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Host-microbe interactions are ubiquitous and play important roles in host biology, ecology, and evolution. Yet, host-microbe research has focused on inland species, whereas marine hosts and their associated microbes remain largely unexplored, especially in developing countries in the Southern Hemisphere. Here, we review the current knowledge of marine host microbiomes in the Southern Hemisphere. Our results revealed important biases in marine host species sampling for studies conducted in the Southern Hemisphere, where sponges and marine mammals have received the greatest attention. Sponge-associated microbes vary greatly across geographic regions and species. Nevertheless, besides taxonomic heterogeneity, sponge microbiomes have functional consistency, whereas geography and aging are important drivers of marine mammal microbiomes. Seabird and macroalgal microbiomes in the Southern Hemisphere were also common. Most seabird microbiome has focused on feces, whereas macroalgal microbiome has focused on the epibiotic community. Important drivers of seabird fecal microbiome are aging, sex, and species-specific factors. In contrast, host-derived deterministic factors drive the macroalgal epibiotic microbiome, in a process known as "microbial gardening". In turn, marine invertebrates (especially crustaceans) and fish microbiomes have received less attention in the Southern Hemisphere. In general, the predominant approach to study host marine microbiomes has been the sequencing of the 16S rRNA gene. Interestingly, there are some marine holobiont studies (i.e., studies that simultaneously analyze host (e.g., genomics, transcriptomics) and microbiome (e.g., 16S rRNA gene, metagenome) traits), but only in some marine invertebrates and macroalgae from Africa and Australia. Finally, we introduce an ongoing project on the surface microbiome of key species in the Strait of Magellan. This is an international project that will provide novel microbiome information of several species in the Strait of Magellan. In the short-term, the project will improve our knowledge about microbial diversity in the region, while long-term potential benefits include the use of these data to assess host-microbial responses to the Anthropocene derived climate change. [ABSTRACT FROM AUTHOR]

The sublethal effects of infectious disease on reproductive behaviour and mating success are not well understood. Here, we investigated predictors of male mating success in one of Australia's most critically endangered vertebrates: the northern corroboree frog, Pseudophryne pengilleyi. Using a genomic approach to assign parentage, we explored whether infection with the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), a pathogen responsible for amphibian declines globally, influenced male calling behaviour and mating success. We also explored whether male mating success was predicted by phenotypic traits (age, body size, coloration, call characters) that potentially signal genetic quality, and the soil moisture (water potential) of male-constructed terrestrial nests, which may directly impact offspring survival. We found that Bd significantly influenced male advertisement; Bd -infected males produced calls with significantly higher pulse repetition rates than uninfected males. Older males had a higher probability of mating; however, variation in the number of eggs in a nest was most strongly explained by an interaction between male Bd infection status and call pulse repetition rate. We propose that these relationships may result from either pathogen-mediated changes to host behaviour or host-mediated changes to behaviour (e.g. terminal investment). Regardless of the mechanism, this is the first evidence that male mating success in an amphibian can be influenced by male Bd infection status, highlighting a novel mechanism through which this virulent pathogen can affect amphibian fitness. More broadly, these findings add to a growing body of evidence that pathogens can alter the reproductive biology of their hosts. From a conservation perspective, increased consideration of how sexual selection operates in altered environments has the potential to assist with the management of threatened amphibians worldwide. • We studied the effect of chytrid infection on male mating success in corroboree frogs. • Chytrid infection influenced male calling and the number of eggs in a male's nest. • Male age also influenced mating success. • We show for the first time that disease can alter amphibian mating outcomes. [ABSTRACT FROM AUTHOR]

Wolbachia are intracellular bacteria that infect a wide range of arthropod and nematode hosts, whose reproduction they manipulate to increase rates of vertical transmission. Horizontal transmission between unrelated species also occurs; pathways and mechanisms are still under debate, but parasitoid wasps have been suggested as potential vectors. Here, we perform the largest screening of Wolbachia in any parasitoid group by sampling 228 species of Ichneumonidae from Australia. The observed infection frequency of 23% is very close to the proposed global equilibrium frequency of ~20%. Rates of gain and loss are very similar in comparisons between different parasitoid lifestyles, such as ecto- vs. endoparasitoids. Genotyping Wolbachia showed identical strains in several unrelated ichneumonid species and other insect groups from around the world. A permutation test comparing Wolbachia strains in parasitoids and their host orders did not yield conclusive results, nor did a test for a latitudinal gradient. We argue that future studies should carefully consider the time scale of the processes under investigation. The speed at which Wolbachia move horizontally is probably so high that potential patterns are quickly erased and cannot be detected when sampling at the species level, nor with the slowly evolving multilocus sequence typing set of bacterial markers. [ABSTRACT FROM AUTHOR]

Background: Biancolina Della Valle (Monograpie 20:1893) are minute amphipods that bore tunnels into algal tissue. Their global distribution and diversity are poorly known due to their small size and concealed habit. Results: Biancolina japonica Ishimaru (J Crust Biol 16:395-405, 1996) is reported from Bare Island, Botany Bay, New South Wales, Australia and is only the second species of Biancolina recorded in Australian waters following B. australis Nicholls (Rec South Aust Mus 6:309-334, 1939). B. japonica is found exclusively on species of Sargassum where it burrows into algal tissues to feed. Conclusions: We report Biancolina japonica Ishimaru (J Crust Biol 16:395-405, 1996), previously known only from Japan, for the first time in Australian waters. A review of the known algal hosts of all eight species of Biancolina indicates high levels of feeding specialisation on brown algae from the order Fucales. [ABSTRACT FROM AUTHOR]

Pinworm nematodes of the genus Syphacia (Nemata : Oxyurida : Oxyuridae) have a global distribution, and infect the caecum of rodents. Within the Australian Bioregion, 17 species of Syphacia infect a range of rodent hosts. Pinworms are traditionally thought to have coevolutionary relationships with their hosts, but the evolution and dispersal of Australian rodents and their helminths remains unclear. This combination of factors allowed us to investigate the likely relationships of Australian Syphacia species based on phylogenetic analysis, overlaid with the ecology and relationships of host species. We conducted a phylogenetic analysis using morphological characters of the species of Syphacia from the Australian Bioregion in order to examine the relationships between species, and to investigate how host evolution and phylogeny could inform (or be informed) by parasite phylogeny. Application of the taxon pulse theory of parasite speciation by matching host species to parasites shed some light on the timing of speciation of rodent hosts. We found that species of Syphacia had reasonably close host-parasite relationships, with additional evidence for ecological fitting or host switching occurring. Evidence provided here suggests strongly that most elements of the Stockholm Paradigm are at play in structuring the relationships we observe in this pinworm-mammal system. [ABSTRACT FROM AUTHOR]

Thaumastocoris peregrinus is a sap-feeding insect native to Australia that has become a serious global pest of Eucalyptus species. To date, T. peregrinus has been found in more than 10 countries across Europe, Africa, South America and Oceania., In the present study, we used the climate modelling software climex (Hearne Scientific Software Pty Ltd, Australia) to predict the potential distribution of T. peregrinus globally and in New Zealand. climex parameters were based on experimental data obtained in the present study and from records collated from the insect's native and invasive distribution., The model of the potential native geographical distribution closely agrees with the known distribution of T. peregrinus and predicts potential expansion into more tropical areas of Australia. In New Zealand, the predicted potential distribution of T. peregrinus matches its current distribution and predicts that, if a suitable host is present, the species will be able to establish in most of the North Island and in northern and eastern regions of the South Island., Globally, the model predicts that many of the world's temperate, Mediterranean and subtropical areas are climatically suitable for establishment of T. peregrinus. This predicted distribution closely matches the global distribution of eucalypt plantations, which are essential for the establishment of this pest., climex projections of potential suitability for T. peregrinus reported in the present study may prove useful for risk assessments and for the identification of areas susceptible to invasion by this pest. [ABSTRACT FROM AUTHOR]

Aim Invasive Acacia species have negatively impacted natural areas in multiple regions around the globe. Almost 400 Acacia species have been introduced outside their native ranges in Australia; approximately 6% have become invasive, 12% are naturalized, and 82% have no record of naturalization or invasion. This variation in invasiveness provides a comparative framework in which to examine mechanisms that either promote or constrain establishment and colonization of species in novel regions. Here, we experimentally examine the role that the legume-rhizobia symbiosis plays in the differential invasiveness of acacias introduced outside their native Australian ranges. Location Canberra, Australia. Methods We paired 12 Acacia species ranging in invasiveness globally with 12 rhizobial strains ranging in average symbiotic effectiveness. We measured plant growth and nodulation success and abundance to assess whether invasive acacias were more promiscuous hosts, that is had positive growth and nodulation responses to a broader range of rhizobial strains than naturalized and non-invasive species. Results Invasive acacias had a higher growth response across more rhizobial strains (six of 12 strains) than naturalized and non-invasive species, but invasiveness categories differed only moderately with regard to the percentage of plants with nodules and nodulation abundance. Main conclusion With respect to plant growth, invasive acacias appear to be more promiscuous hosts than naturalized and non-invasive Australian Acacia species. Plant growth response to nodulation, however, is likely more important than nodulation alone in the successful invasion of species in novel ranges. Results from this study help elucidate an important mechanism in the invasive capacity of legumes. [ABSTRACT FROM AUTHOR]

A new opecoelid cercaria, Cercaria capricornia XII, is reported from Nassarius olivaceus in Capricornia, Central Queensland, Australia. Combined molecular and morphological data indicate that this cercaria is a member of the subfamily Opecoelinae. Cercaria capricornia XII is the first known opecoeline cercaria reported from a nassariid gastropod. Cercaria capricornia XII can be distinguished from other opecoelid cercariae by the combination of the presence of a 2-pointed stylet, body length and width, and the size of the tail. The emergence pattern for C. capricornia XII in captivity was erratic; rapid emergences of thousands of cercariae were interspersed by periods that sometimes exceeded a month in which no emergence occurred. There was no detectable pattern to or stimulus of the emergence. The molluscan host range of opecoelids is analysed in detail. Gastropods from the Buccinoidea, Cerithioidea and Rissooidea are hosts to both opecoeline and plagioporine cercariae, but the dominant subfamily infecting the Cerithioidea and Rissooidea is the Plagioporinae. The dominant marine host gastropod superfamily for opecoeline cercariae is the Buccinoidea; the family Nassariidae is contained in the Buccinoidea. The range of gastropod superfamilies known as hosts of plagioporines is much broader than that for opecoelines, which may be explained by the relative size of the two opecoelid families and perhaps by indications that the Plagioporinae is polyphyletic. [ABSTRACT FROM AUTHOR]

The Australian members of the spider wasp genus Agenioideus are revised, and its two constituent species, Agenioideus expulsus Turner and A. nigricornis (Fabricius), are redescribed. A third species, Agenioideus ultimus (Turner), is transferred to Spuridiophorus Arnold, a genus that is newly recorded here from the Australian continent. Diagnoses and criteria to facilitate the identification of the two genera are provided, along with information on the distribution and host biology of Agenioideus species. The first records of a pompilid utilising Latrodectus hasselti Thorell (redback spider) as a host at multiple locations across southern Australia are presented, along with a brief synopsis of insect parasitoids and predators of L. hasselti in Australia. [ABSTRACT FROM AUTHOR]

The coral gall crab Pseudocryptochirus viridis is an obligate symbiont of some species of the Indo-West Pacific coral genus Turbinaria. The colour pattern variation within the species is illustrated for the first time. Overviews of the coral host species and distribution records are provided, including new records from Indonesia, Malaysia and Australia. [ABSTRACT FROM AUTHOR]

Abstract: The use of visual and chemical cues in host detection is regarded as important but relatively unknown for many symbionts. The small circumtropical caridean shrimp Gnathophylloides mineri forms a close symbiotic association with sea urchins, particularly Tripneustes gratilla, in many parts of the world. G. mineri is known to occur in temperate eastern Australia but the breadth of host use and selection of hosts amongst different species of sea urchins is relatively unknown. The abundance of G. mineri on three co-occurring species of sea urchins, T. gratilla, Heliocidaris tuberculata and Pseudoboletia indiana were measured in eastern Australia. These species of sea urchins were chosen because of either a known prior association with this shrimp elsewhere in the world, or due to their abundance in the area in temperate Australia where the shrimp occurs. Field collections showed that the association between shrimp and sea urchin appears extremely host-specific, with G. mineri only observed on T. gratilla, at an average density of two shrimp per sea urchin. Moreover, the majority of symbionts occurred on the underside (oral region) of T. gratilla. A visual laboratory experiment showed that G. mineri would actively move towards T. gratilla in preference to the other potential host species in the absence of chemical signals. Using a Y-maze, we tested the reaction of G. mineri to the absence of visual signals but the presence of chemical signals originating from their host, and from other species of potential host sea urchins. Seawater alone was used as a negative control. We demonstrated that G. mineri could detect T. gratilla from a distance, the same host that the shrimp are associated with in the field, using visual and chemical cues. Moreover, G. mineri react quickly to visual and chemical host signals by moving towards T. gratilla in preference to other species of sea urchins or in the absence of a signal. The relative importance of visual versus chemical cues is, however, unknown. [Copyright &y& Elsevier]

Abstract: A variety of Bartonella species were detected in two species of ticks and three species of fleas collected from marsupial hosts; brush-tailed bettong or woylie (Bettongia penicillata) and western barred bandicoots (Perameles bougainville) and from a rodent host; Rattus fuscipes in Western Australia. Bartonella species were detected using nested-PCR of the gltA gene and the 16S–23S ribosomal internal transcribed spacer region (ITS), and species were characterized using DNA sequencing of the 16S rRNA, gltA, rpoB, ftsZ genes and the ITS region. Bartonella rattaustraliani and B. coopersplainsensis were detected in Ixodes spp. ticks and fleas (Stephanocircus pectinipes) respectively collected from rodents. Two novel Bartonella species were detected from marsupials; Candidatus Bartonella woyliei n. sp. was detected in both fleas (Pygiopsylla hilli) and ticks (Ixodes australiensis) collected from woylies and Candidatus Bartonella bandicootii n. sp. was detected in fleas (Pygiopsylla tunneyi) collected from western barred bandicoots. Concatenated phylogenetic analysis of all 5 loci clarified the marsupial cluster of Bartonella species in Australia and confirmed the species status of these two Bartonella species in ticks and fleas from woylies and western barred bandicoots, which are classified as threatened species and are vulnerable to extinction. [Copyright &y& Elsevier]

Aims To highlight the increasing importance of pests and pathogens to Australian Acacia species, where they are planted as non-natives in commercial plantations and in their native environment. Location Africa, Asia, Australia, South America. Methods Existing literature and results of unpublished surveys on pests and pathogens of Australian acacias are reviewed. These are discussed within the context of a growing importance of invasive alien insects and pathogens including novel encounters and host jumps. Results Australian acacias planted as non-natives in various parts of the world are increasingly threatened by pests and pathogens. These include those that are accidentally being introduced into the new environments as well as 'new encounter' pests and pathogens that are undergoing host shifts to infect non-native acacias. Furthermore, insects and pathogens for biological control of invasive Australian acacias present substantial challenges for plantation forestry. Main conclusions Pests and pathogens will seriously challenge plantation forestry based on non-native Australian acacias. In the longer term, new encounter pests and pathogens will also threaten these trees in their native environments. [ABSTRACT FROM AUTHOR]

Abstract: Tabanid flies in Australia are potential vectors of the parasite Trypanosoma evansi which causes the animal disease surra. It is endemic to most of south-east Asia and could enter Australia, but evaluation of the potential impact of a surra incursion requires identification of the major hosts of Australian tabanids. This study investigated the natural pattern of feeding and host preference by tabanid flies of Townsville, north Queensland by identification of ingested blood in trap-caught tabanids using ELISA. The assays were developed for identification of horse, cow, macropod and pig blood meals. Macropods were the most frequent food source for each of six major tabanid species in the area. This did not vary with location for one species, Tabanus pallipennis, despite macropod densities being lower than other hosts such as cattle and horses in some locations. Feeding patterns on other hosts generally depended on availability and density of animals. All tabanid species fed on at least three of the host species tested and mixed meals were also commonly encountered, suggesting a level of opportunistic feeding in addition to a preference for macropods. Some of the blood meals detected were possibly from previous gonotrophic cycles. The results indicate that all tabanid species examined could potentially transmit surra and all the host types investigated could be affected, but macropods face the highest transmission risk. [ABSTRACT FROM AUTHOR]

The process of rapid range expansion (as seen in many invasive species, and in taxa responding to climate change) may substantially disrupt host-parasite dynamics. Parasites and pathogens can have strong regulatory effects on their host population and, in doing so, exert selection pressure on host life history. We construct a simple individual-based model of host-parasite dynamics during range expansion. This model shows that the parasites and pathogens of a range-expanding host are likely to be absent from the host's invasion front, because stochastic events (serial founder events) in low-density frontal populations result in local extinctions or transmission failure of the parasite/pathogen and, hence, a preponderance of uninfected hosts in the invasion vanguard. This pattern is true for both density-dependent and density-independent transmission rates, although it is exacerbated in the case of density-dependent transmission because, in this case, transmission rates also decline on the front. Data from field surveys on the prevalence of lungworms (Rhabdias pseudosphaerocephala) in invasive cane toads (Bufo marinus) support these predictions, in showing that toads in newly invaded areas of tropical Australia lack the parasite, which only arrives 1-3 years after the toads themselves. The resultant "honeymoon phase" immediately post-invasion, when individuals in the invasion-front population are virtually pathogen-free, may lead to altered host population dynamics on the invasion front, causing, for example, high densities in invasion-front populations, followed by a decline in numbers as parasites and pathogens arrive and begin to reduce host viability. The honeymoon phase may ultimately impact the evolution of life-history investment strategies in both host and parasite on the invasion vanguard, as hosts are released from immune challenges and parasites continuously expand into a favorable and unoccupied niche. [ABSTRACT FROM AUTHOR]

Abstract: Globally, cyanobacterial blooms are increasing along with observations of the controlling influence of viruses. Our aim here was to test whether viruses from an Australian freshwater lake could lyse the cyanobacterium Cylindrospermopsis raciborskii (Woloszynska) Seenaya and Subba Raju. C. raciborskii was selectively isolated from Lake Samsonvale southeast Queensland Australia using a Modified Jaworski Medium (without any form of inorganic nitrogen). Microscopy confirmed the resulting culture of a single cyanobacterial species. Natural viral-like particles (VLPs) were incubated with C. raciborskii cells, the host abundance decreased by 86% in 5 days, while the number of VLPs increased stepwise. As a cell lysed, the filaments of cells split into smaller, but viable, fragments. This process may help disperse the cyanobacterium in the wild. Hence the use of this virus to control blooms may inadvertently encourage the dispersal of toxic filamentous cyanobacteria. The cyanophage (virus infecting cyanobacteria) replication time was 21 h, with an average burst size of 64 viruses cell−1. Transmission Electron Microscopy showed this cyanophage for C. raciborskii, with its long, non-contractile tail and a capsid diameter of 70 nm, belongs to the Siphoviridae family of viruses. This cyanophage can affect the abundance and distribution of the cyanobacterium C. raciborskii in this Australian freshwater lake. [Copyright &y& Elsevier]

The article presents a study which investigates the gastrointestinal nematode fauna of Lissolepis coventryi and Lissolepis luctuosus in Australia using preserved museum lizards. A description of the three new found species is presented. It states that these semi-aquatic hosts originated from a cool and damp environment. Further, the similarities of the two species of Spincauda indicated their common ancestry. It also mentions that cestode Oochoristica vacuolata recovered from L. coventryi.

Alterations in transmission of vector-borne zoonoses are often linked to environmental change. However, ecological processes that determine variability in potential for transmission are generally not well understood. Ross River virus (RRV, Togoviridae: Alphavirus) is a mosquito-borne zoonosis in Australia with a significant human disease burden. The inland southwest (Wheatbelt) of Western Australia (WA) is substantially affected by an anthropogenic salinization of agricultural land (dryland salinity). Aedes camptorhynchusThomson (Diptera: Culicidae) is the dominant vector of RRV in southwest WA and is halophilic. As such, dryland salinity may influence potential for RRV transmission by influencing interactions between Ae. camptorhynchusand mammalian hosts. We surveyed areas of the Wheatbelt with varying salinity impacts and found Ae. camptorhynchuswas more abundant in saline areas, whereas sheep Ovis aries(Linnaeus 1758, Bovidae) declined with increasing salinity. We used a deterministic model to examine interactions between Ae. camptorhynchusand mammals, and we assessed potential for RRV transmission. We found variation in potential for RRV transmission was positively related to increasing salinity and abundance of Ae. camptorhynchusand negatively associated with increasing abundance of Macropus fuliginosus(Desmarest 1817, Macropodidae). Abundance of Ae. camptorhynchusdetermined more variation in potential for RRV transmission than other variables. Accordingly, dryland salinity increases the zoonotic potential for RRV transmission primarily by facilitating abundance of Ae. camptorhynchus. Human RRV notifications do not currently reflect the salinity-RRV transmission potential in the Wheatbelt but appear to be associated with RRV activity in the enzootic coastal zone. We speculate dryland salinity is a determinant of potential for RRV transmission but not activity. Dryland salinity is predicted to expand two- to four-fold by 2050. Preservation and restoration of freshwater ecosystems may ameliorate the potential for transmission of RRV and possibly incidence of human disease. [ABSTRACT FROM AUTHOR]

Multilocus sequence typing of 56 Salmonella enterica subsp. enterica strains isolated from Australian wildlife hosts was performed. The results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. Strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution. [ABSTRACT FROM AUTHOR]

Summary A total of 2489 wildlife hosts from Australia were sampled in order to determine the fraction of hosts that harboured Salmonella enterica as a dominant member of the host's enteric community. Hosts sampled included fish, frogs, reptiles, birds and mammals from the four main climatic regions of Australia: desert, grassland, temperate and tropical. Salmonella enterica was predominately isolated from reptiles, in particular, lizards. It was also isolated from mammals, though not from any fish, frog or bird host. Salmonella enterica was more likely to be isolated from lizards living in desert or grassland regions of Australia compared with lizards inhabiting tropical or temperate regions. The low prevalence of S. enterica isolated from wildlife hosts in Australia indicates that Australian wildlife are unlikely to play a large role in disseminating S. enterica to humans and livestock. [ABSTRACT FROM AUTHOR]