Conference Agenda

The genus Amblyomma is a monophyletic lineage of hard ticks, many species of which parasitize reptiles. The last taxonomic revision of the Amblyomma of Australia was by the great Bob Roberts of Brisbane in 1970. That revision relied solely on morphology. I will present the first molecular phylogenetic tree of the Amblyomma of Australia, with emphasis on the subgenus Cernyomma. My phylogenetic analyses revealed some cryptic species and new host-associations. Additionally, I will present a new diagnostic key of them.

Australia is home to a diverse array of invasive mammals, including pigs, deer, cats, foxes, and rabbits. Although these five species have been reported as hosts to protozoan parasites of the family Sarcocystidae in their native ranges, there has been little investigation into the parasite load of these invasive species in Australia. This study aims to fill in some of this gap by studying species from 3 genera within the Sarcocystidae in selected invasive mammalian hosts. Tissues were collected through opportunistic sampling of deceased invasive mammal species around south-eastern Australia and underwent molecular analysis through PCR and DNA sequencing. This has resulted in species from the genera Toxoplasma and Sarcocystis being identified in invasive mammals. From these identifications a better understanding of the indirect impact invasive animal hosts may be having on an environment through the transmission of parasites through ecosystems, can be drawn. This includes possible spillover into native wildlife hosts which may affect efforts for conservation and relocations. As well as this, spillover into domestic hosts, such as in farming, can affect yields, profits, and risk human health, or represent a risk to household pets.

The eastern paralysis tick, Ixodes holocyclus, causes potentially fatal toxin-mediated paralysis in susceptible domestic animals, livestock, and humans, often requiring urgent medical or veterinary intervention. Yet bandicoots are major natural hosts and appear comparatively tolerant of tick infestation. The mechanism underlying this host difference remains unresolved. This project investigates whether adaptive humoral immunity may contribute to bandicoot protection against the eastern paralysis tick. We are using a comparative omics approach to identify and annotate immunoglobulin-related sequences in Queensland bandicoots, focusing on Isoodon macrourus and Perameles nasuta, with Perameles gunnii included as a closely related reference species. Publicly available bandicoot expressed sequence tags, and the available P. nasuta transcriptome are being analyzed alongside collaborator-supplied P. gunnii genomic data and marsupial immunoglobulin datasets using homology-based annotation. Blood-derived samples from tick-infested I. macrourus and P. nasuta have also been submitted for whole-genome sequencing by Pacific Biosciences high-fidelity long-read sequencing and Hi-C scaffolding to improve recovery of immune loci, including antibody regions. Peripheral blood RNA sequencing will further support identification of expressed immunoglobulin transcripts. Annotated candidate sequences will guide degenerate primer design for future amplification of bandicoot antibody regions and test whether humoral immune responses contribute to natural tolerance of I. holocyclus.

Opportunistic sampling provides a valuable avenue for understanding the health and disease status of wildlife that are otherwise difficult to study. We report findings from a necropsy conducted on a road-killed Malleefowl (Leipoa ocellata) collected in the Fitz-Stirling region of Western Australia during a broader dietary ecology project. Although the original study did not target disease, the carcass presented a rare opportunity to conduct to investigate both ectoparasite and endoparasite communities in this cryptic and nationally vulnerable species. Few parasitological studies have been conducted on this vulnerable species and those that exist are dated. With increasing human encroachment into wildlife habitats and the spread of invasive species, understanding parasite loads and associated risks is becoming increasingly important. This is particularly relevant for Malleefowl, whose ground dwelling and mound building behaviours may increase exposure to soil dwelling parasites, and whose declining populations mean biological samples are rarely available. As many native species face pressure from habitat loss and fragmentation, climate change, and emerging diseases, integrating opportunistic necropsies into ecological and conservation programs can substantially enhance surveillance capacity. This case study underscores the importance of maximising information gained from unexpected wildlife encounters, including road‑kill specimens, to better inform management and conservation strategies.

Parasitism poses significant health challenges for the endangered Australian sea lion (Neophoca cinerea). Australian sea lion pups experience a high prevalence of the endemic hookworm (Uncinaria sanguinis) which is associated with reduced pup body condition and increased mortality. We examined faecal DNA from Australian sea lion pups (n = 63) to further explore host parasite interactions with an emphasis on apicomplexan parasitism. Screening of samples using an Apicomplexan genera PCR targeting the 18S rDNA gene resulted in 51 of the 63 DNA positive samples. DNA sequencing revealed a single parsasite sequence with high similarity between samples from Australian sea lion pups (99.9%) across 900 basepairs. A BlastN Seach identified the sequence from Australian sea lion pups to be 99.7% similar to Neopsora caninum. This first report of N. caninum in Australian sea lion pups demonstrates the environmental continuum that connects parasites associated with terrestrial animals to marine wildlife, and the significance of One Health for wild marine species. Understanding of the impact of N. caninum, and the significance of co-infection with hookworm, for pup health is important for Autstralian sea lion conservation and future management of this endangered marine mammal.

Nasal mites of the family Halarachnidae are common parasites of pinnipeds, although rarely reported in walruses. Two captive walruses at the Ocean Park Aquarium, Hong Kong, were found to be infected with nasal mites identified as Orthohalarachne attenuata (Banks, 1910). Long-term, low-dose ivermectin treatment for heartworm prevention (0.01 mg/kg) had no effect on parasite burden. In contrast, anti-parasitic doses of ivermectin (0.2mg/kg), administered repeatedly over a short-term period (4 doses, 2 weeks apart, followed by 3 doses administered monthly), appeared to successfully clear the parasitic infection, with no signs of re-infection observed for over 12 months post-treatment.