Environmental conditions experienced during the larval dispersal of marine organisms can determine the size-at-settlement of recruits. It is, therefore, not uncommon that larvae undergoing different dispersal histories would exhibit phenotypic variability at recruitment. Here, we investigated morphological differences in recently settled southern rock lobster () recruits, known as pueruli, along a latitudinal and temporal gradient on the east coast of Tasmania, Australia.
View Article and Find Full Text PDFWhile there is now strong evidence that many factors can shape dispersal, the mechanisms influencing connectivity patterns are species-specific and remain largely unknown for many species with a high dispersal potential. The rock lobsters and have a long pelagic larval duration (up to 20 months) and inhabit seamounts and islands in the southern Atlantic and Indian Oceans, respectively. We used a multidisciplinary approach to assess the genetic relationships between and , investigate historic and contemporary gene flow, and inform fisheries management.
View Article and Find Full Text PDFInvestigating historical gene flow in species complexes can indicate how environmental and reproductive barriers shape genome divergence during speciation. The processes influencing species diversification under environmental change remain one of the central focal points of evolutionary biology, particularly for marine organisms with high dispersal potential. We investigated genome-wide divergence, introgression patterns and inferred demographic history between species pairs of all six extant rock lobster species (Jasus spp.
View Article and Find Full Text PDFNational dietary guidelines (DGs) consistently recommend consuming seafood for health benefits, however, the sustainability of increasing seafood consumption is often challenged. Seafood products vary in environmental performance as well as health benefits, yet there is no information integrating the health and ecological impacts of different seafood choices. The first step in optimising improved health and environmental outcomes is to examine more closely the types of seafood being consumed at population and individual levels, to develop the means to increase the intake of seafood that is optimal for human health and the environment.
View Article and Find Full Text PDFObjective: Encouraging people to eat more seafood can offer a direct, cost-effective way of improving overall health outcomes. However, dietary recommendations to increase seafood consumption have been criticised following concern over the capacity of the seafood industry to meet increased demand, while maintaining sustainable fish stocks. The current research sought to investigate Australian accredited practising dietitians' (APD) and public health nutritionists' (PHN) views on seafood sustainability and their dietary recommendations, to identify ways to better align nutrition and sustainability goals.
View Article and Find Full Text PDFPopulation structure of many marine organisms is spatially patchy and varies within and between years, a phenomenon defined as chaotic genetic patchiness. This results from the combination of planktonic larval dispersal and environmental stochasticity. Additionally, in species with bi-partite life, postsettlement selection can magnify these genetic differences.
View Article and Find Full Text PDFDouble digest restriction site-associated DNA sequencing (ddRADseq) and target capture sequencing methods are used to explore population and phylogenetic questions in non-model organisms. ddRADseq offers a simple and reliable protocol for population genomic studies, however it can result in a large amount of missing data due to allelic dropout. Target capture sequencing offers an opportunity to increase sequencing coverage with little missing data and consistent orthologous loci across samples, although this approach has generally been applied to conserved markers for deeper evolutionary questions.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
November 2016
Mortality events during live transport of Jasus edwardsii rock lobsters are common around the time of season openings in Tasmania, with lobsters from deeper fishing areas with pale shell colouration (brindle) being perceived as more susceptible than shallow-water, red-coloured (red) lobsters. The aims of this study were to assess and predict the vulnerability of brindle and red lobsters to extended emersion exposure using pre- and post-emersion data which included 28 haemolymph biochemical parameters and 5 behaviour traits. No effect of lobster shell colour on haemolymph biochemistry, behaviour traits and their vulnerability to emersion was found.
View Article and Find Full Text PDFThe post-larval or puerulus stage of spiny, or rock, lobsters (Palinuridae) swim many kilometres from open oceans into coastal waters where they subsequently settle. The orientation cues used by the puerulus for this migration are unclear, but are presumed to be critical to finding a place to settle. Understanding this process may help explain the biological processes of dispersal and settlement, and be useful for developing realistic dispersal models.
View Article and Find Full Text PDFThe growing human population must be fed, but historic land-based systems struggle to meet expanding demand. Marine production supports some of the world's poorest people but increasingly provides for the needs of the affluent, either directly by fishing or via fodder-based feeds for marine and terrestrial farming. Here we show the expanding footprint of humans to utilize global ocean productivity to feed themselves.
View Article and Find Full Text PDFThe southern rock lobster, Jasus edwardsii, shows clear phenotypic differences between shallow water (red coloured) and deeper water (pale coloured) individuals. Translocations of individuals from deeper water to shallower waters are currently being trialled as a management strategy to facilitate a phenotypic change from lower value pale colouration, common in deeper waters, to the higher value red colouration found in shallow waters. Although panmixia across the J.
View Article and Find Full Text PDFBackground: Assisted migration or translocation of species to ameliorate effects of habitat loss or changing environment is currently under scrutiny as a conservation tool. A large scale experiment of assisted migration over hundreds of kilometres was tested on a morph from a commercial fishery of southern rock lobster Jasus edwardsii, to enhance depleted populations, improve the yield and sustainability of the fishery, and test resilience to a changing climate.
Methodology And Principal Findings: Approximately 10,000 lower-valued, pale-coloured lobsters were moved from deep water to inshore sites (2 in Tasmania [TAS] and 2 in South Australia [SA]) where the high-value, red morph occurs.
Recently, the importance of the female to population dynamics-especially her non-genetic contribution to offspring fitness or maternal effect-has received much attention in studies of a diverse collection of animal and plant taxa. Of particular interest to fisheries scientists and managers is the role of the demographic structure of the adult component of fish populations in the formation of future year classes. Traditionally, fisheries managers tended to assess whole populations without regard to variation between the individuals within the population.
View Article and Find Full Text PDFComp Biochem Physiol A Mol Integr Physiol
May 2004
Variation in size at hatching is common in demersal spawning organisms, suggesting that processes during embryonic development may be critical in determining growth and development. To examine critical periods during embryonic development in the demersal spawning reef fish Amphiprion melanopus, the rate of oxygen consumption within an egg clutch was compared to morphological changes in the embryos. Oxygen consumption was least on day 1 of development where organ differentiation had not begun (mean 1.
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