Alan Lymbery

Context
Obtaining a source of genetic data is a key constraint in population genomic research.

Aims
In this study, single-nucleotide polymorphisms (SNPs) were generated from oblong turtle (Chelodina oblonga) cadavers, to ascertain whether decomposed tissue could be used as a source of genetic data and to investigate genetic variation.

Methods
Tissue was opportunistically collected from 47 cadavers following a mass mortality event during April 2024 at Bibra Lake, Western Australia. Genotyping was performed using a Chelodina DArTseq platform, with a high-density assay of 2.5 million sequence reads.

Key results
Genetic diversity and inbreeding were investigated for 39 individual C. oblonga, using 8053 SNPs retained from data filtering. Observed and expected heterozygosities (HO = 0.26, HE = 0.31) for C. oblonga were relatively low compared with other freshwater turtle species within Australia. A high inbreeding coefficient (FIS = 0.17) was also detected, suggesting that inbreeding may threaten C. oblonga population viability at Bibra Lake.

Conclusions
This study highlights the utility of decomposed turtle cadavers as a viable source of DNA.

Implications
Management plans should implement strategies to improve gene flow between Bibra Lake and adjacent populations, such as establishing wildlife corridors to encourage migration between populations.

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.

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.

Alexandrium spp. blooms produce a range of toxins, including spirolides, goniodomins, and paralytic shellfish toxins (PSTs). Of these, PSTs are the most impactful due to their high affinity for voltage-gated sodium ion channels in nerve cell membranes. This interaction can cause neurological effects such as paralysis and, in severe cases, may lead to death. Given the implications of Alexandrium blooms on public health, all mitigation, prevention, and treatment strategies aim to reduce their socioeconomic impacts. However, monitoring harmful algal blooms remains difficult due to confounding influences such as pollution, climate change, and the inherent variability of environmental conditions. These factors can complicate early detection and management efforts, especially as the intensity and frequency of blooms continue to rise, further exacerbating their socioeconomic consequences. This review offers insights into several management approaches to prevent and control Alexandrium blooms, focusing on modified nano-clays as a promising emergency mitigation measure for low-density toxic algal blooms, especially in areas predominantly used for recreational fishing. However, it is recommended that treatment be coupled with monitoring to alleviate reliance on treatment alone.

Key Contribution
Prevention and control strategies for Alexandrium blooms should consider the specific use of the affected waterway, the carbon footprint associated with modified clay production, and the broader ecological and environmental impacts of clay application. These factors are essential when evaluating the overall efficiency and sustainability of clay-based treatment methods.

Alexandrium spp. blooms and paralytic shellfish poisoning pose serious economic threats to coastal communities and aquaculture. This study evaluated the removal efficiency of two Alexandrium minutum strains using natural kaolinite clay (KNAC) and kaolinite with polyaluminum chloride (KPAC) at three concentrations (0.1, 0.25, and 0.3 g L−1), two pH levels (7 and 8), and two cell densities (1.0 and 2.0 × 107 cells L−1) in seawater. PAC significantly enhanced removal, achieving up to 100% efficiency within two hours. Zeta potential analysis showed that PAC imparted positive surface charges to the clay, promoting electrostatic interactions with negatively charged algal cells and enhancing flocculation through Van der Waals attractions. In addition, the study conducted a cost estimate analysis and found that treating one hectare at 0.1 g L−1 would cost approximately USD 31.75. The low KPAC application rate also suggests minimal environmental impact on benthic habitats.

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% CI 125.4–229.7) mL/g dry tissue/hour in the laboratory and 210.9 (95% CI 171.6–250.2) mL/g dry tissue/hour in the field. Clearance rate increased with temperature, with maximum rates recorded at 25 ºC, and smaller mussels had higher mass-specific clearance rates. Clearance rate estimates aligned with rates in other hyriid mussels. Given its biofiltration capabilities, W. carteri may aid in maintaining water quality in intermittently flowing rivers of south-western Australia, where decreasing streamflow due to climate change is increasing the duration of drying in smaller, warmer and increasingly isolated refuge pools.

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.

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 ~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 Excel file provided here contains data used in a study of the repeatabilities and correlations among behavioural traits in western pygmy perch (Nannoperca vittata), a threatened freshwater fish species endemic to south-western Australia, and the guppy (Poecilia reticulata), a species frequently used in personality research.
Each fish (48 of each species) was measured four times for each of seven behavioural traits, which were 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) as measures of boldness; latency to approach to a novel object (LA) and time spent close to the object (TS) as measures of exploration; time spent close to a mirror (CV) as a measure of sociability; and number of attacks (AT) launched at the mirror as a measure of aggression.

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.