This study evaluated the effects of replacing fishmeal with microbial single-cell proteins (SCPs) in diets for juvenile yellowtail kingfish (YTK, Seriola lalandi), assessing growth, feed efficiency, nutrient digestibility, gut histology and microbiome, blood biochemistry and gene expression. Eight experimental diets were formulated, using methanotrophic (SB) and hydrogenotrophic (LT) SCPs at inclusion levels of 4 %, 8 %, and 16 %, alongside a control diet (42.2 % fish meal) and a combination diet (4 % SB + 4 % LT). Fish were reared in 500 L tanks for 12 weeks, after which growth performance, feed intake, feed conversion ratio (FCR) and health indices were measured. Significant improvements in FCR were observed in the 8 % SB and 16 % SB groups (0.99 and 0.98, respectively), compared to the control diet (1.06). Protein and energy retention were also highest in the 8 % SB and 16 % SB diets, with respective retention efficiencies of 39.0 % and 37.8 %. Apparent digestibility was comparable across diets, with protein digestibility peaking at 87.9 % in the 4 % SB + 4 % LT diet. Histological analysis revealed no significant changes in intestinal or skin integrity. Blood biochemistry, hematology, gene expression profiles and microbiome were unaffected by SCP inclusion, except for a notable decrease in gut bacterial diversity in fish fed the 4 % SB + 4 % LT diet. Overall, these results demonstrate that SCPs, particularly SB at 8 % and 16 % inclusion levels, can effectively replace fishmeal in YTK diets without compromising health or growth, while enhancing feed efficiency and nutrient retention.

Freshwater mussels are keystone species in freshwater streams, providing important ecosystem services, including biofiltration. While most research has focussed on Unionidae mussels in northern hemisphere perennial rivers, far less is known about the biofiltration capacities of Hyriidae mussels, which are prevalent in intermittent rivers in arid and semi-arid regions of the southern hemisphere. This study examined biofiltration of the imperilled Australian hyriid, Westralunio carteri. We estimated biofiltration capacity by measuring reduction in algal concentration across three temperatures (15, 20 and 25 ºC) under laboratory conditions. We then validated these laboratory results with field experiments using natural seston. Westralunio carteri exhibited a mean clearance rate of 177.5 (95

Mosquitoes (Culicidae) are the most important vectors of human and animal diseases globally, making them valuable tools for the molecular surveillance of blood-borne pathogens. By screening mosquito populations, we can evaluate local disease prevalence and ascertain which vector species are involved in local transmission cycles. This study presents the first targeted mosquito-based surveillance of blood parasites in Western Australia. Over a 2-year surveillance program in Perth, Western Australia, 3,288 mosquitoes from 12 species across 5 genera were collected and screened in 461 pools. Parasite prevalence and diversity were evaluated using polymerase chain reaction screening of the Haemosporida cytochrome b gene region, and the Dirofilaria 12S rDNA gene region. Haemosporida were detected in 3.9% of mosquito pools, with 72.2% of positives found in Culex species pools. Avian Haemosporida comprised 83.3% of the total detections. Known avian Haemosporida lineages detected included 1 Haemoproteus (H. zosteropis) and 2 Plasmodium (BELL01 and MYNA02). Three novel lineages, Plasmodium CULPER01-03, were identified. Plasmodium falciparum was identified in 2 pools, and no Dirofilaria were detected. These findings indicate that Perth harbors a diverse range of avian Haemosporida, which may be regionally specific, as all lineages detected have only been identified in the Oceania region. The predominance of positive detections in the Culex pipiens species complex supports their role as the primary vectors of avian Plasmodium. This study highlights the utility of mosquito surveillance for monitoring blood-borne parasites and contributes new insight into parasite diversity and vector associations in Australia.

BACKGROUND:With the global expansion of aquaculture and the increasing demand for fish meal, identifying appropriate and sustainable alternative protein sources for aquafeeds has become essential. Single-cell protein (SCP), derived from methanotrophic bacteria, presents a promising alternative by converting methane into protein, potentially addressing both the need for alternative protein sources and reducing industrial greenhouse gas emissions. This study aimed to evaluate the effects of different levels of SCP inclusion (0%, 25%, 50%, and 75% fish meal replacement) on the health, gene expression, and gut microbiome of yellowtail kingfish (YTK, Seriola lalandi) following a 35-day growth trial. RESULTS:The study found that SCP inclusion at the highest level of fishmeal replacement (75%) induced a mild inflammatory response in the hindgut of the fish. However, micromorphological assessments of the hindgut, serum biochemistry, and gene expression analyses revealed no significant detrimental effects from SCP replacement. Notably, there were indications of improved lipid digestibility with SCP. Furthermore, SCP inclusion significantly enhanced microbial richness and altered the composition of the gut microbiome, introducing beneficial bacterial taxa that may contribute to improved gut health and resilience. CONCLUSIONS:This study highlights SCP as a viable and sustainable alternative to fish meal in YTK diets. The findings suggest that SCP can be included in YTK diets without adverse health effects at moderate levels and may even offer benefits in terms of lipid digestibility and gut microbiome diversity. These results contribute to the advancement of more sustainable aquaculture practices.

Reducing fishmeal (FM) in aquaculture diets is essential for improving sustainability and reducing reliance on marine resources. Black soldier fly (BSF; Hermetia illucens) larvae meal is a promising alternative protein source. This study evaluated the effects of replacing FM with BSF meal on the growth and health of juvenile yellowtail kingfish (YTK) (Seriola lalandi, initial weight ~22 g). Fish were reared in 24 tanks (three replicates per treatment) and fed for 33 days under controlled conditions. Eight diets were tested: a control (40% FM) and seven diets with BSF meal replacing FM at 25%, 50%, or 75%, with or without garlic and tuna hydrolysate additives. Fish fed 25% and 50% BSF diets showed growth and feed conversion comparable to the control, while 75% BSF significantly reduced growth due to decreased feed intake. Additives did not improve feed intake. Histological analysis indicated good gut health and nutrient absorption. Serum cholesterol decreased with BSF inclusion, and urea levels varied. No significant changes in gene expression were observed in the gut, liver, or brain. Microbiome analysis showed increased diversity and compositional shifts at higher BSF levels. These results support the use of BSF meal as a sustainable FM replacement at moderate inclusion levels, with further research needed to address palatability at higher levels.

This study reports the metazoan ectoparasite fauna of juvenile Critically Endangered green sawfish, Pristis zijsron, and sympatric elasmobranchs in Western Australia. Five parasite taxa were found on 76 screened P. zijsron: Caligus furcisetifer (Copepoda: Caligidae), Dermopristis pterophila (Monogenea: Microbothriidae), Branchellion plicobranchus and Stibarobdella macrothela (Hirudinea: Piscicolidae), and praniza larvae of an unidentified gnathiid isopod. Only C. furcisetifer and D. pterophila were common, exhibiting discrepant site-specificity, with C. furcisetifer occurring mostly on the head and rostrum, and D. pterophila around the pectoral and pelvic fins. Intensity of infection for C. furcisetifer and D. pterophila increased with host total length and was influenced by host sex, but in opposite directions; intensity of C. furcisetifer was greater on female P. zijsron, whereas intensity of D. pterophila was greater on males. In the Ashburton River, likelihood of infection for C. furcisetifer and D. pterophila on P. zijsron increased with time since substantial freshwater discharge events, suggesting decreased salinity impacts both taxa. In addition to P. zijsron, five other sympatric elasmobranch species were opportunistically screened for ectoparasites in the study area: the giant shovelnose ray, Glaucostegus typus, the eyebrow wedgefish, Rhynchobatus palpebratus, the nervous shark, Carcharhinus cautus, the lemon shark, Negaprion acutidens, and the graceful shark, Carcharhinus amblyrhynchoides. Caligus furcisetifer was found on R. palpebratus; no other parasites of P. zijsron were found on other sympatric elasmobranch species. Conversely, Perissopus dentatus (Copepoda: Pandaridae) was found on all three carcharhinids but not on batoid rays (P. zijsron, G. typus or R. palpebratus).

Estuaries that become closed from the ocean through the formation of a sand bar are particularly susceptible to degradation and often experience poor water quality and fish kills. Sampling was conducted seasonally for two years in the deeper waters of the Vasse–Wonnerup (southwestern Australia) after a large fish mortality event to identify the fish species present and determine if richness, abundance, diversity and faunal composition differed among regions and over time. Species richness, abundance and diversity were far greater in the downstream regions than in the upstream regions, reflecting patterns in salinity. Catch rates of two marine estuarine-opportunist mugilids (Mugil cephalus and Aldrichetta forsteri) and an estuarine-resident sparid (Acanthopagrus butcheri), which were the species most affected by the mortality event, were relatively stable. It is suggested that before sampling commenced, mugilids had entered the estuary following an artificial sand bar breach, while the loss of 0+ (new recruits) A. butcheri in the mortality event and subsequent recruitment failure prevented stocks from increasing. Temporal shifts in fish composition were driven by less abundant species, which utilized the estuary more opportunistically. Increases in the occurrences and abundances of these species coincided with an open bar and salinities close to those of seawater. The data also show how the estuary responds to differing hydrodynamic phases and artificial breaches.

Animal personalities are differences in behaviour among individuals of the same species that are consistent over time and contexts. The integration of animal personality into conservation actions is hampered by limited understanding of personality traits in non-model organisms. We estimated repeatabilities and correlations between behaviours in Nannoperca vittata (western pygmy perch), a threatened freshwater fish species endemic to south-western Australia, and, for comparative purposes, in Poecilia reticulata (guppy), a species frequently used in personality research. Each fish was measured four times for each of seven behavioural variables, presumed to reflect five underlying personality traits. Track length (TL) was used as a measure of activity; time spent in a risky zone (RZ) and time to emergence (ET) for boldness; latency to approach a novel object (LA) and time spent close to the object (TS) for exploration; time spent close to a mirror (CV) for sociability and number of attacks at the mirror (AT) for aggression. Four behavioural variables (TL, RZ, ET and CV) were significantly repeatable in N. vittata and also in P. reticulata. There was a lack of concordance in phenotypic and among-individual correlations between variables in both species, emphasising the importance of partitioning trait covariances to infer behavioural syndromes. Significant among-individual correlations were found between activity, boldness and sociability variables in N. vittata , consistent with a proactive-reactive personality axis, but not in P. reticulata . Personality variation should be considered in conservation actions for N. vittata , particularly with respect to unintended consequences of domestication selection in captive breeding and release.

This study examined the metazoan ectoparasites of the Critically Endangered giant shovelnose ray, Glaucostegus typus, in the eastern Indian Ocean. We screened 186 G. typus for ectoparasites in four coastal regions of Western Australia between 2020 and 2022: the Pilbara Region, Exmouth Gulf, Ningaloo Coast and Shark Bay. Five parasite taxa were encountered on 186 G. typus: Caligus furcisetifer (Copepoda: Caligidae), Dermopristis cairae (Monopisthocotyla: Microbothriidae), Branchellion plicobranchus and Stibarobdella macrothela (Hirudinida: Piscicolidae), and praniza larvae of unidentified gnathiid isopod/s (Isopoda: Gnathiidae). Two of these species, B. plicobranchus and S. macrothela, are reported for the first time on G. typus. Only C. furcisetifer and S. macrothela were relatively common, encountered on 31

Mass die-offs, reduced species richness and local extinctions of freshwater mussels have resulted from river drying events, which often co-occur with high ambient temperatures. These events are predicted to increase in frequency and severity under the influence of climate change. We aimed to identify the desiccation tolerance of two freshwater mussel species (the river mussel Alathyria jacksoni and the floodplain mussel Velesunio ambiguus) across a range of temperatures by simulating river drying events in laboratory conditions. Freshwater mussels were buried in sediment heated to 29, 32, 35, 38 and 41°C. Lethal times and lethal temperatures at which 50

In this study, single nucleotide polymorphisms were used to investigate kinship and philopatry for the Critically Endangered green sawfish, Pristis zijsron, in Western Australia. Sampling was conducted in an important nursery area: the Ashburton River estuary and adjacent tidal creeks. Kinship was inferred from the genotypes of 104 sawfish sampled between 2011 and 2014 (n = 31), and 2020 and 2022 (n = 73). The total number of dams contributing across all sites and time periods was estimated to be between 50 and 56. Fifty-two full sibling dyads, 90 half sibling dyads and 72 third-degree dyads were detected, involving 58, 67, and 46 P. zijsron, respectively. Of these, 34 half sibling dyads were related maternally and 56 related paternally, including multiple maternal and paternal half siblings pupped in different years, suggesting both female and male philopatry. Catch data indicated that two groups of maternal half siblings were littermates, demonstrating multiple paternity. A high degree of relatedness was found across the study area, with 88% of P. zijsron related to at least one other individual up to the third-degree. Evidence for female philopatry in P. zijsron highlights the importance of protecting nursery areas for this species. The occurrence of philopatric behaviour in male and female P. zijsron suggests that dispersal might be limited in both sexes of this species, highlighting the need to investigate the amount of genetic diversity and incidence of inbreeding within remaining populations.

In this study, single nucleotide polymorphisms (SNPs) were used to investigate kinship, genetic diversity and inbreeding within a globally significant area for the Critically Endangered giant shovelnose ray, Glaucostegus typus (Anonymous [Bennett] 1830). Sampling for G. typus was conducted in the eastern Indian Ocean, along an expansive ( 1000 km) stretch of the Western Australian coastline. Single-read sequencing was performed using a Glaucostegus DArTseq™ platform, with a high-density assay of 2.5 million sequence reads. Kinship, genetic diversity and inbreeding were investigated for G. typus using between 564 and 4126 SNPs. Four full and four half sibling dyads were detected amongst 90 genotyped G. typus, including one pair of half siblings separated by > 600 km of coastline, providing evidence of long-distance, likely parental, movement. Observed heterozygosity (HO = 0.29–0.30) and gene diversity (HS = 0.32–0.33) were relatively low compared to other rays, although a lack of previous studies using SNP data may reduce the effectiveness of comparisons. Moderate levels of inbreeding were detected at each site (FIS = 0.07–0.13) and across all sites, combined (FIS = 0.09). Long-distance movement of G. typus between sampled assemblages reduces the risk of localised extinctions across the study area; additional work is required to determine whether the sampled assemblages are genetically distinct from one another, as well as other G. typus populations throughout its Indo-West Pacific range.

Context In this study, single-nucleotide polymorphisms (SNPs) were used to investigate kinship for the green sawfish (Pristis zijsron). Aims To examine the relatedness of P. zijsron across an expansive coastline in Western Australia. Methods Sampling was conducted between the Fitzroy River estuary and Bay of Rest in the eastern Indian Ocean (north-western Australia) between 2003 and 2022. SNPs were generated from tissues collected from 137 live and 1 recently deceased P. zijsron. Key results Overall, 62 individual P. zijsron were assigned to 25 litters of full siblings, with litter sizes ranging from 2 to 5 pups, and 76 P. zijsron individuals were assigned to 96 half sibling pairwise relationships. Four pairs of half siblings were captured more than 500 km and born at least 6 years apart, including one pair of neonates captured similar to 870 km and 8 years apart, in the Ashburton River estuary (Pilbara) and Cable Beach (Broome). Furthermore, a pair of full-sibling pups (i.e. young of the year) caught at Cape Keraudren (Pilbara) in 2008 were half siblings of a pup caught in the Ashburton River in 2014. Conclusions This study provides evidence of long-distance, likely parental, movement of P. zijsron. Implications Dispersal of P. zijsron over large spatial scales indicates that populations could be replenished from elsewhere should they experience a decline, thereby reducing the risk of localised extinction for this species.

The conservation management of threatened wildlife increasingly relies upon translocations to augment populations. Translocations, however, pose various risks: from the host perspective these include the spread of parasitic disease, whereas from a broader biodiversity perspective translocation may lead to the loss of rare parasites and other dependent fauna. Although Disease Risk Analyses are recommended during translocation planning, knowledge regarding the parasites infecting threatened species or their pathogenicity is often lacking. Between March 2014 and June 2016, woylies (Bettongia penicillata) and sympatric marsupials were screened for the presence of endo- and ectoparasites, during two fauna translocations in south-western Australia. Here, we summarise the parasite taxa identified from B. penicillata, brush-tailed possums (Trichosurus vulpecula hypoleucus) and chuditch (Dasyurus geoffroii), including prevalence data for host, parasite taxon and site. Results from the opportunistic sampling of other species (Isoodon fusciventer, Phascogale tapoatafa wambenger, Tiliqua rugosa and Felis catus) are also presented. New host–parasite records including Hepatozoon spp. from T. v. hypoleucus, Trypanosoma noyesi from T. rugosa, Ixodes australiensis and Ixodes tasmani from D. geoffroii, and I. australiensis and Amblyomma sp. from a P. t. wambenger were identified. This study highlights the importance of monitoring sympatric species, particularly when compiling baseline data of parasite fauna present within translocation sites and enhances our knowledge of parasites infecting terrestrial wildlife within Australia’s south-west, a Global Biodiversity Hotspot.

Recently, Vibrio anguillarum, a Gram-negative pathogenic bacterium, has been becoming a major constraint on the development of the turbot aquaculture industry because of its characteristics of worldwide distribution, broad host range and potentially devastating impacts. Although the functions of protein-coding mRNAs in the immune response against bacterial infection have been reported, as well as several non-coding RNAs (ncRNAs), such as circular RNAs (circRNAs) and microRNAs (miRNAs), the relationships between mRNAs and ncRNAs in the immune system of turbot liver are still limited during bacterial infection. In present study, the comprehensive analyses of whole-transcriptome sequencing were conducted in turbot liver infected by V. anguillarum. The differential expression was analyzed in the data of circRNAs, miRNAs, and mRNAs. The interactions of miRNA-circRNA pairs and miRNA-mRNA pairs were predicted basing on the negative regulatory relationships between miRNAs and their target circRNAs\mRNAs. The circRNA-related ceRNA regulatory networks were constructed for the analyses of regulated mechanism in turbot immune system. Subsequently, the RT-qPCR was carried out to verify the results of sequencing. Finally, we identified 31 circRNAs, 53 miRNAs and 948 mRNAs with differential expression. Gene set enrichment analyses using Gene ontology (GO) and Kyoto Encyclopedia of Genes and Ge-nomes (KEGG) pathways showed that innate immunity was principally activated at the early stages of infection, while adaptive immunity was activated after 24 h. Finally, 65 circRNA-miRNA-mRNA pathways were con-structed, based on the hypothesis of ceRNA regulatory networks. In conclusion, our findings provide new insights on the underlying immune response to bacterial infection and identify novel target genes for the prevention and control of disease in turbot.

Gastrointestinal (GI) parasites cause significant morbidity and mortality worldwide. The use of conventional antiparasitic drugs is often inhibited due to limited availability, side effects or parasite resistance. Medicinal plants can be used as alternatives or adjuncts to current antiparasitic therapies. This systematic review and meta-analysis aimed to critically synthesise the literature on the efficacy of different plants and plant compounds against common human GI parasites and their toxicity profiles. Searches were conducted from inception to September 2021. Of 5393 screened articles, 162 were included in the qualitative synthesis (159 experimental studies and three randomised control trials [RCTs]), and three articles were included in meta-analyses. A total of 507 plant species belonging to 126 families were tested against different parasites, and most of these (78.4%) evaluated antiparasitic efficacy in vitro. A total of 91 plant species and 34 compounds were reported as having significant in vitro efficacy against parasites. Only a few plants (n = 57) were evaluated for their toxicity before testing their antiparasitic effects. The meta-analyses revealed strong evidence of the effectiveness of Lepidium virginicum L. against Entamoeba histolytica with a pooled mean IC50 of 198.63 mu g/mL (95% CI 155.54-241.72). We present summary tables and various recommendations to direct future research.

Despite advances in modern human and veterinary medicine, gastrointestinal (GI) parasitic infections remain a significant health issue worldwide, mainly in developing countries. Increasing evidence of the multi-drug resistance of these parasites and the side effects of currently available synthetic drugs have led to increased research on alternative medicines to treat parasitic infections. The exploration of potential botanical antiparasitics, which are inexpensive and abundant, may be a promising alternative in this context. This study summarizes the in vitro/in vivo antiparasitic efficacy of different medicinal plants and their components against GI parasites. Published literature from 1990-2020 was retrieved from Google Scholar, Web of Science, PubMed and Scopus. A total of 68 plant species belonging to 32 families have been evaluated as antiparasitic agents against GI parasites worldwide. The majority of studies (70%) were conducted in vitro. Most plants were from the Fabaceae family (53%, n = 18). Methanol (37%, n = 35) was the most used solvent. Leaf (22%, n = 16) was the most used plant part, followed by seed and rhizome (each 12%, n = 9). These studies suggest that herbal medicines hold a great scope for new drug discoveries against parasitic diseases and that the derivatives of these plants are useful structures for drug synthesis and bioactivity optimization.

BACKGROUND:With more than 36,000 valid fish species, teleost fishes constitute the most species-rich vertebrate clade and exhibit extensive genetic and phenotypic variation, including diverse immune defense strategies. NLRC3 subfamily genes, which are specific to fishes, play vital roles in the immune system of teleosts. The evolution of teleosts has been impacted by several whole-genome duplication (WGD) events, which might be a key reason for the expansions of the NLRC3 subfamily, but detailed knowledge of NLRC3 subfamily evolution in the family Sebastidae is still limited. RESULTS:Phylogenetic inference of NLRC3 subfamily protein sequences were conducted to evaluate the orthology of NLRC3 subfamily genes in black rockfish (Sebastes schlegilii), 13 other fish species from the families Sebastidae, Serranidae, Gasterosteidae and Cyclopteridae, and three species of high vertebrates (bird, reptile and amphibian). WGD analyses were used to estimate expansions and contractions of the NLRC3 subfamily, and patterns of expression of NLRC3 subfamily genes in black rockfish following bacterial infections were used to investigate the functional roles of these genes in the traditional and mucosal immune system of the Sebastidae. Different patterns of gene expansions and contractions were observed in 17 fish and other species examined, and one and two whole-genome duplication events were observed in two members of family Sebastidae (black rockfish and honeycomb rockfish, Sebastes umbrosus), respectively. Subsequently, 179 copy numbers of NLRC3 genes were found in black rockfish and 166 in honeycomb rockfish. Phylogenetic analyses corroborated the conservation and evolution of NLRC3 orthologues between Sebastidae and other fish species. Finally, differential expression analyses provided evidence of the immune roles of NLRC3 genes in black rockfish during bacterial infections and gene ontology analysis also indicated other functional roles. CONCLUSIONS:We hypothesize that NLRC3 genes have evolved a variety of different functions, in addition to their role in the immune response, as a result of whole genome duplication events during teleost diversification. Importantly, this study had underscored the importance of sampling across taxonomic groups, to better understand the evolutionary patterns of the innate immunity system on which complex immunological novelties arose. Moreover, the results in this study could extend current knowledge of the plasticity of the immune system.

Cryptosporidium parvum is a significant cause of watery diarrhoea in humans and other animals worldwide. Although hundreds of novel drugs have been evaluated, no effective specific chemotherapeutic intervention for C. parvum has been reported. There has been much recent interest in evaluating plant-derived products in the fight against gastrointestinal parasites, including C. parvum. This study aimed to identify extracts from 13 different plant species that provide evidence for inhibiting the growth of C. parvum in vitro. Efficacy against C. parvum was detected and quantified using quantitative PCR and immunofluorescence assays. All plant extracts tested against C. parvum showed varying inhibition activities in vitro, and none of them produced a cytotoxic effect on HCT-8 cells at concentrations up to 500 µg/mL. Four plant species with the strongest evidence of activity against C. parvum were Curcuma longa, Piper nigrum, Embelia ribes, and Nigella sativa, all with dose-dependent efficacy. To the authors' knowledge, this is the first time that these plant extracts have proven to be experimentally efficacious against C. parvum. These results support further exploration of these plants and their compounds as possible treatments for Cryptosporidium infections.