreat into caves or cracks. Climatic fluctuations from the glacial periods could direct T. trilobatus to this environment and way of life, modifying its morphology, but not its cuticle.

Bug cemetery: a case study of terrestrial isopod distribution on a brick wall in the Czech Republic.

Although terrestrial isopods (Oniscidea) are primarily soil- and surface-dwelling invertebrates, they can also be found on tree trunks and walls. This study evaluated distribution patterns of terrestrial isopods on a brick wall during the first hours of night in autumn. Four species of terrestrial isopods were recorded with Armadillidiumversicolor being the dominant one. Terrestrial isopods were distributed from ground level up to a height of 2 m, but preferred a 70-80 cm height band. The highest number of active individuals was observed 3 h after astronomical dusk. Potential predators of terrestrial isopods were abundant during the same time and at the same height.

Intersexuality in a natural population of the terrestrial isopod Porcellioscaber.

Intersex phenotypes are rarely observed in natural isopod populations and their expression is typically associated with infection of Wolbachia, a reproductive parasite that manipulates arthropod reproduction. During an intensive sampling effort of a natural population of the isopod Porcellioscaber, an adult individual was isolated that expressed both male and female traits. The intersex individual exhibited clearly developed external male genitalia and carried multiple eggs in its brood pouch. No Wolbachia infection could be identified in this individual, a result that needs to be approached with caution due to suboptimal DNA preservation for diagnostic PCR assays. Wolbachia were, however, detected in two adult females of the same population, and appear closely related to isolates that infect other terrestrial isopod species. This is the first demonstration that intersex phenotypes can arise under natural conditions in P.scaber.

Inventory of the terrestrial isopods in Belgium (2011-2020).

This data paper describes a recent and spatially complete inventory of the terrestrial isopods of Belgium between 2011 and 2020. During these 10 years every 10 × 10 km² cell of the Universal Transverse Mercator (UTM) grid in Belgium (373 grid cells) was visited in search for terrestrial isopods. Inventories covered different habitat types in every grid cell such as forest, wetlands or stream sides, and urban areas. Most of the dataset records were obtained by hand-collection methods such as turning stones and dead wood, or by sieving litter and through casual observations. These inventories were carried out by specialists from Spinicornis, the Belgian Terrestrial Isopod Group. Their data is complemented with pitfall trap data from scientific projects and verified citizen science data collected via waarnemingen.be and observations.be from the same time period. This resulted in 19,406 dataset records of 35 terrestrial isopod species. All dataset records are georeferenced using the centroid of their respective 5 × 5 km² UTM grid cell. The dataset is published as open data and available through the Global Biodiversity Information Facility (GBIF). Direct link to the dataset: https://doi.org/10.15468/mw9c66.

Description of the postmarsupial manca stages of Armadillidium ficalbii (Crustacea, Isopoda, Oniscidea)

ABSTRACT The postmarsupial manca stages of Armadillidium ficalbii Arcangeli, 1911 were studied in detail by morphological analysis. Ovigerous females were reared separately under controlled conditions, allowing us to follow the stages of development from release from the marsupium until the appearance of the first juvenile stage, identified by the full development of the seventh pair of pereopods. Each newborn was followed to record the subsequent moults that identify the three postmarsupial manca stages. Manca stage M I had a mean duration of 10 h, manca stage M II 8–9 days, and manca stage M III 9–10 days. The cephalothorax width was measured to provide a growth measure for each stage. The mean values of the cephalothorax width were: 0.589 mm for M I, 0.718 mm for M II and 1.274 mm for M III. The morphological modifications in the three postmarsupial manca stages were described, the body parts illustrated, and SEM images taken. The distinguishing characteristics among mancas were discussed, and comparisons made with manca stages of other terrestrial isopod species.

Catalogue of terrestrial isopods (Isopoda, Oniscidea) from Peru, with new records of Circoniscus ornatus (Scleropactidae) and Ethelum americanum (Eubelidae)

This work aims to list all known species of terrestrial isopods from Peru until September, 2020. Also, Circoniscus ornatus (Verhoeff, 1941) (Scleropactidae) and Ethelum americanum (Dollfus, 1896) (Eubelidae) are recorded for the first time from Nueva Alianza and Nuevo Sucre, Contamana, Loreto department, Peruvian Amazon rainforest.

Agnara cavernicola, the second troglophilic terrestrial isopod species (Isopoda: Oniscidea) from Iran

ABSTRACT The first cave-dwelling terrestrial isopod species of the genus Agnara Budde-Lund, 1908 is described from Zarneh Cave, western Iran. Agnara cavernicola Bakhshi and Kashani, sp. nov. is characterised by a reduced number of ommatidia and body pigments. Moreover, it differs from the congeneric species by the shape of male pleopod exopodites I and male pereopods VII. http://urn:lsid:zoobank.org:pub:B0DDD1CE-B6B6-44A9-A8AC-E2AF3F0EBE54

Contribution to the knowledge of the terrestrial isopod fauna of Lithuania

The present survey provides records on terrestrial isopods from southern and north-western parts of Lithuania. Isopods were sampled manually by checking substrates in eight habitats (several types of forest and anthropogenic environment) between 2014 and 2016. In total, seven species were recorded. The common European species Trachelipus rathkii was noted as the most frequent isopod in all studied habitats from southern Lithuania. Porcellionides pruinosus, found in the habitat of anthropogenic activity, was recorded for the first time from Lithuania. Based on the data of the present study and previous surveys, the 14 species of terrestrial isopods are recorded in Lithuania and the current state of knowledge about Lithuanian isopod is summarised.

Preliminary data on terrestrial isopods from some railways in Dobruja, eastern Romania

In July 2020 we analyzed the terrestrial isopod assemblages from different (mostly abandoned) railway constructions in Dobruja, eastern Romania. We identified 10 terrestrial isopod species, of which the most abundant and frequent were Porcellionides pruinosus (Brandt, 1833) and Armadillidium vulgare Latreille, 1804. We identified species that, in Romania, are present only in Dobruja: Leptotrichus pilosus Dollfus, 1905 and Trachelipus squamuliger (Verhoeff, 1907). Most of the species are common, generalist or synanthropic, connected to dry and open habitats. In abandoned railway-stations the number of species/samples was low (at most two), but at the base of a stone railway bridge in Babadag forest six species were found.

Structure of a hinge joint with textured sliding surfaces in terrestrial isopods (Crustacea: Isopoda: Oniscidea)

BackgroundThe study of joints in terrestrial arthropods can provide insights into the evolutionary optimization of contacting surfaces that slide without lubrication. This work reports on the structure of the joint between the propodus and the dactylus in terrestrial isopods, the most successful group of crustaceans on land, focusing on the woodlouse Porcellio scaber.MethodsThe joints were studied using fluorescence microscopy, 3D reconstruction, scanning electron microscopy and transmission electron microscopy. The obtained results were functionally interpreted using high-speed video recordings by analyzing the use of the joint during locomotion.ResultsIn the joint, which allows the dactylus to move in a single plain, a semicircular process on the propodus fits into a groove on the dactylus and guides its movement. The sliding surfaces of the propodal process are textured in the form of parallel epicuticular ridges a few hundred nanometers thick. This texturing is selective: while the less heavily loaded surfaces are textured, the surfaces that support the isopod during standing and walking are smooth. In contrast, the groove on the dactylus is completely smooth. We found a similar surface texture in several other species of terrestrial isopods and one aquatic isopod.ConclusionsThe selective texturing of the joint may reduce wear by eliminating small particles. This effect of the ridges was confirmed using electron microscopy. The absence of ridges on heavily loaded surfaces may enhance the dissipation of forces in these regions.

Supergroup F Wolbachia in terrestrial isopods: Horizontal transmission from termites?

Horizontal transmission between distantly related species has been used to explain how Wolbachia infect multiple species at astonishing rates despite the selection for resistance. Recently, a terrestrial isopod species was found to be infected by an unusual strain of supergroup F Wolbachia. However, only Wolbachia of supergroup B is typically found in isopods. One possibility is that these isopods acquired the infection because of their recurrent contact with termites—a group with strong evidence of infection by supergroup F Wolbachia. Thus, our goals were: (1) check if the infection was an isolated case in isopods, or if it revealed a broader pattern; (2) search for Wolbachia infection in the termites within Brazil; and (3) look for evidence consistent with horizontal transmission between isopods and termites. We collected Neotroponiscus terrestrial isopods and termites along the Brazilian coastal Atlantic forest. We sequenced and identified the Wolbachia strains found in these groups using coxA, dnaA, and fpbA genes. We constructed phylogenies for both bacteria and host taxa and tested for coevolution. We found the supergroup F Wolbachia in other species and populations of Neotroponiscus, and also in Nasutitermes and Procornitermes termites. The phylogenies showed that, despite the phylogenetic distance between isopods and termites, the Wolbachia strains clustered together. Furthermore, cophylogenetic analyses showed significant jumps of Wolbachia between terrestrial isopods and termites. Thus, our study suggests that the horizontal transmission of supergroup F Wolbachia between termites and terrestrial isopods is likely. Our study also helps understanding the success and worldwide distribution of this symbiont.Supplementary informationThe online version of this article (10.1007/s10682-021-10101-4) contains supplementary material, which is available to authorized users.

<em>Cristarmadillidium zaragozai</em> n. sp. (Oniscidea, Armadillidiidae), un nuevo isópodo terrestre de la península ibérica

En este trabajo se describe una nueva especie de isópodo terrestre de la familia Armadillidiidae del levante español, C. Zaragozai n. sp. Se discuten sus caracteres diagnósticos que permiten separarla de las otras dos especies del género.
 
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