Justin M. McNab

Aega serricauda sp. nov., from southeastern Australian waters, belongs to a group of species within Aega that is characterised by a strongly flattened antennula peduncle, a prominent seta opposing the dactylus on pereopods 2 or 2 and 3, and moderately to strongly serrate margins to the pleotelson and uropods. In addition, species in this group have elongate bodies with subparallel margins. Aega serricauda is characterized by the pleotelson being nearly as long (0.97 ratio) as wide, a clearly angled posterior margin (that part that is serrated, with slender and robust setae) that forms an angle of 95° at the apex, lateral margins (the lateral part free of setae) comprising 40% or pleotelson length, and uropodal rami extending to or slightly beyond the pleotelson posterior margin. A. serricauda sp. nov. has been recorded in waters off eastern Tasmania and was collected from the surface of three species of elasmobranch: Galeorhinus galeus (school shark), Squalus acanthias (spiny dogfish) and Dipterus cerva (white spotted skate).

Background: The black soldier fly (BSF), Hermetia illucens is a widely used, and mass-produced insect that fulfils an important role in both the management of organic waste and as a component of animal feed formulations. They also have significant potential as a platform for converting organic waste into high-value proteins, and lipids for the production of biofuels. Applying synthetic biology to BSF provides even more potential for improvement through the generation of transgenic BSF to enhance animal feed, produce and fine tune high-value industrial biomolecules, and to expand their waste conversion capabilities. Results: To enable the rapid generation and screening of transgenic BSF, we utilised microinjections of piggyBac mRNA with donor plasmids. We have found preliminary screening of G0 BSF to identify mosaics for outcrossing can be completed less than 2 weeks after microinjection. Stable transgenic lines were reliably generated with effective transformation rates of 30-33%, and transmission of the transgene could be confirmed 3 days after outcrossing the G0 adults. We also present a protocol for identifying the location of integrated transgenes. Conclusions: The methods presented here expedite the screening process for BSF transgenesis and further expand the toolkit for BSF synthetic biology.

Animals are often faced with time-critical decisions without prior information about their actions’ outcomes. In such scenarios, individuals budget their investment into the task to cut their losses in case of an adverse outcome. In animal groups, this may be challenging because group members can only access local information, and consensus can only be achieved through distributed interactions among individuals. Here, we combined experimental analyses with theoretical modeling to investigate how groups modulate their investment into tasks in uncertain conditions. Workers of the arboreal weaver antOecophylla smaragdinaform three-dimensional chains using their own bodies to bridge vertical gaps between existing trails and new areas to explore. The cost of a chain increases with its length because ants participating in the structure are prevented from performing other tasks. The payoffs of chain formation, however, remain unknown to the ants until the chain is complete and they can explore the new area. We demonstrate that weaver ants cap their investment into chains, and do not form complete chains when the gap is taller than 90 mm. We show that individual ants budget the time they spend in chains depending on their distance to the ground, and propose a distance-based model of chain formation that explains the emergence of this tradeoff without the need to invoke complex cognition. Our study provides insights into the proximate mechanisms that lead individuals to engage (or not) in collective actions and furthers our knowledge of how decentralized groups make adaptive decisions in uncertain conditions.

There is a rapid and extensive decline of our marine biodiversity due to human impacts. However, our ability to understand the extent of these effects is hindered by our lack of knowledge of the occurrence and ecology of some species groups. One such group of understudied organisms are marine flatworms of the order Polycladida, a conspicuous component of southeastern Australia’s marine ecosystems that has received little attention over the years. Intertidal boulder beaches support a diverse range of polyclad flatworms in other countries, but the role of these environments in maintaining biodiversity is not well understood. In this study, we identified hotspots of flatworm occurrence by assessing the diversity and overall abundance of flatworms at boulder beaches along the southeast Australian coast. Bottle and Glass, Sydney Harbour, was found to be the most diverse site for flatworms. We also identified a higher occurrence of flatworms under large boulders and less exposed beaches and noted an increased presence of flatworms at higher latitudes. Probable influences on these patterns such as the requirement for shelter and protection are discussed. This study contributes to our knowledge of Australia’s coastal biodiversity and can be used to assist in the management and conservation of our marine environments.

Tetrodotoxin (TTX) is a potent marine neurotoxin that occurs in several Australian phyla, including pufferfish, toadfish, gobies, and the blue-ringed octopus. These animals are partially immune, and TTX is known to bioaccumulate and subject to trophic transfer. As such, it could be more ubiquitously distributed in animals than is currently known. Flatworms of the order Polycladida are commonly occurring invertebrates in intertidal ecosystems and are especially diverse in Australian waters. While TTX has been identified in polyclads from Japan and New Zealand, Australian species have yet to be tested. In this study, several eastern Australian polyclad flatworm species from the suborders Cotylea and Acotylea were tested for TTX and analogs by HILIC-HRMS to understand the distribution of this toxin within these suborders. Herein, we report the detection of TTX and some known analogs in polyclad species, one of which is a pest to shellfish aquaculture. We also report, for the first time, the application of MALDI mass spectrometry imaging utilized to map TTX spatially within the intestinal system of polyclads. The identification of TTX and its analogs in Australian flatworms illustrates a broader range of toxic flatworms and highlights that analogs are important to consider when studying the distributions of toxins in animals.

Marine invertebrates are promising sources of novel bioactive secondary metabolites, and organisms like sponges, ascidians and nudibranchs are characterised by possessing potent defensive chemicals. Animals that possess chemical defences often advertise this fact with aposematic colouration that potential predators learn to avoid. One seemingly defenceless group that can present bright colouration patterns are flatworms of the order Polycladida. Although members of this group have typically been overlooked due to their solitary and benthic nature, recent studies have isolated the neurotoxin tetrodotoxin from these mesopredators. This review considers the potential of polyclads as potential sources of natural products and reviews what is known of the activity of the molecules found in these animals. Considering the ecology and diversity of polyclads, only a small number of species from both suborders of Polycladida, Acotylea and Cotylea have been investigated for natural products. As such, confirming assumptions as to which species are in any sense toxic or if the compounds they use are biosynthesised, accumulated from food or the product of symbiotic bacteria is difficult. However, further research into the group is suggested as these animals often display aposematic colouration and are known to prey on invertebrates rich in bioactive secondary metabolites.