Artioposthia Triangulata Research Articles

The invasive land flatworm Arthurdendyus triangulatus has repeated sequences in the mitogenome, extra-long cox2 gene and paralogous nuclear rRNA clusters

Using a combination of short- and long-reads sequencing, we were able to sequence the complete mitochondrial genome of the invasive ‘New Zealand flatworm’ Arthurdendyus triangulatus (Geoplanidae, Rhynchodeminae, Caenoplanini) and its two complete paralogous nuclear rRNA gene clusters. The mitogenome has a total length of 20,309 bp and contains repetitions that includes two types of tandem-repeats that could not be solved by short-reads sequencing. We also sequenced for the first time the mitogenomes of four species of Caenoplana (Caenoplanini). A maximum likelihood phylogeny associated A. triangulatus with the other Caenoplanini but Parakontikia ventrolineata and Australopacifica atrata were rejected from the Caenoplanini and associated instead with the Rhynchodemini, with Platydemus manokwari. It was found that the mitogenomes of all species of the subfamily Rhynchodeminae share several unusual structural features, including a very long cox2 gene. This is the first time that the complete paralogous rRNA clusters, which differ in length, sequence and seemingly number of copies, were obtained for a Geoplanidae.

Development and application of a multilingual electronic decision-support tool for risk screening non-native terrestrial animals under current and future climate conditions

Electronic decision-support tools are becoming an essential component of government strategies to tackle non-native species invasions. This study describes the development and application of a multilingual electronic decision-support tool for screening terrestrial animals under current and future climate conditions: the Terrestrial Animal Species Invasiveness Screening Kit (TAS-ISK). As an adaptation of the widely employed Aquatic Species Invasiveness Screening Kit (AS-ISK), the TAS-ISK question template inherits from the original Weed Risk Assessment (WRA) and related WRA-type toolkits and complies with the ‘minimum requirements’ for use with the recent European Regulation on invasive alien species of concern. The TAS-ISK consists of 49 basic questions on the species’ biogeographical/historical traits and its biological/ecological interactions, and of 6 additional questions to predict how climate change is likely to influence the risks of introduction, establishment, dispersal and impact of the screened species. Following a description of the main features of this decision-support tool as a turnkey software application and of its graphical user interface with support for 32 languages, sample screenings are provided in different risk assessment areas for one representative species of each of the main taxonomic groups of terrestrial animals supported by the toolkit: mammals, birds, reptiles, amphibians, annelids, insects, molluscs, nematodes, and platyhelminths. The highest-scoring species were the red earthworm Lumbricus rubellus for the Aegean region of Turkey and the New Zealand flatworm Arthurdendyus triangulatus for Croatia. It is anticipated that adoption of this toolkit will mirror that of the worldwide employed AS-ISK, hence allowing to share information and inform decisions for the prevention of entry and/or dispersal of (high-risk) non-native terrestrial animal species – a crucial step to implement early-stage control and eradication measures as part of rapid-response strategies to counteract biological invasions.

Genetic variability of Arthurdendyus triangulatus (Dendy, 1894),a non-native invasive land planarian.

Arthurdendyus triangulatus (Dendy, 1894) is a land planarian native to New Zealand which has become established in the United Kingdom and the Faroe Islands during the last 60 years. The species has become prevalent and widely established in Scotland mediated by human activity mostly through the exchange of plants and associated soil. As a predator of earthworms, concerns regarding both the direct impact on earthworm abundance and diversity and the indirect impact on those birds and mammals that have earthworms as a primary dietary component led to A. triangulatus being the subject of both national and EU regulation. Whilst much is known regarding the ecology of A. triangulatus there is a significant knowledge gap regarding the genetic variability of the species. Using four DNA target regions cytochrome oxidase (CoI), elongation factor (EF), internal transcribed spacer region (ITS-1) and large subunit (LSU), we characterised the genetic variability of A. triangulatus populations across its full geographic range in Scotland and included a few populations from New Zealand, England and Northern Ireland. Two DNA regions, ITS-1 and CoI, revealed inter-population variability yielding well supported genetic structure in predominantly Scottish populations. We also identified considerable intra-specific and intra-individual heterogeneity in both ribosomal and mitochondrial regions, including the prevalence of pseudo-gene nuclear encoded mitochondrial DNA (Numt), the latter not previously reported for Platyhelminthes. Furthermore, given the presence of multiple ITS-1 haplotypes in individual specimens of A. triangulatus it is not possible to make definitive comment to support previously published findings that A. triangulatus was subjected to multiple introductions into the UK.

First report of the land planarian Diversibipalium multilineatum (Makino & Shirasawa, 1983) (Platyhelminthes, Tricladida, Continenticola) in Europe.

First report of the land planarian Diversibipalium multilineatum (Makino & Shirasawa, 1983) (Platyhelminthes, Tricladida, Continenticola) in Europe.

The invasive New Guinea flatworm Platydemus manokwari in France, the first record for Europe: time for action is now.

Non-indigenous terrestrial flatworms (Platyhelminthes) have been recorded in thirteen European countries. They include Bipalium kewense and Dolichoplana striata that are largely restricted to hothouses and may be regarded as non-invasive species. In addition there are species from the southern hemisphere such as the invasive New Zealand flatworm Arthurdendyus triangulatus in the United Kingdom, Eire and the Faroe Islands, the Australian flatworm Australoplana sanguinea alba in Eire and the United Kingdom, and the Australian Blue Garden flatworm Caenoplana coerulea in France, Menorca and the United Kingdom. The United Kingdom has some twelve or more non-indigenous species most of which are Australian and New Zealand species. These species may move to an invasive stage when optimum environmental and other conditions occur, and the flatworms then have the potential to cause economic or environmental harm. In this paper, we report the identification (from morphology and molecular analysis of COI sequences) of non-indigenous terrestrial flatworms found in a hothouse in Caen (France) as the New Guinea flatworm Platydemus manokwari de Beauchamp, 1963 (Platyhelminthes, Continenticola, Geoplanidae, Rhynchodeminae). Platydemus manokwari is among the “100 World’s Worst Invader Alien Species”. Lists of World geographic records, prey in the field and prey in laboratories of P. manokwari are provided. This species is considered a threat to native snails wherever it is introduced. The recent discovery of P. manokwari in France represents a significant extension of distribution of this Invasive Alien Species from the Indo-Pacific region to Europe. If it escaped the hothouse, the flatworm might survive winters and become established in temperate countries. The existence of this species in France requires an early warning of this incursion to State and European Union authorities, followed by the eradication of the flatworm in its locality, tightening of internal quarantine measures to prevent further spread of the flatworm to and from this site, identifying if possible the likely primary source of the flatworm, and tracing other possible incursions that may have resulted from accidental dispersal of plants and soil from the site.

The impact of the ‘New Zealand flatworm’, Arthurdendyus triangulatus, on earthworm populations in the field

The ‘New Zealand flatworm’, Arthurdendyus triangulatus, is a native of the South Island of New Zealand, which has established in the UK, Ireland and the Faroe Islands. In its introduced range, it is a predator of lumbricid earthworms. To assess the impact of A. triangulatus on earthworm species, flatworm distributions were manipulated into ‘high’, control and ‘low’ densities within a replicated field experiment. Earthworm biomass in the ‘high’ flatworm density treatment was significantly lower than the control or ‘low’ treatments. This was due to a reduction in the anecic species Lumbricus terrestris and, to a lesser extent, Aporrectodea longa. There was little evidence of negative effects on other earthworm species, with even a weakly positive relationship between flatworm density and epigeic biomass. Principal components analysis showed a clear separation of anecic species from A. triangulatus, but the epigeic species Lumbricus festivus and Lumbricus rubellus grouped with A. triangulatus, suggesting that they could be benefitting from reduced intraguild competition. Flatworm densities of 0.8 per m2, comparable to natural infestations in grassland, were predicted to give a reduction in total earthworm biomass of c. 20 %. The bulk of this was comprised of a reduction in anecic species biomass. In particular, it is considered that A. triangulatus poses a serious risk to L. terrestris populations, with implications for soil functioning and indigenous earthworm-feeding wildlife.

The effect of starvation on the planarian Arthurdendyus triangulatus (Tricladida: Terricola) as measured by stable isotopes

Many studies of the population dynamics of the planarian Arthurdendyus triangulatus have been confounded because it has not been possible to define if small flatworms are adults that have been starved or young ones being recruited into the population. Body shrinkage is a process exhibited by planarians under nutritional stress. In birds and the few invertebrate species studied, starvation leads to a 15N-enrichment of body tissues (i.e. an increased δ15N). Under laboratory conditions, the posterior parts of flatworms were removed at day 0 and frozen and compared isotopically with the anterior parts of flatworms, which were starved for 67, 108, 171 and 243 days. With one exception, δ13C 108 days after starvation, the impact of starvation on A. triangulatus %N, %C and δ13C was not significant statistically. In contrast, δ15N increased significantly (to a maximum enrichment of 2.8‰ by day 243) on all sampling dates. This is supported by significant positive correlations between the changes in δ15N between the anterior and posterior body parts and number of days after starvation (p≤0.05) and decrease in body weight (p≤0.01), respectively. Existing δ15N data from field populations of animals show intra-population variability of around 5.0‰, greater than that noted as a result of starvation. Thus, as a single measure, it is unlikely that δ15N can be used to accurately characterise the proportion of starved A. triangulatus within a field population.

A spatio‐temporal analysis of a New Zealand flatworn (Arthurdendyus triangulatus) population in western Scotland

AbstractThe New Zealand flatworm (Arthurdendyus triangulatus), which is an obligate predator of native earthworms, is an alien species to the British Isles and is widely distributed in Scotland. What little is known about its biology under field conditions is mainly from Northern Ireland. Samples taken from single sampling dates have shown A. triangulatus to have an aggregated distribution. To determine the spatio‐temporal distribution of A. triangulatus, a grass field in western Scotland was intensively sampled over a 16‐month period. Data indicate an increase in flatworm numbers and seasonal trends in body weight, the appearance of egg capsules and hatchlings. Results also showed that spatially, the flatworms were aggregated, but this was a transient phenomenon over the period of the experiment. The distribution of egg capsules in the study area was strongly aggregated and related to the appearance of hatchlings. Flatworms may aggregate in areas where soil moisture is optimal for the survival of the New Zealand flatworm.

Reproductive structures of Arthurdendyus triangulatus (Dendy): Seasonality and the effect of starvation

Summary To assess any seasonal changes in the gross morphology of their reproductive structures, Arthurdendyus triangulatus were collected periodically from the field during a period of 1 year and also eight flatworms were starved for between 1 and 11 months. There was no evidence that the occurrence of the reproductive structures was seasonal, with the possible exception of the germaria. The ovaries, testes and sperm ducts of flatworms starved for up to 4 months conformed to those of field-collected flatworms. The first reduction in the reproductive structures of starved flatworms was apparent after 6 months; this reduction took the form of a decrease in the size of the sperm ducts. Although reduced in weight by 75%, A. triangulatus starved for 9 months still retained ovaries, testes and sperm ducts. After 11 months starvation, ovaries, testes and sperm were absent. These results suggest that A. triangulatus can remain reproductively active in the field despite fluctuating prey availability.

Reproductive performance of the New Zealand flatworm Arthurdendyus triangulatus in earthworm species-poor and -rich habitats at Benmore, Scotland

Summary This study of the terrestrial flatworm Arthurdendyus triangulatus at Benmore in Scotland focuses upon egg capsule weight and the number/weight of juveniles within the capsule in relation to food resources available at an earthworm-poor site (botanic garden) and an earthworm-rich site (pastureland). Significant differences in flatworm parameters were evident between sites. In the resource-rich pastureland, egg capsules were heavier and contained more juvenile mass and more individuals, though the weight of the average juvenile in the potential hatchling population was lower. A complex relationship between egg capsule weight, the number of juvenile siblings and their weight was revealed. In general, individual juvenile weight increased with decreasing sibling number and with increasing egg capsule weight. Controlling for these parameters, a higher average individual juvenile weight was found for pastureland. Our study highlights earthworm prey availability as a key factor affecting flatworm reproductive performance.

Invasion of agricultural land by the earthworm predator, Arthurdendyus triangulatus (Dendy)The 7th international symposium on earthworm ecology · Cardiff · Wales · 2002

The ‘New Zealand flatworm’ Arthurdendyus triangulatus is an invasive earthworm predator that is widespread in Northern Ireland. Although this species is most commonly reported from domestic gardens, it is spreading into agricultural grassland. In systematic surveys of grassland fields in Northern Ireland, flatworms were found in 4% (n = 75) in 1991 but 70% (n = 60) in 1998/99. Most flatworms were found under debris at the field margins but in 22% of fields (1998/99) flatworms were recovered from open pasture during formalin expulsion.

Difference in morphometric performance of the New Zealand flatworm Arthurdendyus triangulatus in earthworm species-poor and -rich habitats at Benmore, Scotland

Summary Body weight and egg capsule weight of the terrestrial flatworm Arthurdendyus triangulatus were examined in Benmore Botanic Garden and adjacent pastureland, these respective areas being poor and rich in earthworm species. Flatworms and egg capsules were significantly larger (factor 2–3 and 2, respectively) within pastureland compared with the botanic garden, reflecting lumbricid prey food resources available. Superimposed on this habitat-specific pattern for A. triangulatus was a seasonal trend, individual body weight of both life-stages decreasing from June to September, then increasing by the following April/June. Our study highlights earthworm prey resource variation between sites as a key factor determining the size structure of flatworm populations.

Plant Quarantine as a Measure Against Invasive Alien Species: The Framework of the International Plant Protection Convention and the plant health regulations in the European Union

The introduction of several plant pests into Europe in the 19th century with disastrous consequences called for the development of plant quarantine measures to prevent the spread and introduction of pests of plants and plant products. With the purpose of harmonising these measures, and of promoting measures for pest control, the International Plant Protection Convention (IPPC) was developed to address organisms that are both directly and indirectly injurious to plants. It supplies a framework for measures against invasive alien species according to the Convention on Biological Diversity, as far as they are plant pests. Three examples of invasive alien species within the scope of the IPPC are given in the article: the fungus Ceratocystis fagacearum, the pinewood nematode Bursaphelenchus xylophilus and the flatworm Arthurdendyus triangulatus. In its 1997 revision, the IPPC provides for the establishment of International Standards for Phytosanitary Measures, being acknowledged by the Agreement on the Application of Sanitary and Phytosanitary Measures of the World Trade Organisation. Standards most important for invasive alien species are those on pest risk analysis, on requirements for the establishment of pest-free areas, on surveillance, on pest eradication programmes, and on the import and release of exotic biological agents. Phytosanitary regulations in the European Union (EU) have been harmonised and up to now have regulated about 300 plant pests. The requirements also have a protective horizontal effect against the unintentional introduction of many other species, but the existing broader IPPC mandate for alien plant pests is not fully applied by the EU regulations.

Gene organization and expression of a neuropeptide Y homolog from the land planarian Arthurdendyus triangulatus.

Neuropeptide Y is one of the most widespread regulatory peptides within the vertebrate nervous system and shares the C-terminal motif [FY]-x(3)-[LIVM]-x(2)-Y-x(3)-[LIVMFY]-x-R-x-R-[YF] with pancreatic polypeptide, peptide YY, and fish pancreatic peptide Y. All four peptides are believed to have arisen from a single ancestral gene through successive gene duplication events in vertebrates. The origin of this peptide family may date back further still; similarly sized peptide transmitters with an identical C-terminal motif have been identified in molluscs and flatworms and designated neuropeptide F (NPF). Cloning of the npf gene from the parasitic flatworm Moniezia expansa identified some unusual features within the peptide precursor organization but, at the same time, provided support for an evolutionary relationship of npf and npy genes through the presence of a single intron at a conserved position. To extend the analysis of the evolutionary relationships between invertebrate NPF and vertebrate NPY family peptides, the NPF precursor from the turbellarian Arthurdendyus triangulatus was characterized. Sequence analysis revealed the npf transcript to be 362 base pairs in length encoding a single open reading frame of 81 amino acids. The precursor comprises a signal peptide followed by the mature peptide of 36 amino acids in length, terminating in the typical invertebrate GRPRF motif, followed by a carboxyterminal glycyl extension. The NPF precursor of A. triangulatus shows significant similarities to the vertebrate NPY peptides. Indeed, the N-terminus of A. triangulatus prepro-NPF corresponds more closely to that of the vertebrate peptide homologs than to that of other invertebrate NPFs isolated to date. Immunocytochemical localization studies have demonstrated NPF immunoreactivity throughout the nervous system of A. triangulatus, particularly in association with muscular structures. The data support an early evolutionary origin for this peptide transmitter family within the nervous system of basal bilaterians.

Genetic variation in native and introduced populations of the ‘New Zealand flatworm’, Arthurdendyus triangulatus

SummaryThe internal transcribed spacer regions (ITS1 and ITS2) including the 5.8S region of the ‘New Zealand flatworm’,Arthurdendyus triangulates, are 1004 base pairs in length. Restriction fragment length polymorphism analysis of PCR products (PCR‐RFLP) was conducted onA. triangulatesspecimens from 45 locations in Northern Ireland, Scotland, England and New Zealand. Seven restriction endonucleases(Alu I, Rsa I, Sau3A I, Cfo I, Nde I, Dde I, and Mbo I)were used to reveal intraspecific variation. Analysis of molecular variance revealed the presence of population genetic substructuring, with most genetic heterogeneity present between populations rather than between individuals or geographical regions. No distinct differences were found between Northern Irish and Scottish populations but phylogenetic analysis supports the hypothesis of multiple introductions from New Zealand. There was no significant relationship between genetic distance and geographic distance, as would be expected for natural spread, indicating that this species is largely anthropochorous, even in parts of New Zealand.

The Potential Impact of the New Zealand Flatworm, a Predator of Earthworms, in Western Europe

The New Zealand flatworm Arthurdendyus triangulatus (=Artioposthia triangulata) is an example of an invasive organism that, by reducing lumbricid earthworm populations, could have a major impact on soil ecosystems in Britain and the Faroe Islands. How it was introduced into the British Isles is not known, but like many invasive species, it is suspected that it was introduced by humans and was associated with the trade between New Zealand and Britain. Once established in Britain it found in the large, readily available earthworm population a niche that it could exploit. The microclimate of the forests in the center and south of the South Island of New Zealand from whence the flatworm came is similar to that in parts of the British Isles and consequently conducive to its survival. Although when compared with many other invertebrate introductions (e.g., insects) the flatworm's rate of increase has been slow, a retrospective study strongly suggested that, in Scotland, they spread from botanic gardens to horticultural wholesalers, then to domestic gardens, and only latterly did they invade agricultural land. As with other invasive species, the application of the CLIMEX computer model and geographic-information-system techniques have been used to try to ascertain its potential distribution within both the British Isles and Europe. The data suggest that A. triangulatus could become established in northwest continental Europe, and Denmark, Iceland, and Sweden have added it to their quarantine pest lists. The fact that A. triangulatus is the only one of 12 alien terrestrial planarians in Britain to be considered a pest suggests that this group of invertebrates is behaving in a fashion similar to other invasive organisms and obeys the “tens rule” suggested by M. Williamson. Since within the period 1995–1997 another three species of predatory terrestrial planarians have been recorded in Scotland it is evident that the existing phytosanitary regulations must be more strongly enforced or new ones introduced if the spread of terrestrial planarians is to be halted. For reprints of this Invited Feature, see footnote 1, p. 1259.

THE POTENTIAL IMPACT OF THE NEW ZEALAND FLATWORM, A PREDATOR OF EARTHWORMS, IN WESTERN EUROPE

The New Zealand flatworm Arthurdendyus triangulatus (=Artioposthia triangulata) is an example of an invasive organism that, by reducing lumbricid earthworm populations, could have a major impact on soil ecosystems in Britain and the Faroe Islands. How it was introduced into the British Isles is not known, but like many invasive species, it is suspected that it was introduced by humans and was associated with the trade between New Zealand and Britain. Once established in Britain it found in the large, readily available earthworm population a niche that it could exploit. The microclimate of the forests in the center and south of the South Island of New Zealand from whence the flatworm came is similar to that in parts of the British Isles and consequently conducive to its survival. Although when compared with many other invertebrate introductions (e.g., insects) the flatworm's rate of increase has been slow, a retrospective study strongly suggested that, in Scotland, they spread from botanic gardens to horticultural wholesalers, then to domestic gardens, and only latterly did they invade agricultural land. As with other invasive species, the application of the CLIMEX computer model and geographic-information-system techniques have been used to try to ascertain its potential distribution within both the British Isles and Europe. The data suggest that A. triangulatus could become established in northwest continental Europe, and Denmark, Iceland, and Sweden have added it to their quarantine pest lists. The fact that A. triangulatus is the only one of 12 alien terrestrial planarians in Britain to be considered a pest suggests that this group of invertebrates is behaving in a fashion similar to other invasive organisms and obeys the “tens rule” suggested by M. Williamson. Since within the period 1995–1997 another three species of predatory terrestrial planarians have been recorded in Scotland it is evident that the existing phytosanitary regulations must be more strongly enforced or new ones introduced if the spread of terrestrial planarians is to be halted. For reprints of this Invited Feature, see footnote 1, p. 1259.

The diversity of earthworms in 200 Scottish fields and the possible effect of New Zealand land flatworms (Arthurdendyus triangulatus) on earthworm populations

SummaryEarthworm populations from 200 fields (132 pasture and 68 arable) in Scotland are compared. Earthworms populations from two pasture fields at a Scottish farm infested with the New Zealand terrestrial planarian, Arthurdendyus triangulates (a predator of earthworms), are compared with a subset of these 200 fields (none of which had planarians at the time of the survey). A variety of univariate and multivariate methods are used for comparison. Results from the 200 fields show that the number of individuals, number of species, richness and diversity decline eastwards and northwards across Scotland. There is an overall difference between pasture and arable fields at the same farm, with fewer anecic earthworms (Aporrectodea longa and Lumbricus terrestris), but more Aporrectodea rosea, in arable fields. Conversely, species richness and cumulative species diversity is greater in arable fields, and sample similarity is less. The planarian‐infested fields show differences from the subset of western Scottish pasture fields and from each other. Both have fewer Aporrectodea caliginosa (and endogeic total) and A. longa (and anecic total) than the western pasture fields. One field has fewer L. terrestris and fewer earthworms in total. Univariate factors show no significant differences between the infested fields and similar non‐infested fields, but multivariate analysis suggests differences. Waterlogging and recent growth of rushes in the infested fields are discussed in relation to the reduced population of earthworms and to rainfall.

Import requirements concerning Arthurdendyus triangulatus

EPPO BulletinVolume 31, Issue 1 p. 5-6 Import requirements concerning Arthurdendyus triangulatus First published: 28 June 2008 https://doi.org/10.1111/j.1365-2338.2001.tb00959.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume31, Issue1March 2001Pages 5-6 RelatedInformation

Nursery inspection, exclusion and treatment for Arthurdendyus triangulatus

EPPO BulletinVolume 31, Issue 1 p. 7-10 Free Access Nursery inspection, exclusion and treatment for Arthurdendyus triangulatus First published: 28 June 2008 https://doi.org/10.1111/j.1365-2338.2001.tb00960.xCitations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume31, Issue1March 2001Pages 7-10 RelatedInformation