Cool study! Are tuna always hungry? A deep dive into stomach-fullness measures in the western and central Pacific Ocean: https://doi.org/10.1071/MF23174
#ecology #animalbehaviour #tuna #fish
Are tuna always hungry? A deep dive into stomach-fullness measures in the western and central Pacific Ocean
Context Understanding tuna diet and its drivers can provide valuable insights into the dynamics of pelagic ecosystems and their capacity to adapt to environmental and human-induced stressors.Aims To reconstruct tropical tuna dietary histories by using different metrics of stomach fullness and to assess their association with fisheries-related, environmental and biological covariates.Methods We examined stomachs from 8229 skipjack (Katsuwonus pelamis), yellowfin (Thunnus albacares) and bigeye tuna (T. obesus) captured in the western and central Pacific Ocean between 2001 and 2021, classified each on the basis of categorical and continuous fullness metrics, then built statistical models to gauge covariate effects.Key results Only models for the binary fullness metric (i.e. empty or non-empty) performed well. Tuna with empty stomachs were more likely to be caught on active gear (e.g. purse seine) and earlier in the day. Skipjack and bigeye tuna with empty stomachs were more likely to be associated with floating objects (e.g. fish-aggregating devices).Conclusions Our results add to the evidence that tropical tunas forage more effectively during the day and more actively when not associated with floating objects. At the individual level, tuna stomach fullness is highly variable.Implications Further research is needed to understand the factors governing this promising indicator of ecosystem change.
Haliotis virginea Gmelin, 1791 and a new abalone from Aotearoa New Zealand (Mollusca: Gastropoda: Haliotidae):
https://doi.org/10.1080/13235818.2024.2390476Using de novo transcriptomes to decipher the relationships in cutthroat trout subspecies (Oncorhynchus clarkii): https://doi.org/10.1111/eva.13735
#evolution #transcriptomics #phylogenetics
Another tool for detecting sex-linked genome sequences! SLRfinder: A method to detect candidate sex-linked regions with linkage disequilibrium clustering: https://doi.org/10.1111/1755-0998.13985
#genomics #evolution #popgen
Wow. Lodge owner praised for spotting guests' invasive clam collection: https://www.1news.co.nz/2024/07/18/lodge-owner-praised-for-spotting-guests-invasive-clam-collection/
Hopefully there are no J. Stewart Smith's of the bivalve world.
Lodge owner praised for spotting guests' invasive clam collection
Andrew Dewing discovered a collection of freshwater gold clams — Corbicula fluminea — when he was inspecting the room of departing guests at his lodge in the central North Island village of Ōwhango.
Marine heatwave promotes population expansion of the invasive ascidian Symplegma brakenhielmi: https://doi.org/10.1007/s10530-024-03296-4
Pretty amazing what ascidians can grow on.
#ecology #invasivespecies
Marine heatwave promotes population expansion of the invasive ascidian Symplegma brakenhielmi - Biological Invasions
The global increase in frequency and severity of marine heatwaves (MHWs) is highlighting the impact these extreme climatic events can have on marine ecosystems. Throughout the summer of 2021/2022 northeastern Aotearoa/New Zealand suffered an unprecedented MHW. Worst impacted areas, such as the semi-enclosed Te Moananui-ā-Toi/Tīkapa Moana/Hauraki Gulf, experienced more than three continual months of temperatures at or above the climatological mean maximum (20.7 °C). During this period, we observed a rapid increase in the abundance and cover of the invasive, warm-affinity colonial ascidian Symplegma brakenhielmi on temperate rocky reefs. Population expansion of this species has not previously been linked to MHW events. Benthic monitoring as water temperatures cooled showed a sharp decrease in S. brakenhielmi abundance, but not complete disappearance, and the coverage of individually monitored colonies also declined. There was no observed increase in abundance or cover throughout the summer of 2022/2023, a potential consequence of cooler water temperatures and multiple cyclones. Observed impacts included the growth of S. brakenhielmi over other sessile invertebrate and macroalgal species, as well as on highly mobile spiny lobster, suggesting that this species can have a variety of impacts on temperate rocky reefs. In the future, as ocean temperatures continue to warm, these findings provide insight into what we can expect and highlight how MHW can facilitate the rapid expansion and integration of non-native, warm-affinity species into temperate reef ecosystems.
Habitat suitability of Aotearoa New Zealand for the recently invaded gold clam (Corbicula fluminea): https://doi.org/10.1080/00288330.2024.2368856
#invasivespecies #biosecurity #ecology
Priority effects transcend scales and disciplines in biology: https://doi.org/10.1016/j.tree.2024.02.004
#ecology #evolution
The radiation of New Zealand’s skinks and geckos is associated with distinct viromes: https://doi.org/10.1186/s12862-024-02269-4
#virome #genomics #biodiversity #biogeography
The radiation of New Zealand’s skinks and geckos is associated with distinct viromes - BMC Ecology and Evolution
Background New Zealand is home to over 120 native endemic species of skinks and geckos that radiated over the last 20–40 million years, likely driven by the exploitation of diverse habitats formed during the Miocene. The recent radiation of animal hosts may facilitate cross-species virus transmission, likely reflecting their close genetic relationships and therefore relatively low barriers for viruses to emerge in new hosts. Conversely, as animal hosts adapt to new niches, even within specific geographic locations, so too could their viruses. Consequently, animals that have niche-specialised following radiations may be expected to harbour genetically distinct viruses. Through a metatranscriptomic analysis of eight of New Zealand’s native skink and gecko species, as well as the only introduced lizard species, the rainbow skink (Lampropholis delicata), we aimed to reveal the diversity of viruses in these hosts and determine whether and how the radiation of skinks and geckos in New Zealand has impacted virus diversity and evolution. Results We identified a total of 15 novel reptilian viruses spanning 11 different viral families, across seven of the nine species sampled. Notably, we detected no viral host-switching among the native animals analysed, even between those sampled from the same geographic location. This is compatible with the idea that host speciation has likely resulted in isolated, niche-constrained viral populations that have prevented cross-species transmission. Using a protein structural similarity-based approach, we further identified a highly divergent bunya-like virus that potentially formed a new family within the Bunyavirales. Conclusions This study has broadened our understanding of reptilian viruses within New Zealand and illustrates how niche adaptation may limit viral-host interactions.
The development of multiplex #PCR assays for the rapid identification of multiple #Saccostrea species, and their practical applications in restoration and aquaculture:
https://doi.org/10.1186/s12862-024-02250-1
#oysters #biodiversity #genetics #species
The development of multiplex PCR assays for the rapid identification of multiple Saccostrea species, and their practical applications in restoration and aquaculture - BMC Ecology and Evolution
Background The ecology and biology of oysters (Ostreidae) across the tropics is poorly understood. Morphological plasticity and shared characteristics among oysters have resulted in the misidentification of species, creating challenges for understanding basic species-specific biological information that is required for restoration and aquaculture. Genetic barcoding has proven essential for accurate species identification and understanding species geographic ranges. To reduce the costs of molecular species identification we developed multiplex assays using the cytochrome c oxidase subunit I (COI or cox1) barcoding gene for the rapid identification of five species of oysters within the genus Saccostrea that are commonly found in Queensland, Australia: Saccostrea glomerata, Saccostrea lineage B, Saccostrea lineage F, Saccostrea lineage G, and Saccostrea spathulata (lineage J). Results Multiplex assays were successful in species-specific amplification of targeted species. The practical application of these primers was tested on wild spat collected from a pilot restoration project in Moreton Bay, Queensland, with identified species (S. glomerata, lineage B and lineage G) validated by Sanger sequencing. DNA sampling by extraction of oyster pallial fluid was also tested on adult oysters collected from the Noosa estuary in Queensland to assess whether oysters were able to be identified non-destructively. DNA concentrations as low as 1 ng/ μL still amplified in most cases, allowing for identification, and mortality at 6 weeks post pallial fluid collection was low (3 out of 104 sampled oysters). Conclusion These multiplex assays will be essential tools for species identification in future studies, and we successfully demonstrate their practical application in both restoration and aquaculture contexts in Queensland. The multiplex assays developed in this study outline easily replicable methods for the development of additional species-specific primer sets for the rapid identification of other species of Saccostrea found across the Indo-Pacific, which will be instrumental in unravelling the taxonomic ambiguities within this genus in tropical regions.
