New Zealand Species Research Articles

Vibrational communication in Scolypopa australis: characterising spontaneous and intrasexual calls in an invasive orchard pest

AbstractVibrational communication in the Auchenorrhyncha is an avenue of growing interest, with many pesticide‐free vibrational pest control programmes against auchenorrhynchan agricultural pests continuing to be developed around the world. Passion vine hoppers (PVH), Scolypopa australis (Walker) (Hemiptera: Ricaniidae), are an economically damaging pest species in New Zealand, where they facilitate the growth of sooty mould in kiwifruit orchards. Scolypopa australis is already known to use vibrational signals, therefore a further understanding of the spectral and temporal characteristics of its calls will be an essential next step to developing vibration‐based pest management strategies. Here, we aimed to characterise the properties of spontaneous S. australis calls in solitary and intrasexual communication contexts. We used laser Doppler vibrometry to record vibrational signals produced by male and female S. australis (separately), when in groups of three or individually. We sorted calls and call sub‐units (syllables) into groups based on cluster analyses of various spatio‐temporal parameters. We define four male calls and three female calls, and newly describe a ‘two‐syllable’ calling structure that may be involved in male intrasexual competition. Certain syllables were more prevalent at the beginning or end of calls for males, and were more homogenously distributed throughout calls for females. The types of calls used differed between single males and groups, with more energetically intense call types observed in the group settings. Additional studies on the behavioural context of S. australis vibrational calls and their responses to playback of such calls will be necessary to assess the viability of vibration‐based pest management for this species.

Population dynamics and prey community of the invasive paper wasp Polistes chinensis (Hymenoptera: Vespidae) in a protected coastal habitat in New Zealand

AbstractThe Asian paper wasp (Polistes chinensis) is an invasive species in New Zealand and a voracious arthropod predator, incorporating a wide range of prey into its diet. We examined the colony survival and prey community composition of these wasps in a protected coastal habitat in New Zealand. Paper wasp colonies at this site were surveyed and monitored weekly over two summers. Our data showed that only ~20% of the monitored colonies each year survived until late summer, with high rates of colony mortality in late spring and early summer. We collected samples of wasp larval guts over a temporal gradient in one nesting season, and via DNA metabarcoding analysis, we identified the prey species consumed. The prey species most frequently identified in larval samples were endemic cicadas and several lepidopteran species. No native arthropod species of known conservation concern were identified in the analysis. However, 63% of the unique taxon sequences retrieved could not be identified by genus or species level, likely due to the absence of reference barcodes. These taxa may represent a group of understudied species, potentially highly endemic or localised. Our analysis indicates that these invasive wasps are opportunistic‐generalist predators with the potential to exert high predation pressure on native arthropods. P. chinensis may be preying on a range of understudied species, especially in remote, natural habitats across New Zealand. We recommend future studies continue to barcode native New Zealand arthropods in order to improve the taxonomic assignments of dietary studies.

International imports and climatic filtering drive compositional variation in non‐native insect establishments

AbstractAimInvasions of non‐native insects can have substantial impacts on agriculture, forestry, human health and biodiversity with considerable economic and environmental consequences. To understand the causes of these invasions, it is important to quantify the relative influence of principal drivers such as international imports and climatic effects.LocationNorth America, Chile, Europe, Australia, New Zealand and Japan.Time Period1881–2020.MethodsTo evaluate the relative contributions of various factors in explaining global variation in numbers of non‐native insect establishments in different world regions, we conducted two multivariate regression analyses to quantify temporal changes in family‐level composition and native ranges of established non‐native species in several world regions.ResultsThere were temporal changes in the family‐level composition of non‐native species assemblages. Prior to 1900, invasions were dominated by scale insects, subsequently shifting to a more diverse set of species, except in North America, which had relatively small compositional change over time compared to other regions. Spatial and temporal variation in the composition of established species was associated with differences in the origin of imports and climatic factors, each explaining 26.3% and 27.4% of the total variation, respectively. The analysis of native ranges of non‐native species indicated that there was no consistent temporal variation across all regions. Established species in New Zealand were predominantly native to Australasia and species in North America and Chile were mainly from Europe. Non‐native species in Europe mainly originated from the Nearctic region while those in Japan and Australia generally originated from multiple regions. Climatic factors in the destination regions had a primary effect (66.3%) on variation in the native range of established species, although imports also had substantial effects (45.4%).Main ConclusionsGeographical variation in climate and imports act together as drivers of establishment success for non‐native insects in all six regions.

New insight into avian malaria vectors in New Zealand

BackgroundMosquitoes (Culicidae) are vectors for most malaria parasites of the Plasmodium species and are required for Plasmodium spp. to complete their life cycle. Despite having 16 species of mosquitoes and the detection of many Plasmodium species in birds, little is known about the role of different mosquito species in the avian malaria life cycle in New Zealand.MethodsIn this study, we used nested polymerase chain reaction (PCR) and real-time PCR to determine Plasmodium spp. prevalence and diversity of mitochondrial cytochrome b gene sequences in wild-caught mosquitoes sampled across ten sites on the North Island of New Zealand during 2012–2014. The mosquitoes were pooled by species and location collected, and the thorax and abdomens were examined separately for Plasmodium spp. DNA. Akaike information criterion (AIC) modeling was used to test whether location, year of sampling, and mosquito species were significant predictors of minimum infection rates (MIR).ResultsWe collected 788 unengorged mosquitoes of six species, both native and introduced. The most frequently caught mosquito species were the introduced Aedes notoscriptus and the native Culex pervigilans. Plasmodium sp DNA was detected in 37% of matched thorax and abdomen pools. When considered separately, 33% of abdomen and 23% of thorax pools tested positive by nested PCR. The MIR of the positive thorax pools from introduced mosquito species was 1.79% for Ae. notoscriptus and 0% for Cx. quinquefasciatus, while the MIR for the positive thorax pools of native mosquito species was 4.9% for Cx. pervigilans and 0% for Opifex fuscus. For the overall MIR, site and mosquito species were significant predictors of Plasmodium overall MIR. Aedes notoscriptus and Cx. pervigilans were positive for malaria DNA in the thorax samples, indicating that they may play a role as avian malaria vectors. Four different Plasmodium lineages (SYAT05, LINN1, GRW6, and a new lineage of P (Haemamoeba) sp. AENOT11) were identified in the pooled samples.ConclusionsThis is the first detection of avian Plasmodium DNA extracted from thoraxes of native Culex and introduced Aedes mosquito species in New Zealand and therefore the first study providing an indication of potential vectors in this country.Graphical

Bioluminescence - The Vibrant Glow of Nature and its Chemical Mechanisms.

Bioluminescence, the mesmerizing natural phenomenon where living organisms produce light through chemical reactions, has long captivated scientists and laypersons alike, offering a rich tapestry of insights into biological function, ecology, evolution as well as the underlying chemistry. This comprehensive introductory review systematically explores the phenomenon of bioluminescence, addressing its historical context, geographic dispersion, and ecological significance with a focus on their chemical mechanisms. Our examination begins with terrestrial bioluminescence, discussing organisms from different habitats. We analyze thefireflies of Central Europe's meadows and the fungi in the Atlantic rainforest of Brazil. Additionally, we inspect bioluminescent species in New Zealand, specifically river-dwelling snails and mosquito larvae found in Waitomo Caves. Our exploration concludes in the Siberian Steppes, highlighting the area's luminescent insects and annelids. Transitioning to the marine realm, the second part of this review examines marine bioluminescent organisms. We explore this phenomenon in deep-sea jellyfish and their role in the ecosystem. We then move to Toyama Bay, Japan, where seasonal bioluminescence of dinoflagellates and ostracods present a unique case study. We also delve into the bacterial world, discussing how bioluminescent bacteria contribute to symbiotic relationships. For each organism, we contextualize its bioluminescence, providing details about its discovery, ecological function, and geographical distribution. A special focus lies on the examination of the underlying chemical mechanisms that enables these biological light displays. Concluding this review, we present a series of practical bioluminescence and chemiluminescence experiments, providing a resource for educational demonstrations and student research projects. Our goal with this review is to provide a summary of bioluminescence across the diverse ecological contexts, contributing to the broader understanding of this unique biological phenomenon and its chemical mechanisms serving researchers new to the field, educators and students alike.

Step-point sampling for broadleaved species’ ground cover estimation in pastures – an evaluation of Cockayne’s point on a boot toecap method

ABSTRACT Step-point sampling, conceived by plant ecologist Dr Leonard Cockayne in ca. 1925 as a method for measuring the ground cover of species in New Zealand’s modified tussock grasslands utilises a point marked on the observer’s boot toecap. It is resource-efficient compared to other vegetation sampling methods and here we report on a unique evaluation of its accuracy and precision. The estimated cover of Taraxacum officinale in a grassy field (11%) was not significantly different from that obtained using line-point sampling (13%), but higher than that from line-intercept sampling (5.7%). It was unaffected across an order-of-magnitude range of sampling intensity (1600 to 160 observations/ha) and was acceptably precise with ≥ 400 observations/ha, although increased linearly with observation point size. These empirical results were supported by computer simulations enabling both accuracy and precision to be evaluated along with plant architecture. The simulations indicated that step-point sampling with ca. 400 observations per ha and an observation point diameter ≤ 1.1 cm (1.0 cm2), can provide ground cover estimates for a wide range of broadleaved species in pastures that are sufficiently accurate and precise for common pasture management applications. The method is deployed in the phone application, ‘Grassland Cover Estimator’ available at https://www.agresearch.co.nz/search?q = Grassland + cover + estimator.

Description and molecular data of a new cestode parasite, Cladotaenia anomala n. sp. (Paruterinidae) from the Australasian harrier (Circus approximans Peale) in New Zealand

Currently comprising 12 species infecting the gastrointestinal tracts of diurnal raptors (Falconiformes, Accipitriformes), species of Cladotaenia are diagnosed by their branching uterus, testes in two fields reaching the same level anteriorly, and small rostellum armed with taenioid hooks arranged in two rows. In this study we describe a new species of Cladotaenia recovered from a number of Australasian harriers Circus approximans, from the southern half of South Island, New Zealand. The new species is distinguished from other species by its single circle of hooks. It is closest, morphologically, to C. circi, but differs in the shape of the terminal proglottids and the number of uterine branches. Sequences of 28S and cox1 gene are presented. Genetically, Cladotaenia anomalan. sp. is closest to Cladotaenia globifera but differs morphologically in the size of the suckers, testes and eggs. This description constitutes the first record of a Cladotaenia species in New Zealand. We discuss some potential routes this parasite may have taken to arrive in New Zealand.

Morphometric and meristic discrimination within juvenile flounder species in New Zealand indicate genetic and environmental disparities

ABSTRACT Morphometrics and meristics are measurable and countable traits, respectively, that are under simultaneous control by genetic and/or environmental factors. Resolving morphometric and meristic spatial variation can be a useful technique for identifying population structure and connectivity. The present study investigated morphometric and meristic character variation within three flounder species, sand flounder (Rhombosolea plebeia), greenback flounder (R. tapirina), and yellowbelly flounder (R. leporina) in New Zealand, predominantly in the South Island. Four morphometric measurements and two meristic characters were obtained from 857 juvenile flounder, standardised, and analysed. Consistent with a previous genetic analysis, the differentiation of morphometric and meristic characters supported the idea that sand flounder populations north and south of 42o S were reproductively isolated, and although statistically non-significant, there was an indication that yellowbelly flounder collected from Lake Ellesmere and Orowaiti Lagoon may have been reproductively isolated. Only juvenile sand flounder and greenback flounder were collected in the tidal reaches of estuaries throughout east Otago and the populations are considered undifferentiated based on intra-species morphometric and meristic characters. Our results demonstrated that the influence of environmental variation and adaptive physiology of juvenile flounder likely contributed to the morphometric and meristic variation of individuals among estuaries and years.

New records of Phytoseiidae (Acari: Mesostigmata) in New Zealand, with notes on the occurrence status of some species</p >

This study contributes to the extensive history of research on the family Phytoseiidae in New Zealand, covering nearly a century. We examined phytoseiid specimens in the major repositories, unveiling fifteen species new to New Zealand: Amblyseius andersoni (Chant), A. waltersi Schicha, A. williamsi Schicha, Australiseiulus australicus (Womersley), Euseius elinae (Schicha), Graminaseius graminis (Chant), G. sturti (Schicha), Neoseiulus alpinus (Schweizer), N. californicus (McGregor), N. dieteri (Schicha), N. tareensis (Schicha), Proprioseiopsis anthurii (Schicha), P. cabonus Schicha & Elshafie, P. okanagensis (Chant) and Typhlodromus transvaalensis (Nesbitt), and clarifying the presence or absence status of some species in the country. Additionally, we analysed the diversity and distribution of species in New Zealand, presenting an updated checklist of phytoseiid species in the country.

A new deep-sea Cristaphyes (Kinorhyncha: Allomalorhagida: Pycnophyidae) from the continental rise of South Island, New Zealand

ABSTRACT A new kinorhynch species, Cristaphyes microtubuliferus sp. nov., is described from the continental rise of South Island, New Zealand. The new species is recognised by the presence of very poorly developed lateral terminal spines, combined with its considerable trunk length, which can exceed 1 mm. In addition, the new species is characterised by morphologically dimorphic setae, i.e. the regular long and slender setae found in most pycnophyid species, and much shorter and more rigid ‘minute setae’. Besides the new species, the presence of two additional undescribed Cristaphyes species is reported. The material is insufficient to support formal species descriptions for the latter two, but short diagnoses are provided for the species. The description of Cristaphyes microtubuliferus sp. nov. brings the total number of described and identified kinorhynch species in New Zealand up to 19. With the new species included, the genus Cristaphyes now accommodates 26 species, of which only six are known from the southern hemisphere. LSID: urn:lsid:zoobank.org:pub: 77FEA91A-7684-4664-9DFC-470A245D9267

Flexibility in reproductive attributes may facilitate the invasive capacity of the Mediterranean fanworm, Sabella spallanzanii (Gmelin)

Context The Mediterranean fanworm arrived as a non-indigenous species in parts of Australasia, where it has established and then rapidly spread from the initial points of arrival, despite marked differences in environmental conditions compared from its natal habitat in the Mediterranean Sea. Aims To better understand the invasive capacity of this species in New Zealand. Methods Maturation, reproductive cycle, and gametogenesis were investigated, with a focus on female gamete development, for a population in Auckland, and the results were compared with those of previous studies in the Mediterranean Sea and Australia. Key results Egg sizes in female fanworms were highly variable throughout the year; however, a reduced presence of larger eggs was observed from August to November, which could indicate spawning. This Auckland fanworm population also appeared to have a female-skewed sex ratio compared with previous studies where a 1:1 sex ratio was observed. Fanworm maturation was reached at ~6 cm in length, compared with 15 cm in natal populations. Fanworms with body size smaller than 5 cm were not mature and did not produce mature gametes, in contrast to an Australian fanworm population. Conclusions The observed Mediterranean fanworm population in New Zealand demonstrates reproductive flexibility and high fecundity, contributing to its invasive capacity. Implications The reproductive biology of a species is important in determining its invasive capacity, and may also be flexible between populations, with implications for effective biosecurity management strategies.

Physiological responses of Caulerpa spp. (with different dissolved inorganic carbon physiologies) to ocean acidification

ABSTRACT Caulerpa is a widely distributed genus of chlorophytes (green macroalgae) which are important for their dietary, social and coastal ecosystem value. Ocean acidification (OA) threatens the future of marine ecosystems, favouring macroalgal species that could benefit from increased seawater carbon dioxide (CO2) concentrations. Most macroalgae species possess CO2 concentrating mechanisms (CCMs) that allow active uptake of bicarbonate (HCO3 −). Those species without CCMs are restricted to using CO2, which is currently the least abundant species of dissolved inorganic carbon (DIC) in seawater. Thus, macroalgae without CCMs are predicted to be likely benefit from OA. Caulerpa is one of the rare few genera that have species both with and without CCMs. The two most common Caulerpa species in New Zealand are C. geminata (possesses a CCM) and C. brownii (non-CCM). We investigated the responses of growth, photo-physiology and DIC utilisation of C. geminata and C. brownii to four mean seawater pH treatments (8.03, 7.93, 7.83 and 7.63) that correspond to changes in pH driven by increases in pCO2 simulating future OA. There was a tendency for the mean growth rates for C. brownii (non-CCM) to increase under lower pH, and the growth rates of C. geminata (CCM) to decline with lower pH, although this was not statistically significant. However, this is likely because variability in growth rates also increased as seawater pH declined. There were few other differences in physiology of both species with pH, although there was tendency for greater preference for CO2 over HCO3 − uptake in the CCM species with declining seawater pH. This study demonstrates that DIC-use alone does not predict macroalgal responses to OA.

First records of two mackerel shark species (Carcharodon planus comb. nov. and Carcharodon hubbelli; Lamnidae) from New Zealand

ABSTRACTThe fossil record of the genus Carcharodon (Lamniformes: Lamnidae) dates to the late Oligocene and has a near global distribution. Today the genus is represented by a single species, the white shark Carcharodon carcharias. However, multiple extinct species are recognised in the Cenozoic including Carcharodon hastalis, Carcharodon hubbelli and Carcharodon planus comb. nov. Here we present the first occurrences of Carcharodon hubbelli and Carcharodon planus from New Zealand/Aotearoa, from the South Island/Te Waipounamu. Carcharodon hubbelli is previously reported from late Miocene deposits in the Pacific basin of North and South America, Asia, and Australia. Whereas Carcharodon planus has been reported from the Miocene of North America and Asia. One tooth from Carcharodon hubbelli is reported from the presumed late Miocene of Motunau Beach, North Canterbury, while one upper early Miocene tooth recovered from the Kakahu River, South Canterbury and an earliest Miocene tooth from the Big River mouth, Tasman District are referred to Carcharodon planus. In addition to being the first reported occurrences of these two species in New Zealand, the teeth of Carcharodon planus represent some of the earliest occurrences of the taxon as well as its southernmost occurrence.

New marine species in New Zealand – an institutional snapshot

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Range reshuffling: Climate change, invasive species, and the case of Nothofagus forests in Aotearoa New Zealand

AbstractAimThe impact of climate change on forest biodiversity and ecosystem services will be partly determined by the relative fortunes of invasive and native forest trees under future conditions. Aotearoa New Zealand has high conservation value native forests and one of the world's worst invasive tree problems. We assess the relative effects of habitat redistribution on native Nothofagus and invasive conifer (Pinaceae) species in New Zealand as a case study on the compounding impacts of climate change and tree invasions.LocationAotearoa New Zealand.MethodsWe use species distribution models (SDMs) to predict the current and future distribution of habitat for five native Nothofagus species and 13 invasive conifer species under two 2070 climate scenarios. We calculate habitat loss/gain for all species and examine overlap between the invasive and native species now and in future.ResultsMost species will lose habitat overall. The native species saw large changes in the distribution of habitat with extensive losses in North Island and gains mostly in South Island. Concerningly, we found that most new habitat for Nothofagus was also suitable for at least one invasive species. However, there were refugia for the native species in the wetter parts of the climate space.Main ConclusionIf the predicted changes in habitat distribution translate to shifts in forest distribution, it would cause widespread ecological disruption. We discuss how acclimation, adaptation and biotic interactions may prevent/delay some changes. But we also highlight that the poor establishment capacity of Nothofagus, and the contrasting ability of the conifers to invade, will present persistent conservation challenges in areas of both new habitat and forest retreat. Pinaceae are problematic invaders globally, and our results highlight that control of invasions and active native forest restoration will likely be key to managing forest biodiversity under future climates.

Boring bryozoans: an investigation into the endolithic bryozoan family Penetrantiidae

An endolithic lifestyle in mineralized substrates has evolved multiple times in various phyla including Bryozoa. The family Penetrantiidae includes one genus with ten extant and two fossil species. They predominantly colonize the shells of molluscs and establish colonies by chemical dissolution of calcium carbonate. Based on several morphological characters, they were described to be either cheilostome or ctenostome bryozoans. For more than 40 years, neither the characters of species identity and systematics nor the problem of their phylogeny was approached. Consequently, the aim of this study is to reevaluate species identities and the systematic position of the genus Penetrantia by analyzing at least six different species from eight regions with the aid of modern methods such as confocal laser scanning microscopy and 3D-reconstruction techniques. This study demonstrates that the musculature associated with the operculum and brood chamber shows significant differences from the cheilostome counterparts and seems to have evolved independently. Together with the presence of other ctenostome-like features such as true polymorphic stolons and uncalcified body wall, this finding supports a ctenostome affinity. Operculum morphology reveals many new species-specific characters, which, together with information about gonozooid morphology, tentacle number, and zooid size ranges, will enhance species identification. It also revealed a probable new species in Japan as well as potential cryptic species in France and New Zealand. In addition, this study increases the known distribution range of the family and its substrate diversity. Altogether, the new information collated here provides the basis for future work on a neglected taxon.

Species distribution and susceptibility of Nocardia isolates in New Zealand 2002–2021

The aim was to record the distribution and susceptibility of Nocardia species in New Zealand. Local and referred isolates were identified by an evolving approach over the study period including conventional phenotypic methods, susceptibility profiles, matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF) and molecular sequencing. Isolates previously identified as a Nocardia sp. or part of the N.asteroides complex were reidentified by MALDI-TOF and/or molecular methods. Antimicrobial susceptibility to eight antibiotics was performed by standard microbroth dilution. The site of isolation, susceptibility profiles and species distribution were analysed. A total of 383 isolates were tested: N.brasiliensis 23 (6%), N.cyriacigeorgica 42 (11%), N.farcinica 41 (11%), N.nova complex 226 (59%), and 51 (13%) other species/complexes. The respiratory tract was the most common site of infection (244, 64%), with skin and soft tissue the second most common site (104, 27%). All 23 N.brasiliensis isolates were from skin and soft tissue specimens. Almost all isolates (≥98%) were susceptible to amikacin, linezolid and trimethoprim-sulfamethoxazole; 35% and 77% were resistant to clarithromycin and quinolones, respectively. The expected susceptibility profiles of the four common species and complex were observed for most agent-organism parings. Multi-drug resistance was uncommon (3.4%). The spectrum of Nocardia species in New Zealand is similar to overseas reports and our most common group is the N.nova complex. While amikacin, linezolid and trimethoprim-sulfamethoxazole remain good empiric treatment choices, other agents should have their activity confirmed before use.

The role of ion homeostasis imbalance due to citrate accumulation in fluoroacetic acid (FAA) toxicity in Neurospora crassa

Fluoroacetic acid (FAA) is a poison commonly used for the lethal control of invasive species in Australia and New Zealand. Despite its widespread use and long history as a pesticide, no effective treatment for accidental poisoning exists. Although it is known to inhibit the tricarboxylic acid (TCA) cycle, specific details of FAA toxicology have remained elusive, with hypocalcemia suggested to be involved in the neurological symptoms prior to death. Here, we study the effects of FAA on cell growth and mitochondrial function using the filamentous fungi Neurospora crassa as model organism. FAA toxicosis in N. crassa is characterized by an initial hyperpolarization and subsequent depolarization of the mitochondrial membranes, followed by a significant intracellular decrease in ATP and increase in Ca2+. The development of mycelium was markedly affected within 6 h, and growth impaired after 24 h of FAA exposure. Although the activity of mitochondrial complexes I, II and IV was impaired, the activity of citrate synthase was not affected. Supplementation with Ca2+ exacerbated the effects of FAA in cell growth and membrane potential. Our findings suggest that an imbalance created in the ratio of ions within the mitochondria may lead to conformational changes in ATP synthase dimers due to mitochondrial Ca2+ uptake, that ultimately result in the opening of the mitochondrial permeability transition pore (MPTP), a decrease in membrane potential, and cell death. Our findings suggest new approaches for the treatment research, as well as the possibility to use N. crassa as a high-throughput screening assay to evaluate a large number of FAA antidote candidates.

Root diameter, host specificity and arbuscular mycorrhizal fungal community composition among native and exotic plant species.

Plant root systems rely on a functionally diverse range of arbuscular mycorrhizal fungi to, among other benefits, extend their nutrient foraging. Extended nutrient foraging is likely of greatest importance to coarse-rooted plants, yet few studies have examined the link between root traits and arbuscular mycorrhizal fungal community composition. Here, we examine the relationship between root diameter and the composition of arbuscular mycorrhizal fungal communities in a range of native and exotic plant species. We characterized the arbuscular mycorrhizal fungal communities of 30 co-occurring native and exotic montane grassland/shrubland plant species in New Zealand. We found that plant root diameter and native/exotic status both strongly correlated with arbuscular mycorrhizal fungal community composition. Coarse-rooted plants had a lower diversity of mycorrhizal fungi compared with fine-rooted plants and associated less with generalist fungal partners. Exotic plants had a lower diversity of fungi and fewer associations with nondominant families of arbuscular mycorrhizal fungi compared with native plants. These observational patterns suggest that plants may differentially associate with fungal partners based on their root traits, with coarse-rooted plants being more specific in their associations. Furthermore, exotic plants may associate with dominant arbuscular mycorrhizal fungal taxa as a strategy in invasion.

Taxonomic revision of Tinocladia (Ectocarpales s.l., Phaeophyceae): merger of Tinocladia with Eudesme and description of E. pseudocrassa sp. nov

ABSTRACT A molecular phylogeny of Tinocladia and Eudesme based on specimens covering a large proportion of the known species was done using mitochondrial cox1 and cox3, chloroplast atpB, psaA, psbA and rbcL genes and 5.8S rDNA and its ITS2 region sequences. The phylogeny revealed a close phylogenetic relationship between the two genera and the occurrence of a cryptic species within the generitype T. crassa. Eudesme species (E. borealis, E. shandongensis and the generitype E. virescens) showed a sister relationship with the northern hemisphere Tinocladia (T. crassa, including a cryptic sister species T. pseudocrassa sp. nov., and T. sanrikuensis), whereas southern hemisphere Tinocladia (T. australis, T. falklandica, T. novae-zelandiae, and a cryptic species from New Zealand) nested in the Eudesme clade. Morphologically, Tinocladia species have been distinguished from Eudesme by their denser medullary filaments and more extensive subcortical layer, but our molecular phylogenetic analyses suggest that these features do not correlate with genetic differences. The cox3 sequence divergence between northern hemisphere Tinocladia and the lineage that includes Eudesme and southern hemisphere Tinocladia was comparable to or smaller than those within selected ectocarpalean genera. We therefore propose to merge Tinocladia with Eudesme and resurrect Eudesme crassa (Suringar) Okamura for T. crassa. Although the two independent lineages of T. crassa do not show marked morphological differences, they are genetically isolated even in sympatric populations. We therefore propose to treat them as independent species. In this paper we neotypify Tinocladia crassa (=Eudesme crassa), describe E. pseudocrassa sp. nov., and determine that the Californian population of E. crassa is an introduction from Northeast Asia. HIGHLIGHTS •A taxonomic revision of Eudesme and Tinocladia, based on genetic and morpho-anatomy, provides evidence to merge Tinocladia with Eudesme. •The finding of cryptic species in New Zealand highlights the need for further taxonomic studies in this region. •The genetic data have revealed the occurrence of a cryptic species within T. crassa in Japan.