Ecological Risk Assessment for the State-wide Small Pelagic Scalefish Resource

In July 2021, the Department of Primary Industries and Regional Development convened an ecological risk assessment (ERA) of the fisheries that access the State-wide Small Pelagic Scalefish Resource. The ERA considered the potential ecological impacts of the West Coast Purse Seine Fishery, South Coast Purse Seine Fishery, Purse Seine Development Zones and the recreational fishers who catch small pelagic scalefish. The assessment evaluated the impact of each fishing sector/method on all relevant retained and bycatch species, endangered, threatened and protected species, habitats and the broader environment

Ecological Risk Assessment for the Temperate Demersal Elasmobranch Resource

In March 2021, the Department of Primary Industries and Regional Development (Department) convened an ecological risk assessment (ERA) of the fisheries that access the Temperate Demersal Elasmobranch Resource (Resource). ERAs are conducted by the Department as part of its Ecosystem Based Fisheries Management framework

Rates of population differentiation and speciation are decoupled in sea snakes

Comparative phylogeography can inform many macroevolutionary questions, such as whether species diversification is limited by rates of geographical population differentiation. We examined the link between population genetic structure and species diversification in the fully aquatic sea snakes (Hydrophiinae) by comparing mitochondrial phylogeography across northern Australia in 16 species from two closely related clades that show contrasting diversification dynamics. Contrary to expectations from theory and several empirical studies, our results show that, at the geographical scale studied here, rates of population differentiation and speciation are not positively linked in sea snakes. The eight species sampled from the rapidly speciating Hydrophis clade have weak population differentiation that lacks geographical structure. By contrast, all eight sampled Aipysurus-Emydocephalus species show clear geographical patterns and many deep intraspecific splits, but have threefold slower speciation rates. Alternative factors, such as ecological specialization, species duration and geographical range size, may underlie rapid speciation in sea snakes.Charlotte R. Nitschke, Mathew Hourston, Vinay Udyawer and Kate L. Sander

Combination of acellular dermal matrix with a de-epithelialised dermal flap during skin-reducing mastectomy and immediate breast reconstruction

INTRODUCTION: Patients with large ptotic breasts undergoing immediate implant-based reconstruction often require skin-reducing mastectomy to optimise the aesthetic outcome. However, healing complications, especially at the resulting inverted T-junction, leading to wound dehiscence, infection, skin necrosis, implant exposure and failed reconstruction have been widely reported. We present an innovative approach for immediate implant-based reconstruction combining porcine- or bovine-derived acellular dermal matrices with a de-epithelialised dermal sling to protect and support the implant, while improving clinical outcomes in this challenging group of patients. MATERIALS AND METHODS: Demographic, tumour and surgical data were reviewed for patients undergoing Wise pattern (T-scar) skin-reducing mastectomies with immediate implant-based reconstruction combining porcine- or bovine-derived acellular dermal matrices with a de-epithelialised dermal sling. RESULTS: This technique was successfully employed to reconstruct five large pendulous breasts in four breast cancer patients with a median age of 50.5 years (range 34–61 years) who were not suitable for, or had declined, flap-based reconstruction. The acellular dermal matrices used were SurgiMend®, StratticeTM and Braxon® and the expandable implants were placed in the sub-pectoral (n = 3) and pre-pectoral (n = 1) planes. The technical steps and clinical outcomes are presented. One patient experienced T-junction breakdown overlying the de-epithelialised dermis without implant loss. CONCLUSION: The combination of an acellular dermal matrix and a dermal sling provides a double-layer ‘water-proofing’ and support for the implants inferiorly, avoiding T-junction breakdown complications, since any dehiscence is on to well-vascularised dermis. Furthermore, the acellular dermal matrix stabilises the implant in the large mastectomy cavity (pocket control). This approach provides a viable option which facilitates mastectomy and immediate implant reconstruction in large-breasted patients

Fruit fracture biomechanics and the release of Lepidium didymum pericarp-imposed mechanical dormancy by fungi

Mechanical dormancy imposed by a hard fruit pericarp prevents premature seed germination. Here, the authors show that the pericarp of Lepidium didymum prevents germination by limiting water uptake and that dormancy can be released by fungal activity that weakens predetermined breaking zones in the fruit coat

Lateral Transfer of a Lectin-Like Antifreeze Protein Gene in Fishes

Fishes living in icy seawater are usually protected from freezing by endogenous antifreeze proteins (AFPs) that bind to ice crystals and stop them from growing. The scattered distribution of five highly diverse AFP types across phylogenetically disparate fish species is puzzling. The appearance of radically different AFPs in closely related species has been attributed to the rapid, independent evolution of these proteins in response to natural selection caused by sea level glaciations within the last 20 million years. In at least one instance the same type of simple repetitive AFP has independently originated in two distant species by convergent evolution. But, the isolated occurrence of three very similar type II AFPs in three distantly related species (herring, smelt and sea raven) cannot be explained by this mechanism. These globular, lectin-like AFPs have a unique disulfide-bonding pattern, and share up to 85% identity in their amino acid sequences, with regions of even higher identity in their genes. A thorough search of current databases failed to find a homolog in any other species with greater than 40% amino acid sequence identity. Consistent with this result, genomic Southern blots showed the lectin-like AFP gene was absent from all other fish species tested. The remarkable conservation of both intron and exon sequences, the lack of correlation between evolutionary distance and mutation rate, and the pattern of silent vs non-silent codon changes make it unlikely that the gene for this AFP pre-existed but was lost from most branches of the teleost radiation. We propose instead that lateral gene transfer has resulted in the occurrence of the type II AFPs in herring, smelt and sea raven and allowed these species to survive in an otherwise lethal niche